diff --git a/packages/browser/jest.config.js b/packages/browser/jest.config.js
deleted file mode 100644
index f9cd8056a454..000000000000
--- a/packages/browser/jest.config.js
+++ /dev/null
@@ -1,7 +0,0 @@
-const baseConfig = require('../../jest/jest.config.js');
-
-module.exports = {
-  ...baseConfig,
-  testEnvironment: 'jsdom',
-  testMatch: ['<rootDir>/test/unit/**/*.test.ts'],
-};
diff --git a/packages/browser/package.json b/packages/browser/package.json
index ff719729e534..221f8a492a02 100644
--- a/packages/browser/package.json
+++ b/packages/browser/package.json
@@ -70,9 +70,8 @@
     "fix": "eslint . --format stylish --fix",
     "lint": "eslint . --format stylish",
     "size:check": "cat build/bundles/bundle.min.js | gzip -9 | wc -c | awk '{$1=$1/1024; print \"ES2017: \",$1,\"kB\";}'",
-    "test": "yarn test:unit",
-    "test:unit": "jest",
-    "test:unit:watch": "jest --watch",
+    "test": "vitest run",
+    "test:watch": "vitest --watch",
     "yalc:publish": "yalc publish --push --sig"
   },
   "volta": {
diff --git a/packages/browser/test/unit/eventbuilder.test.ts b/packages/browser/test/eventbuilder.test.ts
similarity index 92%
rename from packages/browser/test/unit/eventbuilder.test.ts
rename to packages/browser/test/eventbuilder.test.ts
index e28b283107c3..0f43e7495efd 100644
--- a/packages/browser/test/unit/eventbuilder.test.ts
+++ b/packages/browser/test/eventbuilder.test.ts
@@ -1,10 +1,15 @@
-import { defaultStackParser } from '../../src';
-import { eventFromUnknownInput } from '../../src/eventbuilder';
+/**
+ * @vitest-environment jsdom
+ */
 
-jest.mock('@sentry/core', () => {
-  const original = jest.requireActual('@sentry/core');
+import { afterEach, describe, expect, it, vi } from 'vitest';
+
+import { defaultStackParser } from '../src';
+import { eventFromUnknownInput } from '../src/eventbuilder';
+
+vi.mock('@sentry/core', async requireActual => {
   return {
-    ...original,
+    ...((await requireActual()) as any),
     getClient() {
       return {
         getOptions(): any {
@@ -21,7 +26,7 @@ class MyTestClass {
 }
 
 afterEach(() => {
-  jest.resetAllMocks();
+  vi.resetAllMocks();
 });
 
 describe('eventFromUnknownInput', () => {
diff --git a/packages/browser/test/unit/helper/browser-client-options.ts b/packages/browser/test/helper/browser-client-options.ts
similarity index 87%
rename from packages/browser/test/unit/helper/browser-client-options.ts
rename to packages/browser/test/helper/browser-client-options.ts
index 867e6a9e6e6e..619baab13bad 100644
--- a/packages/browser/test/unit/helper/browser-client-options.ts
+++ b/packages/browser/test/helper/browser-client-options.ts
@@ -1,7 +1,7 @@
 import { createTransport } from '@sentry/core';
 import { resolvedSyncPromise } from '@sentry/utils';
 
-import type { BrowserClientOptions } from '../../../src/client';
+import type { BrowserClientOptions } from '../../src/client';
 
 export function getDefaultBrowserClientOptions(options: Partial<BrowserClientOptions> = {}): BrowserClientOptions {
   return {
diff --git a/packages/browser/test/unit/index.bundle.feedback.test.ts b/packages/browser/test/index.bundle.feedback.test.ts
similarity index 76%
rename from packages/browser/test/unit/index.bundle.feedback.test.ts
rename to packages/browser/test/index.bundle.feedback.test.ts
index 99516cca295e..47beaa33d07c 100644
--- a/packages/browser/test/unit/index.bundle.feedback.test.ts
+++ b/packages/browser/test/index.bundle.feedback.test.ts
@@ -1,7 +1,9 @@
+import { describe, expect, it } from 'vitest';
+
 import { browserTracingIntegrationShim, replayIntegrationShim } from '@sentry-internal/integration-shims';
-import { feedbackAsyncIntegration } from '../../src';
+import { feedbackAsyncIntegration } from '../src';
 
-import * as FeedbackBundle from '../../src/index.bundle.feedback';
+import * as FeedbackBundle from '../src/index.bundle.feedback';
 
 describe('index.bundle.feedback', () => {
   it('has correct exports', () => {
diff --git a/packages/browser/test/unit/index.bundle.replay.test.ts b/packages/browser/test/index.bundle.replay.test.ts
similarity index 77%
rename from packages/browser/test/unit/index.bundle.replay.test.ts
rename to packages/browser/test/index.bundle.replay.test.ts
index 0fdbf95fe3e4..7efbe9ffb5b8 100644
--- a/packages/browser/test/unit/index.bundle.replay.test.ts
+++ b/packages/browser/test/index.bundle.replay.test.ts
@@ -1,7 +1,9 @@
+import { describe, expect, it } from 'vitest';
+
 import { browserTracingIntegrationShim, feedbackIntegrationShim } from '@sentry-internal/integration-shims';
-import { replayIntegration } from '../../src';
+import { replayIntegration } from '../src';
 
-import * as ReplayBundle from '../../src/index.bundle.replay';
+import * as ReplayBundle from '../src/index.bundle.replay';
 
 describe('index.bundle.replay', () => {
   it('has correct exports', () => {
diff --git a/packages/browser/test/unit/index.bundle.test.ts b/packages/browser/test/index.bundle.test.ts
similarity index 84%
rename from packages/browser/test/unit/index.bundle.test.ts
rename to packages/browser/test/index.bundle.test.ts
index 1535d74d6b6a..4b4618e2f4eb 100644
--- a/packages/browser/test/unit/index.bundle.test.ts
+++ b/packages/browser/test/index.bundle.test.ts
@@ -1,10 +1,12 @@
+import { describe, expect, it } from 'vitest';
+
 import {
   browserTracingIntegrationShim,
   feedbackIntegrationShim,
   replayIntegrationShim,
 } from '@sentry-internal/integration-shims';
 
-import * as Bundle from '../../src/index.bundle';
+import * as Bundle from '../src/index.bundle';
 
 describe('index.bundle', () => {
   it('has correct exports', () => {
diff --git a/packages/browser/test/unit/index.bundle.tracing.replay.feedback.test.ts b/packages/browser/test/index.bundle.tracing.replay.feedback.test.ts
similarity index 75%
rename from packages/browser/test/unit/index.bundle.tracing.replay.feedback.test.ts
rename to packages/browser/test/index.bundle.tracing.replay.feedback.test.ts
index 2d62f247a1da..e5a454b532e9 100644
--- a/packages/browser/test/unit/index.bundle.tracing.replay.feedback.test.ts
+++ b/packages/browser/test/index.bundle.tracing.replay.feedback.test.ts
@@ -1,6 +1,8 @@
-import { browserTracingIntegration, feedbackAsyncIntegration, replayIntegration } from '../../src';
+import { describe, expect, it } from 'vitest';
 
-import * as TracingReplayFeedbackBundle from '../../src/index.bundle.tracing.replay.feedback';
+import { browserTracingIntegration, feedbackAsyncIntegration, replayIntegration } from '../src';
+
+import * as TracingReplayFeedbackBundle from '../src/index.bundle.tracing.replay.feedback';
 
 describe('index.bundle.tracing.replay.feedback', () => {
   it('has correct exports', () => {
diff --git a/packages/browser/test/unit/index.bundle.tracing.replay.test.ts b/packages/browser/test/index.bundle.tracing.replay.test.ts
similarity index 81%
rename from packages/browser/test/unit/index.bundle.tracing.replay.test.ts
rename to packages/browser/test/index.bundle.tracing.replay.test.ts
index 2cd3f5dca0f0..fa81d1b19aae 100644
--- a/packages/browser/test/unit/index.bundle.tracing.replay.test.ts
+++ b/packages/browser/test/index.bundle.tracing.replay.test.ts
@@ -1,7 +1,9 @@
+import { describe, expect, it } from 'vitest';
+
 import { feedbackIntegrationShim } from '@sentry-internal/integration-shims';
-import { browserTracingIntegration, replayIntegration } from '../../src';
+import { browserTracingIntegration, replayIntegration } from '../src';
 
-import * as TracingReplayBundle from '../../src/index.bundle.tracing.replay';
+import * as TracingReplayBundle from '../src/index.bundle.tracing.replay';
 
 describe('index.bundle.tracing.replay', () => {
   it('has correct exports', () => {
diff --git a/packages/browser/test/unit/index.bundle.tracing.test.ts b/packages/browser/test/index.bundle.tracing.test.ts
similarity index 75%
rename from packages/browser/test/unit/index.bundle.tracing.test.ts
rename to packages/browser/test/index.bundle.tracing.test.ts
index 942d185b2e91..dc786fd31a61 100644
--- a/packages/browser/test/unit/index.bundle.tracing.test.ts
+++ b/packages/browser/test/index.bundle.tracing.test.ts
@@ -1,7 +1,9 @@
+import { describe, expect, it } from 'vitest';
+
 import { feedbackIntegrationShim, replayIntegrationShim } from '@sentry-internal/integration-shims';
-import { browserTracingIntegration } from '../../src';
+import { browserTracingIntegration } from '../src';
 
-import * as TracingBundle from '../../src/index.bundle.tracing';
+import * as TracingBundle from '../src/index.bundle.tracing';
 
 describe('index.bundle.tracing', () => {
   it('has correct exports', () => {
diff --git a/packages/browser/test/unit/index.test.ts b/packages/browser/test/index.test.ts
similarity index 83%
rename from packages/browser/test/unit/index.test.ts
rename to packages/browser/test/index.test.ts
index 34c4845cac13..eb2fb6104b11 100644
--- a/packages/browser/test/unit/index.test.ts
+++ b/packages/browser/test/index.test.ts
@@ -1,3 +1,10 @@
+/**
+ * @vitest-environment jsdom
+ */
+
+import type { Mock } from 'vitest';
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+
 import {
   SDK_VERSION,
   getGlobalScope,
@@ -8,7 +15,7 @@ import {
 } from '@sentry/core';
 import * as utils from '@sentry/utils';
 
-import { setCurrentClient } from '../../src';
+import { setCurrentClient } from '../src';
 import {
   BrowserClient,
   Scope,
@@ -22,7 +29,7 @@ import {
   getCurrentScope,
   init,
   showReportDialog,
-} from '../../src';
+} from '../src';
 import { getDefaultBrowserClientOptions } from './helper/browser-client-options';
 import { makeSimpleTransport } from './mocks/simpletransport';
 
@@ -31,16 +38,15 @@ const dsn = 'https://53039209a22b4ec1bcc296a3c9fdecd6@sentry.io/4291';
 // eslint-disable-next-line no-var
 declare var global: any;
 
-jest.mock('@sentry/core', () => {
-  const original = jest.requireActual('@sentry/core');
+vi.mock('@sentry/core', async requireActual => {
   return {
-    ...original,
-    getReportDialogEndpoint: jest.fn(),
+    ...((await requireActual()) as any),
+    getReportDialogEndpoint: vi.fn(),
   };
 });
 
 describe('SentryBrowser', () => {
-  const beforeSend = jest.fn(event => event);
+  const beforeSend = vi.fn(event => event);
 
   beforeEach(() => {
     getGlobalScope().clear();
@@ -84,7 +90,7 @@ describe('SentryBrowser', () => {
 
   describe('showReportDialog', () => {
     beforeEach(() => {
-      (getReportDialogEndpoint as jest.Mock).mockReset();
+      (getReportDialogEndpoint as Mock).mockReset();
     });
 
     describe('user', () => {
@@ -145,14 +151,14 @@ describe('SentryBrowser', () => {
     });
 
     describe('onClose', () => {
-      const dummyErrorHandler = jest.fn();
+      const dummyErrorHandler = vi.fn();
       beforeEach(() => {
-        // this prevents jest-environment-jsdom from failing the test
+        // this prevents vi-environment-jsdom from failing the test
         // when an error in `onClose` is thrown
         // it does not prevent errors thrown directly inside the test,
         // so we don't have to worry about tests passing that should
         // otherwise fail
-        // see: https://github.com/jestjs/jest/blob/main/packages/jest-environment-jsdom/src/index.ts#L95-L115
+        // see: https://github.com/vijs/vi/blob/main/packages/vi-environment-jsdom/src/index.ts#L95-L115
         WINDOW.addEventListener('error', dummyErrorHandler);
       });
 
@@ -166,7 +172,7 @@ describe('SentryBrowser', () => {
       };
 
       it('should call `onClose` when receiving `__sentry_reportdialog_closed__` MessageEvent', async () => {
-        const onClose = jest.fn();
+        const onClose = vi.fn();
 
         showReportDialog({ onClose });
 
@@ -179,7 +185,7 @@ describe('SentryBrowser', () => {
       });
 
       it('should call `onClose` only once even if it throws', async () => {
-        const onClose = jest.fn(() => {
+        const onClose = vi.fn(() => {
           throw new Error();
         });
 
@@ -194,7 +200,7 @@ describe('SentryBrowser', () => {
       });
 
       it('should not call `onClose` for other MessageEvents', async () => {
-        const onClose = jest.fn();
+        const onClose = vi.fn();
 
         showReportDialog({ onClose });
 
@@ -236,49 +242,52 @@ describe('SentryBrowser', () => {
       expect(event.exception.values[0]?.stacktrace.frames).not.toHaveLength(0);
     });
 
-    it('should capture a message', done => {
-      const options = getDefaultBrowserClientOptions({
-        beforeSend: event => {
-          expect(event.message).toBe('test');
-          expect(event.exception).toBeUndefined();
-          done();
-          return event;
-        },
-        dsn,
-      });
-      setCurrentClient(new BrowserClient(options));
-      captureMessage('test');
-    });
-
-    it('should capture an event', done => {
-      const options = getDefaultBrowserClientOptions({
-        beforeSend: event => {
-          expect(event.message).toBe('event');
-          expect(event.exception).toBeUndefined();
-          done();
-          return event;
-        },
-        dsn,
-      });
-      setCurrentClient(new BrowserClient(options));
-      captureEvent({ message: 'event' });
-    });
-
-    it('should set `platform` on events', done => {
-      const options = getDefaultBrowserClientOptions({
-        beforeSend: event => {
-          expect(event.platform).toBe('javascript');
-          done();
-          return event;
-        },
-        dsn,
-      });
-      setCurrentClient(new BrowserClient(options));
-      captureEvent({ message: 'event' });
-    });
+    it('should capture a message', () =>
+      new Promise<void>(resolve => {
+        const options = getDefaultBrowserClientOptions({
+          beforeSend: event => {
+            expect(event.message).toBe('test');
+            expect(event.exception).toBeUndefined();
+            resolve();
+            return event;
+          },
+          dsn,
+        });
+        setCurrentClient(new BrowserClient(options));
+        captureMessage('test');
+      }));
+
+    it('should capture an event', () =>
+      new Promise<void>(resolve => {
+        const options = getDefaultBrowserClientOptions({
+          beforeSend: event => {
+            expect(event.message).toBe('event');
+            expect(event.exception).toBeUndefined();
+            resolve();
+            return event;
+          },
+          dsn,
+        });
+        setCurrentClient(new BrowserClient(options));
+        captureEvent({ message: 'event' });
+      }));
+
+    it('should set `platform` on events', () =>
+      new Promise<void>(resolve => {
+        const options = getDefaultBrowserClientOptions({
+          beforeSend: event => {
+            expect(event.platform).toBe('javascript');
+            resolve();
+            return event;
+          },
+          dsn,
+        });
+        setCurrentClient(new BrowserClient(options));
+        captureEvent({ message: 'event' });
+      }));
 
     it('should not dedupe an event on bound client', async () => {
-      const localBeforeSend = jest.fn();
+      const localBeforeSend = vi.fn();
       const options = getDefaultBrowserClientOptions({
         beforeSend: localBeforeSend,
         dsn,
@@ -295,7 +304,7 @@ describe('SentryBrowser', () => {
     });
 
     it('should use inboundfilter rules of bound client', async () => {
-      const localBeforeSend = jest.fn();
+      const localBeforeSend = vi.fn();
       const options = getDefaultBrowserClientOptions({
         beforeSend: localBeforeSend,
         dsn,
@@ -374,7 +383,7 @@ describe('SentryBrowser initialization', () => {
     });
 
     it('uses SDK source from global for package name', () => {
-      const spy = jest.spyOn(utils, 'getSDKSource').mockReturnValue('cdn');
+      const spy = vi.spyOn(utils, 'getSDKSource').mockReturnValue('cdn');
       init({ dsn });
 
       const sdkData = getClient()?.getOptions()._metadata?.sdk || {};
diff --git a/packages/browser/test/unit/integrations/breadcrumbs.test.ts b/packages/browser/test/integrations/breadcrumbs.test.ts
similarity index 82%
rename from packages/browser/test/unit/integrations/breadcrumbs.test.ts
rename to packages/browser/test/integrations/breadcrumbs.test.ts
index 15ad5f3e4261..770578ef77b5 100644
--- a/packages/browser/test/unit/integrations/breadcrumbs.test.ts
+++ b/packages/browser/test/integrations/breadcrumbs.test.ts
@@ -1,6 +1,8 @@
+import { describe, expect, it, vi } from 'vitest';
+
 import * as SentryCore from '@sentry/core';
 
-import { BrowserClient, breadcrumbsIntegration, flush } from '../../../src';
+import { BrowserClient, breadcrumbsIntegration, flush } from '../../src';
 import { getDefaultBrowserClientOptions } from '../helper/browser-client-options';
 
 describe('Breadcrumbs', () => {
@@ -14,7 +16,7 @@ describe('Breadcrumbs', () => {
     SentryCore.setCurrentClient(client);
     client.init();
 
-    const addBreadcrumbSpy = jest.spyOn(SentryCore, 'addBreadcrumb').mockImplementation(() => {});
+    const addBreadcrumbSpy = vi.spyOn(SentryCore, 'addBreadcrumb').mockImplementation(() => {});
 
     client.captureMessage('test');
     await flush(2000);
diff --git a/packages/browser/test/unit/integrations/contextlines.test.ts b/packages/browser/test/integrations/contextlines.test.ts
similarity index 96%
rename from packages/browser/test/unit/integrations/contextlines.test.ts
rename to packages/browser/test/integrations/contextlines.test.ts
index 5f19bd2b41a7..783cc36fec89 100644
--- a/packages/browser/test/unit/integrations/contextlines.test.ts
+++ b/packages/browser/test/integrations/contextlines.test.ts
@@ -1,6 +1,8 @@
+import { describe, expect, it } from 'vitest';
+
 import type { StackFrame } from '@sentry/types';
 
-import { applySourceContextToFrame } from '../../../src/integrations/contextlines';
+import { applySourceContextToFrame } from '../../src/integrations/contextlines';
 
 const lines = ['line1', 'line2', 'line3', 'line4', 'line5', 'line6', 'line7', 'line8', 'line9'];
 describe('ContextLines', () => {
diff --git a/packages/browser/test/unit/integrations/helpers.test.ts b/packages/browser/test/integrations/helpers.test.ts
similarity index 97%
rename from packages/browser/test/unit/integrations/helpers.test.ts
rename to packages/browser/test/integrations/helpers.test.ts
index 080ab4c5cd0f..37806e06f8a9 100644
--- a/packages/browser/test/unit/integrations/helpers.test.ts
+++ b/packages/browser/test/integrations/helpers.test.ts
@@ -1,6 +1,8 @@
+import { describe, expect, it, vi } from 'vitest';
+
 import type { WrappedFunction } from '@sentry/types';
 
-import { wrap } from '../../../src/helpers';
+import { wrap } from '../../src/helpers';
 
 describe('internal wrap()', () => {
   it('should wrap only functions', () => {
@@ -56,7 +58,7 @@ describe('internal wrap()', () => {
 
   it('calls "before" function when invoking wrapped function', () => {
     const fn = (() => 1337) as WrappedFunction;
-    const before = jest.fn();
+    const before = vi.fn();
 
     const wrapped = wrap(fn, {}, before);
     wrapped();
@@ -115,7 +117,7 @@ describe('internal wrap()', () => {
   });
 
   it('calls the original function', () => {
-    const fn = jest.fn();
+    const fn = vi.fn();
 
     wrap(fn)(123, 'Rick');
 
diff --git a/packages/browser/test/unit/integrations/reportingobserver.test.ts b/packages/browser/test/integrations/reportingobserver.test.ts
similarity index 94%
rename from packages/browser/test/unit/integrations/reportingobserver.test.ts
rename to packages/browser/test/integrations/reportingobserver.test.ts
index aba669286f44..9571d59d03d0 100644
--- a/packages/browser/test/unit/integrations/reportingobserver.test.ts
+++ b/packages/browser/test/integrations/reportingobserver.test.ts
@@ -1,20 +1,22 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+
 import * as SentryCore from '@sentry/core';
 import type { Client } from '@sentry/types';
 
-import { reportingObserverIntegration } from '../../../src/integrations/reportingobserver';
+import { reportingObserverIntegration } from '../../src/integrations/reportingobserver';
 
 const mockScope = {
-  setExtra: jest.fn(),
+  setExtra: vi.fn(),
 };
 
-const withScope = jest.fn(callback => {
+const withScope = vi.fn(callback => {
   return callback(mockScope);
 });
 
-const captureMessage = jest.fn();
+const captureMessage = vi.fn();
 
-const mockReportingObserverConstructor = jest.fn();
-const mockObserve = jest.fn();
+const mockReportingObserverConstructor = vi.fn();
+const mockObserve = vi.fn();
 
 class MockReportingObserver {
   public observe: () => void = mockObserve;
@@ -32,13 +34,13 @@ describe('ReportingObserver', () => {
 
     mockClient = {} as Client;
 
-    jest.spyOn(SentryCore, 'captureMessage').mockImplementation(captureMessage);
-    jest.spyOn(SentryCore, 'getClient').mockImplementation(() => mockClient);
-    jest.spyOn(SentryCore, 'withScope').mockImplementation(withScope);
+    vi.spyOn(SentryCore, 'captureMessage').mockImplementation(captureMessage);
+    vi.spyOn(SentryCore, 'getClient').mockImplementation(() => mockClient);
+    vi.spyOn(SentryCore, 'withScope').mockImplementation(withScope);
   });
 
   afterEach(() => {
-    jest.clearAllMocks();
+    vi.clearAllMocks();
     delete (global as any).ReportingObserver;
   });
 
diff --git a/packages/browser/test/unit/mocks/simpletransport.ts b/packages/browser/test/mocks/simpletransport.ts
similarity index 100%
rename from packages/browser/test/unit/mocks/simpletransport.ts
rename to packages/browser/test/mocks/simpletransport.ts
diff --git a/packages/browser/test/unit/profiling/integration.test.ts b/packages/browser/test/profiling/integration.test.ts
similarity index 84%
rename from packages/browser/test/unit/profiling/integration.test.ts
rename to packages/browser/test/profiling/integration.test.ts
index b5c4ad7c82a5..2f653563fc1a 100644
--- a/packages/browser/test/unit/profiling/integration.test.ts
+++ b/packages/browser/test/profiling/integration.test.ts
@@ -1,11 +1,17 @@
+/**
+ * @vitest-environment jsdom
+ */
+
+import { describe, expect, it, vi } from 'vitest';
+
 import type { BrowserClient } from '@sentry/browser';
 import * as Sentry from '@sentry/browser';
 
-import type { JSSelfProfile } from '../../../src/profiling/jsSelfProfiling';
+import type { JSSelfProfile } from '../../src/profiling/jsSelfProfiling';
 
 describe('BrowserProfilingIntegration', () => {
   it('pageload profiles follow regular transaction code path', async () => {
-    const stopProfile = jest.fn().mockImplementation((): Promise<JSSelfProfile> => {
+    const stopProfile = vi.fn().mockImplementation((): Promise<JSSelfProfile> => {
       return Promise.resolve({
         frames: [{ name: 'pageload_fn', line: 1, column: 1 }],
         stacks: [{ frameId: 0, parentId: undefined }],
@@ -30,8 +36,8 @@ describe('BrowserProfilingIntegration', () => {
     // @ts-expect-error this is a mock constructor
     window.Profiler = MockProfiler;
 
-    const flush = jest.fn().mockImplementation(() => Promise.resolve(true));
-    const send = jest.fn().mockImplementation(() => Promise.resolve());
+    const flush = vi.fn().mockImplementation(() => Promise.resolve(true));
+    const send = vi.fn().mockImplementation(() => Promise.resolve());
     Sentry.init({
       tracesSampleRate: 1,
       profilesSampleRate: 1,
diff --git a/packages/browser/test/unit/profiling/utils.test.ts b/packages/browser/test/profiling/utils.test.ts
similarity index 94%
rename from packages/browser/test/unit/profiling/utils.test.ts
rename to packages/browser/test/profiling/utils.test.ts
index 573d9dbb335e..27e81c3208dc 100644
--- a/packages/browser/test/unit/profiling/utils.test.ts
+++ b/packages/browser/test/profiling/utils.test.ts
@@ -1,3 +1,9 @@
+/**
+ * @vitest-environment jsdom
+ */
+
+import { afterAll, afterEach, beforeEach, describe, expect, it } from 'vitest';
+
 import { TextDecoder, TextEncoder } from 'util';
 const patchedEncoder = (!global.window.TextEncoder && (global.window.TextEncoder = TextEncoder)) || true;
 // @ts-expect-error patch the encoder on the window, else importing JSDOM fails (deleted in afterAll)
@@ -5,8 +11,8 @@ const patchedDecoder = (!global.window.TextDecoder && (global.window.TextDecoder
 
 import { JSDOM } from 'jsdom';
 
-import type { JSSelfProfile } from '../../../src/profiling/jsSelfProfiling';
-import { convertJSSelfProfileToSampledFormat } from '../../../src/profiling/utils';
+import type { JSSelfProfile } from '../../src/profiling/jsSelfProfiling';
+import { convertJSSelfProfileToSampledFormat } from '../../src/profiling/utils';
 
 const makeJSProfile = (partial: Partial<JSSelfProfile> = {}): JSSelfProfile => {
   return {
diff --git a/packages/browser/test/unit/sdk.test.ts b/packages/browser/test/sdk.test.ts
similarity index 78%
rename from packages/browser/test/unit/sdk.test.ts
rename to packages/browser/test/sdk.test.ts
index 667ad850fb36..31178bc84423 100644
--- a/packages/browser/test/unit/sdk.test.ts
+++ b/packages/browser/test/sdk.test.ts
@@ -1,11 +1,18 @@
+/**
+ * @vitest-environment jsdom
+ */
+
 /* eslint-disable @typescript-eslint/unbound-method */
+import type { Mock } from 'vitest';
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+
 import { Scope, createTransport } from '@sentry/core';
 import type { Client, Integration } from '@sentry/types';
 import { resolvedSyncPromise } from '@sentry/utils';
 
-import type { BrowserOptions } from '../../src';
-import { WINDOW } from '../../src';
-import { init } from '../../src/sdk';
+import type { BrowserOptions } from '../src';
+import { WINDOW } from '../src';
+import { init } from '../src/sdk';
 
 const PUBLIC_DSN = 'https://username@domain/123';
 
@@ -20,16 +27,15 @@ function getDefaultBrowserOptions(options: Partial<BrowserOptions> = {}): Browse
 
 export class MockIntegration implements Integration {
   public name: string;
-  public setupOnce: () => void = jest.fn();
+  public setupOnce: () => void = vi.fn();
   public constructor(name: string) {
     this.name = name;
   }
 }
 
-jest.mock('@sentry/core', () => {
-  const original = jest.requireActual('@sentry/core');
+vi.mock('@sentry/core', async requireActual => {
   return {
-    ...original,
+    ...((await requireActual()) as any),
     getCurrentHub(): {
       bindClient(client: Client): boolean;
       getClient(): boolean;
@@ -53,11 +59,11 @@ jest.mock('@sentry/core', () => {
 
 describe('init', () => {
   beforeEach(() => {
-    jest.clearAllMocks();
+    vi.clearAllMocks();
   });
 
   afterAll(() => {
-    jest.resetAllMocks();
+    vi.resetAllMocks();
   });
 
   test('installs default integrations', () => {
@@ -69,8 +75,8 @@ describe('init', () => {
 
     init(options);
 
-    expect(DEFAULT_INTEGRATIONS[0]!.setupOnce as jest.Mock).toHaveBeenCalledTimes(1);
-    expect(DEFAULT_INTEGRATIONS[1]!.setupOnce as jest.Mock).toHaveBeenCalledTimes(1);
+    expect(DEFAULT_INTEGRATIONS[0]!.setupOnce as Mock).toHaveBeenCalledTimes(1);
+    expect(DEFAULT_INTEGRATIONS[1]!.setupOnce as Mock).toHaveBeenCalledTimes(1);
   });
 
   test("doesn't install default integrations if told not to", () => {
@@ -81,8 +87,8 @@ describe('init', () => {
     const options = getDefaultBrowserOptions({ dsn: PUBLIC_DSN, defaultIntegrations: false });
     init(options);
 
-    expect(DEFAULT_INTEGRATIONS[0]!.setupOnce as jest.Mock).toHaveBeenCalledTimes(0);
-    expect(DEFAULT_INTEGRATIONS[1]!.setupOnce as jest.Mock).toHaveBeenCalledTimes(0);
+    expect(DEFAULT_INTEGRATIONS[0]!.setupOnce as Mock).toHaveBeenCalledTimes(0);
+    expect(DEFAULT_INTEGRATIONS[1]!.setupOnce as Mock).toHaveBeenCalledTimes(0);
   });
 
   it('installs merged default integrations, with overrides provided through options', () => {
@@ -100,10 +106,10 @@ describe('init', () => {
 
     init(options);
     // 'MockIntegration 1' should be overridden by the one with the same name provided through options
-    expect(DEFAULT_INTEGRATIONS[0]!.setupOnce as jest.Mock).toHaveBeenCalledTimes(0);
-    expect(DEFAULT_INTEGRATIONS[1]!.setupOnce as jest.Mock).toHaveBeenCalledTimes(1);
-    expect(integrations[0]!.setupOnce as jest.Mock).toHaveBeenCalledTimes(1);
-    expect(integrations[1]!.setupOnce as jest.Mock).toHaveBeenCalledTimes(1);
+    expect(DEFAULT_INTEGRATIONS[0]!.setupOnce as Mock).toHaveBeenCalledTimes(0);
+    expect(DEFAULT_INTEGRATIONS[1]!.setupOnce as Mock).toHaveBeenCalledTimes(1);
+    expect(integrations[0]!.setupOnce as Mock).toHaveBeenCalledTimes(1);
+    expect(integrations[1]!.setupOnce as Mock).toHaveBeenCalledTimes(1);
   });
 
   it('installs integrations returned from a callback function', () => {
@@ -124,9 +130,9 @@ describe('init', () => {
 
     init(options);
 
-    expect(DEFAULT_INTEGRATIONS[0]!.setupOnce as jest.Mock).toHaveBeenCalledTimes(1);
-    expect(newIntegration.setupOnce as jest.Mock).toHaveBeenCalledTimes(1);
-    expect(DEFAULT_INTEGRATIONS[1]!.setupOnce as jest.Mock).toHaveBeenCalledTimes(0);
+    expect(DEFAULT_INTEGRATIONS[0]!.setupOnce as Mock).toHaveBeenCalledTimes(1);
+    expect(newIntegration.setupOnce as Mock).toHaveBeenCalledTimes(1);
+    expect(DEFAULT_INTEGRATIONS[1]!.setupOnce as Mock).toHaveBeenCalledTimes(0);
   });
 
   describe('initialization error in browser extension', () => {
@@ -146,7 +152,7 @@ describe('init', () => {
     });
 
     it('logs a browser extension error if executed inside a Chrome extension', () => {
-      const consoleErrorSpy = jest.spyOn(console, 'error').mockImplementation(() => {});
+      const consoleErrorSpy = vi.spyOn(console, 'error').mockImplementation(() => {});
 
       Object.defineProperty(WINDOW, 'chrome', {
         value: { runtime: { id: 'mock-extension-id' } },
@@ -164,7 +170,7 @@ describe('init', () => {
     });
 
     it('logs a browser extension error if executed inside a Firefox/Safari extension', () => {
-      const consoleErrorSpy = jest.spyOn(console, 'error').mockImplementation(() => {});
+      const consoleErrorSpy = vi.spyOn(console, 'error').mockImplementation(() => {});
 
       Object.defineProperty(WINDOW, 'browser', { value: { runtime: { id: 'mock-extension-id' } }, writable: true });
 
@@ -181,7 +187,7 @@ describe('init', () => {
     it.each(['chrome-extension', 'moz-extension', 'ms-browser-extension'])(
       "doesn't log a browser extension error if executed inside an extension running in a dedicated page (%s)",
       extensionProtocol => {
-        const consoleErrorSpy = jest.spyOn(console, 'error').mockImplementation(() => {});
+        const consoleErrorSpy = vi.spyOn(console, 'error').mockImplementation(() => {});
 
         // @ts-expect-error - this is a hack to simulate a dedicated page in a browser extension
         delete WINDOW.location;
@@ -202,7 +208,7 @@ describe('init', () => {
     );
 
     it("doesn't log a browser extension error if executed inside regular browser environment", () => {
-      const consoleErrorSpy = jest.spyOn(console, 'error').mockImplementation(() => {});
+      const consoleErrorSpy = vi.spyOn(console, 'error').mockImplementation(() => {});
 
       init(options);
 
@@ -212,7 +218,7 @@ describe('init', () => {
     });
 
     it("doesn't log a browser extension error if executed inside an NW.js environment", () => {
-      const consoleErrorSpy = jest.spyOn(console, 'error').mockImplementation(() => {});
+      const consoleErrorSpy = vi.spyOn(console, 'error').mockImplementation(() => {});
 
       Object.defineProperty(WINDOW, 'nw', { value: {} });
 
@@ -224,7 +230,7 @@ describe('init', () => {
     });
 
     it("doesn't return a client on initialization error", () => {
-      const consoleErrorSpy = jest.spyOn(console, 'error').mockImplementation(() => {});
+      const consoleErrorSpy = vi.spyOn(console, 'error').mockImplementation(() => {});
 
       Object.defineProperty(WINDOW, 'chrome', {
         value: { runtime: { id: 'mock-extension-id' } },
diff --git a/packages/browser/test/unit/tracekit/chromium.test.ts b/packages/browser/test/tracekit/chromium.test.ts
similarity index 99%
rename from packages/browser/test/unit/tracekit/chromium.test.ts
rename to packages/browser/test/tracekit/chromium.test.ts
index 790f36e0ddc3..36d728f9cbea 100644
--- a/packages/browser/test/unit/tracekit/chromium.test.ts
+++ b/packages/browser/test/tracekit/chromium.test.ts
@@ -1,5 +1,7 @@
-import { exceptionFromError } from '../../../src/eventbuilder';
-import { defaultStackParser as parser } from '../../../src/stack-parsers';
+import { describe, expect, it } from 'vitest';
+
+import { exceptionFromError } from '../../src/eventbuilder';
+import { defaultStackParser as parser } from '../../src/stack-parsers';
 
 describe('Tracekit - Chrome Tests', () => {
   it('should parse Chrome error with no location', () => {
diff --git a/packages/browser/test/unit/tracekit/firefox.test.ts b/packages/browser/test/tracekit/firefox.test.ts
similarity index 98%
rename from packages/browser/test/unit/tracekit/firefox.test.ts
rename to packages/browser/test/tracekit/firefox.test.ts
index 5e05930f8078..4a0d3d90e7dc 100644
--- a/packages/browser/test/unit/tracekit/firefox.test.ts
+++ b/packages/browser/test/tracekit/firefox.test.ts
@@ -1,5 +1,7 @@
-import { exceptionFromError } from '../../../src/eventbuilder';
-import { defaultStackParser as parser } from '../../../src/stack-parsers';
+import { describe, expect, it } from 'vitest';
+
+import { exceptionFromError } from '../../src/eventbuilder';
+import { defaultStackParser as parser } from '../../src/stack-parsers';
 
 describe('Tracekit - Firefox Tests', () => {
   it('should parse Firefox 3 error', () => {
diff --git a/packages/browser/test/unit/tracekit/ie.test.ts b/packages/browser/test/tracekit/ie.test.ts
similarity index 95%
rename from packages/browser/test/unit/tracekit/ie.test.ts
rename to packages/browser/test/tracekit/ie.test.ts
index 53e96b96371f..95d88a6bef34 100644
--- a/packages/browser/test/unit/tracekit/ie.test.ts
+++ b/packages/browser/test/tracekit/ie.test.ts
@@ -1,6 +1,8 @@
+import { describe, expect, it } from 'vitest';
+
 import { createStackParser } from '@sentry/utils';
-import { exceptionFromError } from '../../../src/eventbuilder';
-import { chromeStackLineParser, geckoStackLineParser, winjsStackLineParser } from '../../../src/stack-parsers';
+import { exceptionFromError } from '../../src/eventbuilder';
+import { chromeStackLineParser, geckoStackLineParser, winjsStackLineParser } from '../../src/stack-parsers';
 
 const parser = createStackParser(chromeStackLineParser, geckoStackLineParser, winjsStackLineParser);
 
diff --git a/packages/browser/test/unit/tracekit/misc.test.ts b/packages/browser/test/tracekit/misc.test.ts
similarity index 96%
rename from packages/browser/test/unit/tracekit/misc.test.ts
rename to packages/browser/test/tracekit/misc.test.ts
index 8cb31f9a7868..7e501b8abeef 100644
--- a/packages/browser/test/unit/tracekit/misc.test.ts
+++ b/packages/browser/test/tracekit/misc.test.ts
@@ -1,5 +1,7 @@
-import { exceptionFromError } from '../../../src/eventbuilder';
-import { defaultStackParser as parser } from '../../../src/stack-parsers';
+import { describe, expect, it } from 'vitest';
+
+import { exceptionFromError } from '../../src/eventbuilder';
+import { defaultStackParser as parser } from '../../src/stack-parsers';
 
 describe('Tracekit - Misc Tests', () => {
   it('should parse PhantomJS 1.19 error', () => {
diff --git a/packages/browser/test/unit/tracekit/opera.test.ts b/packages/browser/test/tracekit/opera.test.ts
similarity index 98%
rename from packages/browser/test/unit/tracekit/opera.test.ts
rename to packages/browser/test/tracekit/opera.test.ts
index e86855dc172a..352737fba5d0 100644
--- a/packages/browser/test/unit/tracekit/opera.test.ts
+++ b/packages/browser/test/tracekit/opera.test.ts
@@ -1,7 +1,9 @@
+import { describe, expect, it } from 'vitest';
+
 import { createStackParser } from '@sentry/utils';
 
-import { exceptionFromError } from '../../../src/eventbuilder';
-import { defaultStackParser, opera10StackLineParser, opera11StackLineParser } from '../../../src/stack-parsers';
+import { exceptionFromError } from '../../src/eventbuilder';
+import { defaultStackParser, opera10StackLineParser, opera11StackLineParser } from '../../src/stack-parsers';
 
 const operaParser = createStackParser(opera10StackLineParser, opera11StackLineParser);
 const chromiumParser = defaultStackParser;
diff --git a/packages/browser/test/unit/tracekit/react-native.test.ts b/packages/browser/test/tracekit/react-native.test.ts
similarity index 99%
rename from packages/browser/test/unit/tracekit/react-native.test.ts
rename to packages/browser/test/tracekit/react-native.test.ts
index 9a74e46007b1..c69703fe0c34 100644
--- a/packages/browser/test/unit/tracekit/react-native.test.ts
+++ b/packages/browser/test/tracekit/react-native.test.ts
@@ -1,5 +1,7 @@
-import { exceptionFromError } from '../../../src/eventbuilder';
-import { defaultStackParser as parser } from '../../../src/stack-parsers';
+import { describe, expect, it } from 'vitest';
+
+import { exceptionFromError } from '../../src/eventbuilder';
+import { defaultStackParser as parser } from '../../src/stack-parsers';
 
 describe('Tracekit - React Native Tests', () => {
   it('should parse exceptions for react-native-v8', () => {
diff --git a/packages/browser/test/unit/tracekit/react.test.ts b/packages/browser/test/tracekit/react.test.ts
similarity index 96%
rename from packages/browser/test/unit/tracekit/react.test.ts
rename to packages/browser/test/tracekit/react.test.ts
index 55ffdc34c537..dd737b798d03 100644
--- a/packages/browser/test/unit/tracekit/react.test.ts
+++ b/packages/browser/test/tracekit/react.test.ts
@@ -1,5 +1,7 @@
-import { exceptionFromError } from '../../../src/eventbuilder';
-import { defaultStackParser as parser } from '../../../src/stack-parsers';
+import { describe, expect, it } from 'vitest';
+
+import { exceptionFromError } from '../../src/eventbuilder';
+import { defaultStackParser as parser } from '../../src/stack-parsers';
 
 describe('Tracekit - React Tests', () => {
   it('should correctly parse Invariant Violation errors and use framesToPop to drop the invariant frame', () => {
diff --git a/packages/browser/test/unit/tracekit/safari.test.ts b/packages/browser/test/tracekit/safari.test.ts
similarity index 98%
rename from packages/browser/test/unit/tracekit/safari.test.ts
rename to packages/browser/test/tracekit/safari.test.ts
index 470ed1d7b8dc..ca94df924910 100644
--- a/packages/browser/test/unit/tracekit/safari.test.ts
+++ b/packages/browser/test/tracekit/safari.test.ts
@@ -1,5 +1,7 @@
-import { exceptionFromError } from '../../../src/eventbuilder';
-import { defaultStackParser as parser } from '../../../src/stack-parsers';
+import { describe, expect, it } from 'vitest';
+
+import { exceptionFromError } from '../../src/eventbuilder';
+import { defaultStackParser as parser } from '../../src/stack-parsers';
 
 describe('Tracekit - Safari Tests', () => {
   it('should parse Safari 6 error', () => {
diff --git a/packages/browser/test/unit/tracing/backgroundtab.test.ts b/packages/browser/test/tracing/backgroundtab.test.ts
similarity index 84%
rename from packages/browser/test/unit/tracing/backgroundtab.test.ts
rename to packages/browser/test/tracing/backgroundtab.test.ts
index 2c998744a723..c939da8b4d03 100644
--- a/packages/browser/test/unit/tracing/backgroundtab.test.ts
+++ b/packages/browser/test/tracing/backgroundtab.test.ts
@@ -1,3 +1,9 @@
+/**
+ * @vitest-environment jsdom
+ */
+
+import { afterAll, afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+
 import { getCurrentScope } from '@sentry/core';
 import { setCurrentClient } from '@sentry/core';
 
@@ -8,8 +14,8 @@ const patchedDecoder = (!global.window.TextDecoder && (global.window.TextDecoder
 
 import { JSDOM } from 'jsdom';
 
-import { BrowserClient } from '../../../src/client';
-import { registerBackgroundTabDetection } from '../../../src/tracing/backgroundtab';
+import { BrowserClient } from '../../src/client';
+import { registerBackgroundTabDetection } from '../../src/tracing/backgroundtab';
 import { getDefaultBrowserClientOptions } from '../helper/browser-client-options';
 
 describe('registerBackgroundTabDetection', () => {
@@ -30,7 +36,7 @@ describe('registerBackgroundTabDetection', () => {
     setCurrentClient(client);
     client.init();
 
-    global.document.addEventListener = jest.fn((event, callback) => {
+    global.document.addEventListener = vi.fn((event, callback) => {
       events[event] = callback;
     });
   });
diff --git a/packages/browser/test/unit/tracing/browserTracingIntegration.test.ts b/packages/browser/test/tracing/browserTracingIntegration.test.ts
similarity index 94%
rename from packages/browser/test/unit/tracing/browserTracingIntegration.test.ts
rename to packages/browser/test/tracing/browserTracingIntegration.test.ts
index 86e46fe0ccc8..dbdebe473335 100644
--- a/packages/browser/test/unit/tracing/browserTracingIntegration.test.ts
+++ b/packages/browser/test/tracing/browserTracingIntegration.test.ts
@@ -1,3 +1,9 @@
+/**
+ * @vitest-environment jsdom
+ */
+
+import { afterAll, afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+
 import { TextDecoder, TextEncoder } from 'util';
 const oldTextEncoder = global.window.TextEncoder;
 const oldTextDecoder = global.window.TextDecoder;
@@ -25,15 +31,14 @@ import {
   startInactiveSpan,
 } from '@sentry/core';
 import type { Span, StartSpanOptions } from '@sentry/types';
-import { timestampInSeconds } from '@sentry/utils';
 import { JSDOM } from 'jsdom';
-import { BrowserClient } from '../../../src/client';
-import { WINDOW } from '../../../src/helpers';
+import { BrowserClient } from '../../src/client';
+import { WINDOW } from '../../src/helpers';
 import {
   browserTracingIntegration,
   startBrowserTracingNavigationSpan,
   startBrowserTracingPageLoadSpan,
-} from '../../../src/tracing/browserTracingIntegration';
+} from '../../src/tracing/browserTracingIntegration';
 import { getDefaultBrowserClientOptions } from '../helper/browser-client-options';
 
 // We're setting up JSDom here because the Next.js routing instrumentations requires a few things to be present on pageload:
@@ -55,6 +60,11 @@ afterAll(() => {
   Object.defineProperty(WINDOW, 'history', { value: originalGlobalHistory });
 });
 
+afterEach(() => {
+  vi.useRealTimers();
+  performance.clearMarks();
+});
+
 describe('browserTracingIntegration', () => {
   beforeEach(() => {
     getCurrentScope().clear();
@@ -226,29 +236,6 @@ describe('browserTracingIntegration', () => {
     });
   });
 
-  it("trims pageload transactions to the max duration of the transaction's children", async () => {
-    const client = new BrowserClient(
-      getDefaultBrowserClientOptions({
-        tracesSampleRate: 1,
-        integrations: [browserTracingIntegration({ idleTimeout: 10 })],
-      }),
-    );
-
-    setCurrentClient(client);
-    client.init();
-
-    const pageloadSpan = getActiveSpan();
-    const childSpan = startInactiveSpan({ name: 'pageload-child' });
-    const timestamp = timestampInSeconds();
-
-    childSpan.end(timestamp);
-
-    // Wait for 10ms for idle timeout
-    await new Promise(resolve => setTimeout(resolve, 10));
-
-    expect(spanToJSON(pageloadSpan!).timestamp).toBe(timestamp);
-  });
-
   describe('startBrowserTracingPageLoadSpan', () => {
     it('works without integration setup', () => {
       const client = new BrowserClient(
@@ -347,7 +334,7 @@ describe('browserTracingIntegration', () => {
     });
 
     it('calls before beforeStartSpan', () => {
-      const mockBeforeStartSpan = jest.fn((options: StartSpanOptions) => options);
+      const mockBeforeStartSpan = vi.fn((options: StartSpanOptions) => options);
 
       const client = new BrowserClient(
         getDefaultBrowserClientOptions({
@@ -371,7 +358,7 @@ describe('browserTracingIntegration', () => {
     });
 
     it('uses options overridden with beforeStartSpan', () => {
-      const mockBeforeStartSpan = jest.fn((options: StartSpanOptions) => ({
+      const mockBeforeStartSpan = vi.fn((options: StartSpanOptions) => ({
         ...options,
         op: 'test op',
       }));
@@ -414,7 +401,7 @@ describe('browserTracingIntegration', () => {
   });
 
   it('sets source to "custom" if name is changed in beforeStartSpan', () => {
-    const mockBeforeStartSpan = jest.fn((options: StartSpanOptions) => ({
+    const mockBeforeStartSpan = vi.fn((options: StartSpanOptions) => ({
       ...options,
       name: 'changed',
     }));
@@ -540,7 +527,7 @@ describe('browserTracingIntegration', () => {
     });
 
     it('calls before beforeStartSpan', () => {
-      const mockBeforeStartSpan = jest.fn((options: StartSpanOptions) => options);
+      const mockBeforeStartSpan = vi.fn((options: StartSpanOptions) => options);
 
       const client = new BrowserClient(
         getDefaultBrowserClientOptions({
@@ -568,7 +555,7 @@ describe('browserTracingIntegration', () => {
     });
 
     it('uses options overridden with beforeStartSpan', () => {
-      const mockBeforeStartSpan = jest.fn((options: StartSpanOptions) => ({
+      const mockBeforeStartSpan = vi.fn((options: StartSpanOptions) => ({
         ...options,
         op: 'test op',
       }));
@@ -596,7 +583,7 @@ describe('browserTracingIntegration', () => {
     });
 
     it('sets source to "custom" if name is changed in beforeStartSpan', () => {
-      const mockBeforeStartSpan = jest.fn((options: StartSpanOptions) => ({
+      const mockBeforeStartSpan = vi.fn((options: StartSpanOptions) => ({
         ...options,
         name: 'changed',
       }));
@@ -929,7 +916,7 @@ describe('browserTracingIntegration', () => {
 
   describe('idleTimeout', () => {
     it('is created by default', () => {
-      jest.useFakeTimers();
+      vi.useFakeTimers();
       const client = new BrowserClient(
         getDefaultBrowserClientOptions({
           tracesSampleRate: 1,
@@ -955,15 +942,16 @@ describe('browserTracingIntegration', () => {
       // inner1 is now ended, all good
       expect(spans).toHaveLength(1);
 
-      jest.advanceTimersByTime(TRACING_DEFAULTS.idleTimeout);
+      vi.advanceTimersByTime(TRACING_DEFAULTS.idleTimeout);
 
       // idle span itself is now ended
-      expect(spans).toHaveLength(2);
-      expect(spans[1]).toBe(idleSpan);
+      // there is also the `sentry-tracing-init` span included
+      expect(spans).toHaveLength(3);
+      expect(spans[2]).toBe(idleSpan);
     });
 
     it('can be a custom value', () => {
-      jest.useFakeTimers();
+      vi.useFakeTimers();
 
       const client = new BrowserClient(
         getDefaultBrowserClientOptions({
@@ -990,18 +978,19 @@ describe('browserTracingIntegration', () => {
       // inner1 is now ended, all good
       expect(spans).toHaveLength(1);
 
-      jest.advanceTimersByTime(2000);
+      vi.advanceTimersByTime(2000);
 
       // idle span itself is now ended
-      expect(spans).toHaveLength(2);
-      expect(spans[1]).toBe(idleSpan);
+      // there is also the `sentry-tracing-init` span included
+      expect(spans).toHaveLength(3);
+      expect(spans[2]).toBe(idleSpan);
     });
   });
 
   // TODO(lforst): I cannot manage to get this test to pass.
   /*
   it('heartbeatInterval can be a custom value', () => {
-    jest.useFakeTimers();
+    vi.useFakeTimers();
 
     const interval = 200;
 
@@ -1015,7 +1004,7 @@ describe('browserTracingIntegration', () => {
     setCurrentClient(client);
     client.init();
 
-    const mockFinish = jest.fn();
+    const mockFinish = vi.fn();
     // eslint-disable-next-line deprecation/deprecation
     const transaction = getActiveTransaction() as IdleTransaction;
     transaction.sendAutoFinishSignal();
@@ -1025,7 +1014,7 @@ describe('browserTracingIntegration', () => {
     span!.end(); // activities = 0
 
     expect(mockFinish).toHaveBeenCalledTimes(0);
-    jest.advanceTimersByTime(interval * 3);
+    vi.advanceTimersByTime(interval * 3);
     expect(mockFinish).toHaveBeenCalledTimes(1);
   });
   */
diff --git a/packages/browser/test/unit/tracing/request.test.ts b/packages/browser/test/tracing/request.test.ts
similarity index 95%
rename from packages/browser/test/unit/tracing/request.test.ts
rename to packages/browser/test/tracing/request.test.ts
index 384d62bf52e2..f1067c9e4b52 100644
--- a/packages/browser/test/unit/tracing/request.test.ts
+++ b/packages/browser/test/tracing/request.test.ts
@@ -1,13 +1,15 @@
+import { afterAll, beforeAll, beforeEach, describe, expect, it, vi } from 'vitest';
+
 import * as browserUtils from '@sentry-internal/browser-utils';
 import type { Client } from '@sentry/types';
 import * as utils from '@sentry/utils';
-import { WINDOW } from '../../../src/helpers';
+import { WINDOW } from '../../src/helpers';
 
-import { extractNetworkProtocol, instrumentOutgoingRequests, shouldAttachHeaders } from '../../../src/tracing/request';
+import { extractNetworkProtocol, instrumentOutgoingRequests, shouldAttachHeaders } from '../../src/tracing/request';
 
 beforeAll(() => {
-  // @ts-expect-error need to override global Request because it's not in the jest environment (even with an
-  // `@jest-environment jsdom` directive, for some reason)
+  // @ts-expect-error need to override global Request because it's not in the vi environment (even with an
+  // `@vi-environment jsdom` directive, for some reason)
   global.Request = {};
 });
 
@@ -15,7 +17,7 @@ class MockClient implements Partial<Client> {
   public addEventProcessor: () => void;
   constructor() {
     // Mock addEventProcessor function
-    this.addEventProcessor = jest.fn();
+    this.addEventProcessor = vi.fn();
   }
 }
 
@@ -23,13 +25,13 @@ describe('instrumentOutgoingRequests', () => {
   let client: Client;
 
   beforeEach(() => {
-    jest.clearAllMocks();
+    vi.clearAllMocks();
     client = new MockClient() as unknown as Client;
   });
 
   it('instruments fetch and xhr requests', () => {
-    const addFetchSpy = jest.spyOn(utils, 'addFetchInstrumentationHandler');
-    const addXhrSpy = jest.spyOn(browserUtils, 'addXhrInstrumentationHandler');
+    const addFetchSpy = vi.spyOn(utils, 'addFetchInstrumentationHandler');
+    const addXhrSpy = vi.spyOn(browserUtils, 'addXhrInstrumentationHandler');
 
     instrumentOutgoingRequests(client);
 
@@ -38,7 +40,7 @@ describe('instrumentOutgoingRequests', () => {
   });
 
   it('does not instrument fetch requests if traceFetch is false', () => {
-    const addFetchSpy = jest.spyOn(utils, 'addFetchInstrumentationHandler');
+    const addFetchSpy = vi.spyOn(utils, 'addFetchInstrumentationHandler');
 
     instrumentOutgoingRequests(client, { traceFetch: false });
 
@@ -46,7 +48,7 @@ describe('instrumentOutgoingRequests', () => {
   });
 
   it('does not instrument xhr requests if traceXHR is false', () => {
-    const addXhrSpy = jest.spyOn(browserUtils, 'addXhrInstrumentationHandler');
+    const addXhrSpy = vi.spyOn(browserUtils, 'addXhrInstrumentationHandler');
 
     instrumentOutgoingRequests(client, { traceXHR: false });
 
@@ -60,7 +62,7 @@ interface ProtocolInfo {
 }
 
 describe('HTTPTimings', () => {
-  describe('Extracting version from ALPN protocol', () => {
+  test('Extracting version from ALPN protocol', () => {
     const nextHopToNetworkVersion: Record<string, ProtocolInfo> = {
       'http/0.9': { name: 'http', version: '0.9' },
       'http/1.0': { name: 'http', version: '1.0' },
diff --git a/packages/browser/test/unit/transports/fetch.test.ts b/packages/browser/test/transports/fetch.test.ts
similarity index 90%
rename from packages/browser/test/unit/transports/fetch.test.ts
rename to packages/browser/test/transports/fetch.test.ts
index ae8a5d43a6e0..ccba3282251c 100644
--- a/packages/browser/test/unit/transports/fetch.test.ts
+++ b/packages/browser/test/transports/fetch.test.ts
@@ -1,8 +1,11 @@
+import type { Mock } from 'vitest';
+import { describe, expect, it, vi } from 'vitest';
+
 import type { EventEnvelope, EventItem } from '@sentry/types';
 import { createEnvelope, serializeEnvelope } from '@sentry/utils';
 
-import { makeFetchTransport } from '../../../src/transports/fetch';
-import type { BrowserTransportOptions } from '../../../src/transports/types';
+import { makeFetchTransport } from '../../src/transports/fetch';
+import type { BrowserTransportOptions } from '../../src/transports/types';
 
 const DEFAULT_FETCH_TRANSPORT_OPTIONS: BrowserTransportOptions = {
   url: 'https://sentry.io/api/42/store/?sentry_key=123&sentry_version=7',
@@ -30,7 +33,7 @@ class Headers {
 
 describe('NewFetchTransport', () => {
   it('calls fetch with the given URL', async () => {
-    const mockFetch = jest.fn(() =>
+    const mockFetch = vi.fn(() =>
       Promise.resolve({
         headers: new Headers(),
         status: 200,
@@ -53,10 +56,10 @@ describe('NewFetchTransport', () => {
 
   it('sets rate limit headers', async () => {
     const headers = {
-      get: jest.fn(),
+      get: vi.fn(),
     };
 
-    const mockFetch = jest.fn(() =>
+    const mockFetch = vi.fn(() =>
       Promise.resolve({
         headers,
         status: 200,
@@ -74,7 +77,7 @@ describe('NewFetchTransport', () => {
   });
 
   it('allows for custom options to be passed in', async () => {
-    const mockFetch = jest.fn(() =>
+    const mockFetch = vi.fn(() =>
       Promise.resolve({
         headers: new Headers(),
         status: 200,
@@ -102,7 +105,7 @@ describe('NewFetchTransport', () => {
   });
 
   it('handles when `getNativetypeof window.fetchementation` is undefined', async () => {
-    const mockFetch = jest.fn(() => undefined) as unknown as typeof window.fetch;
+    const mockFetch = vi.fn(() => undefined) as unknown as typeof window.fetch;
     const transport = makeFetchTransport(DEFAULT_FETCH_TRANSPORT_OPTIONS, mockFetch);
 
     expect(mockFetch).toHaveBeenCalledTimes(0);
@@ -111,7 +114,7 @@ describe('NewFetchTransport', () => {
   });
 
   it('correctly sets keepalive flag', async () => {
-    const mockFetch = jest.fn(() =>
+    const mockFetch = vi.fn(() =>
       Promise.resolve({
         headers: new Headers(),
         status: 200,
@@ -143,7 +146,7 @@ describe('NewFetchTransport', () => {
       expect(mockFetch).toHaveBeenNthCalledWith(i, expect.any(String), expect.objectContaining({ keepalive }));
     }
 
-    (mockFetch as jest.Mock<unknown>).mockClear();
+    (mockFetch as Mock).mockClear();
 
     // Limit resets when requests have resolved
     // Now try based on # of pending requests
diff --git a/packages/browser/test/unit/transports/offline.test.ts b/packages/browser/test/transports/offline.test.ts
similarity index 96%
rename from packages/browser/test/unit/transports/offline.test.ts
rename to packages/browser/test/transports/offline.test.ts
index ed4cd770101d..a8352cb4102d 100644
--- a/packages/browser/test/unit/transports/offline.test.ts
+++ b/packages/browser/test/transports/offline.test.ts
@@ -1,3 +1,5 @@
+import { describe, expect, it } from 'vitest';
+
 import 'fake-indexeddb/auto';
 
 import { TextDecoder, TextEncoder } from 'util';
@@ -10,8 +12,9 @@ import type {
 } from '@sentry/types';
 import { createEnvelope } from '@sentry/utils';
 
-import { MIN_DELAY } from '../../../../core/src/transports/offline';
-import { createStore, makeBrowserOfflineTransport, push, shift, unshift } from '../../../src/transports/offline';
+import { createStore, makeBrowserOfflineTransport, push, shift, unshift } from '../../src/transports/offline';
+
+const MIN_DELAY = 100;
 
 function deleteDatabase(name: string): Promise<void> {
   return new Promise<void>((resolve, reject) => {
diff --git a/packages/browser/test/unit/userfeedback.test.ts b/packages/browser/test/userfeedback.test.ts
similarity index 92%
rename from packages/browser/test/unit/userfeedback.test.ts
rename to packages/browser/test/userfeedback.test.ts
index cb498cac7893..93a8de33690b 100644
--- a/packages/browser/test/unit/userfeedback.test.ts
+++ b/packages/browser/test/userfeedback.test.ts
@@ -1,4 +1,6 @@
-import { createUserFeedbackEnvelope } from '../../src/userfeedback';
+import { describe, expect, test } from 'vitest';
+
+import { createUserFeedbackEnvelope } from '../src/userfeedback';
 
 describe('userFeedback', () => {
   test('creates user feedback envelope header', () => {
diff --git a/packages/browser/test/unit/utils/lazyLoadIntegration.test.ts b/packages/browser/test/utils/lazyLoadIntegration.test.ts
similarity index 92%
rename from packages/browser/test/unit/utils/lazyLoadIntegration.test.ts
rename to packages/browser/test/utils/lazyLoadIntegration.test.ts
index fa6bc62fb4fd..ec88ae49a1a9 100644
--- a/packages/browser/test/unit/utils/lazyLoadIntegration.test.ts
+++ b/packages/browser/test/utils/lazyLoadIntegration.test.ts
@@ -1,6 +1,12 @@
+/**
+ * @vitest-environment jsdom
+ */
+
+import { afterAll, afterEach, beforeEach, describe, expect, test } from 'vitest';
+
 import { TextDecoder, TextEncoder } from 'util';
-import { SDK_VERSION, lazyLoadIntegration } from '../../../src';
-import * as Sentry from '../../../src';
+import { SDK_VERSION, lazyLoadIntegration } from '../../src';
+import * as Sentry from '../../src';
 const patchedEncoder = (!global.window.TextEncoder && (global.window.TextEncoder = TextEncoder)) || true;
 // @ts-expect-error patch the encoder on the window, else importing JSDOM fails (deleted in afterAll)
 const patchedDecoder = (!global.window.TextDecoder && (global.window.TextDecoder = TextDecoder)) || true;
diff --git a/packages/browser/tsconfig.test.json b/packages/browser/tsconfig.test.json
index 9bdd2aa76dab..00cada2d8bcf 100644
--- a/packages/browser/tsconfig.test.json
+++ b/packages/browser/tsconfig.test.json
@@ -1,13 +1,9 @@
 {
   "extends": "./tsconfig.json",
 
-  "include": ["test/**/*"],
-  "exclude": ["test/integration/**/*"],
+  "include": ["test/**/*", "vite.config.ts"],
 
   "compilerOptions": {
-    // should include all types from `./tsconfig.json` plus types for all test frameworks used
-    "types": ["node", "jest"]
-
     // other package-specific, test-specific options
   }
 }
diff --git a/packages/browser/vite.config.ts b/packages/browser/vite.config.ts
new file mode 100644
index 000000000000..a5523c61f601
--- /dev/null
+++ b/packages/browser/vite.config.ts
@@ -0,0 +1,10 @@
+import { defineConfig } from 'vitest/config';
+
+import baseConfig from '../../vite/vite.config';
+
+export default defineConfig({
+  ...baseConfig,
+  test: {
+    ...baseConfig.test,
+  },
+});