diff --git a/.github/workflows/linkcheck.yml b/.github/workflows/linkcheck.yml
new file mode 100644
index 000000000000..abafc668c818
--- /dev/null
+++ b/.github/workflows/linkcheck.yml
@@ -0,0 +1,42 @@
+# .github/workflows/run-htmltest.yml
+# (c) 2021 Robb Romans
+#
+# Run htmltest link checker on generated HTML output in dist/
+# https://github.com/wjdp/htmltest
+#
+name: run-htmltest
+concurrency:
+  group: pullrequest-untrusted-htmltest-${{ github.event.number }}
+  cancel-in-progress: true
+on: pull_request
+jobs:
+  htmltest:
+    runs-on: ubuntu-large
+    container:
+       image: ghcr.io/cirruslabs/flutter:latest
+    steps:
+      - name: Checkout Code
+        uses: actions/checkout@v4
+      - name: Setup Go
+        uses: actions/setup-go@v3
+        with:
+          go-version: stable
+          cache: true
+      - name: Install doc2go
+        run: go install go.abhg.dev/doc2go@latest
+      - name: Generate API reference
+        run: doc2go -out www ./...
+      - name: Test HTML
+        # https://github.com/wjdp/htmltest-action/
+        # Don't fail the build on broken links
+        continue-on-error: false
+        uses: wjdp/htmltest-action@master
+        with:
+          config: .htmltest.yml
+      - name: Archive htmltest results
+        uses: actions/upload-artifact@v3
+        # Note: Set ACTIONS_RUNTIME_TOKEN env variable to test with nektos/act
+        with:
+          name: htmltest-report
+          path: tmp/.htmltest/htmltest.log
+          retention-days: 7 # Default is 90 days
\ No newline at end of file
diff --git a/.htmltest.yml b/.htmltest.yml
new file mode 100644
index 000000000000..f2c6fd3f2b55
--- /dev/null
+++ b/.htmltest.yml
@@ -0,0 +1,17 @@
+DirectoryPath: "www"
+EnforceHTTPS: true
+IgnoreEmptyHref: true
+IgnoreInternalEmptyHash: true
+IgnoreDirectoryMissingTrailingSlash: false
+IgnoreURLs:
+  - "app.viam.com"
+  - "fonts.gstatic.com"
+  - "contributor-covenant.org"
+IgnoreDirs:
+  - "lib"
+CacheExpires: "6h"
+# IgnoreDirs: - if we need to ever ignore files
+CheckInternal: false
+CheckDoctype: false
+CheckScripts: false
+FileExtension: ".html"
diff --git a/spatialmath/rotationMatrix.go b/spatialmath/rotationMatrix.go
index 53453d9d6f60..1f9363050080 100644
--- a/spatialmath/rotationMatrix.go
+++ b/spatialmath/rotationMatrix.go
@@ -38,7 +38,7 @@ func (rm *RotationMatrix) AxisAngles() *R4AA {
 }
 
 // Quaternion returns orientation in quaternion representation.
-// reference: http://www.euclideanspace.com/maths/geometry/rotations/conversions/matrixToQuaternion/index.htm
+// reference: https://www.euclideanspace.com/maths/geometry/rotations/conversions/matrixToQuaternion/index.htm
 func (rm *RotationMatrix) Quaternion() quat.Number {
 	var q quat.Number
 	m := rm.mat
diff --git a/spatialmath/rotationMatrix_test.go b/spatialmath/rotationMatrix_test.go
index d8d7c2823c41..67e26c98121b 100644
--- a/spatialmath/rotationMatrix_test.go
+++ b/spatialmath/rotationMatrix_test.go
@@ -11,7 +11,7 @@ import (
 
 func TestQuaternionConversion(t *testing.T) {
 	// Test that conversion to rotation matrix to quaternion is correct
-	// http://www.euclideanspace.com/maths/geometry/rotations/conversions/matrixToQuaternion/examples/index.htm
+	// https://www.euclideanspace.com/maths/geometry/rotations/conversions/matrixToQuaternion/examples/index.htm
 	cos45 := 0.7071067811865476
 	cases := []struct {
 		input    [9]float64