diff --git a/README.md b/README.md
index e01b8f9..b8f46e0 100644
--- a/README.md
+++ b/README.md
@@ -165,7 +165,11 @@ The `initProgressBar` function takes an optional object of options. The followin
 | resultElement | Override the *element* used for the result. If specified, resultElementId will be ignored. | document.getElementById(resultElementId) |
 | onProgress | function to call when progress is updated | CeleryProgressBar.onProgressDefault |
 | onSuccess | function to call when progress successfully completes | CeleryProgressBar.onSuccessDefault |
-| onError | function to call when progress completes with an error | CeleryProgressBar.onErrorDefault |
+| onError | function to call on a known error with no specified handler | CeleryProgressBar.onErrorDefault |
+| onTaskError | function to call when progress completes with an error | onError |
+| onNetworkError | function to call on a network error (ignored by WebSocket) | onError |
+| onHttpError | function to call on a non-200 response (ignored by WebSocket) | onError |
+| onDataError | function to call on a 200 response that's not JSON or has invalid schema due to a programming error (ignored by WebSocket) | onError |
 | onResult | function to call when returned non empty result | CeleryProgressBar.onResultDefault |
 
 
diff --git a/celery_progress/static/celery_progress/celery_progress.js b/celery_progress/static/celery_progress/celery_progress.js
index 85dbb44..e0a58d9 100644
--- a/celery_progress/static/celery_progress/celery_progress.js
+++ b/celery_progress/static/celery_progress/celery_progress.js
@@ -10,7 +10,11 @@ var CeleryProgressBar = (function () {
         }
     }
 
-    function onErrorDefault(progressBarElement, progressBarMessageElement, excMessage) {
+    /**
+     * Default handler for all errors.
+     * @param data - A Response object for HTTP errors, undefined for other errors
+     */
+    function onErrorDefault(progressBarElement, progressBarMessageElement, excMessage, data) {
         progressBarElement.style.backgroundColor = '#dc4f63';
         progressBarMessageElement.innerHTML = "Uh-Oh, something went wrong! " + excMessage;
     }
@@ -22,7 +26,7 @@ var CeleryProgressBar = (function () {
         progressBarMessageElement.innerHTML = progress.current + ' of ' + progress.total + ' processed. ' + description;
     }
 
-    function updateProgress (progressUrl, options) {
+    async function updateProgress (progressUrl, options) {
         options = options || {};
         var progressBarId = options.progressBarId || 'progress-bar';
         var progressBarMessage = options.progressBarMessageId || 'progress-bar-message';
@@ -31,31 +35,53 @@ var CeleryProgressBar = (function () {
         var onProgress = options.onProgress || onProgressDefault;
         var onSuccess = options.onSuccess || onSuccessDefault;
         var onError = options.onError || onErrorDefault;
+        var onTaskError = options.onTaskError || onError;
+        var onNetworkError = options.onNetworkError || onError;
+        var onHttpError = options.onHttpError || onError;
+        var onDataError = options.onDataError || onError;
         var pollInterval = options.pollInterval || 500;
         var resultElementId = options.resultElementId || 'celery-result';
         var resultElement = options.resultElement || document.getElementById(resultElementId);
         var onResult = options.onResult || onResultDefault;
 
 
-        fetch(progressUrl).then(function(response) {
-            response.json().then(function(data) {
-                if (data.progress) {
-                    onProgress(progressBarElement, progressBarMessageElement, data.progress);
-                }
-                if (!data.complete) {
-                    setTimeout(updateProgress, pollInterval, progressUrl, options);
+        let response;
+        try {
+            response = await fetch(progressUrl);
+        } catch (networkError) {
+            onNetworkError(progressBarElement, progressBarMessageElement, "Network Error");
+            throw networkError;
+        }
+
+        if (response.status === 200) {
+            let data;
+            try {
+                data = await response.json();
+            } catch (parsingError) {
+                onDataError(progressBarElement, progressBarMessageElement, "Parsing Error")
+                throw parsingError;
+            }
+
+            if (data.progress) {
+                onProgress(progressBarElement, progressBarMessageElement, data.progress);
+            }
+            if (data.complete === false) {
+                setTimeout(updateProgress, pollInterval, progressUrl, options);
+            } else {
+                if (data.success === true) {
+                    onSuccess(progressBarElement, progressBarMessageElement, data.result);
+                } else if (data.success === false) {
+                    onTaskError(progressBarElement, progressBarMessageElement, data.result);
                 } else {
-                    if (data.success) {
-                        onSuccess(progressBarElement, progressBarMessageElement, data.result);
-                    } else {
-                        onError(progressBarElement, progressBarMessageElement, data.result);
-                    }
-                    if (data.result) {
-                        onResult(resultElement, data.result);
-                    }
+                    onDataError(progressBarElement, progressBarMessageElement, "Data Error");
+                }
+                if (data.hasOwnProperty('result')) {
+                    onResult(resultElement, data.result);
                 }
-            });
-        });
+            }
+        } else {
+            onHttpError(progressBarElement, progressBarMessageElement, "HTTP Code " + response.status, response);
+        }
     }
     return {
         onSuccessDefault: onSuccessDefault,
diff --git a/celery_progress/static/celery_progress/websockets.js b/celery_progress/static/celery_progress/websockets.js
index e136b03..6dfb78f 100644
--- a/celery_progress/static/celery_progress/websockets.js
+++ b/celery_progress/static/celery_progress/websockets.js
@@ -7,8 +7,8 @@ var CeleryWebSocketProgressBar = (function () {
         CeleryProgressBar.onResultDefault(resultElement, result);
     }
 
-    function onErrorDefault(progressBarElement, progressBarMessageElement, excMessage) {
-        CeleryProgressBar.onErrorDefault(progressBarElement, progressBarMessageElement, excMessage);
+    function onErrorDefault(progressBarElement, progressBarMessageElement, excMessage, data) {
+        CeleryProgressBar.onErrorDefault(progressBarElement, progressBarMessageElement, excMessage, data);
     }
 
     function onProgressDefault(progressBarElement, progressBarMessageElement, progress) {
@@ -24,6 +24,7 @@ var CeleryWebSocketProgressBar = (function () {
         var onProgress = options.onProgress || onProgressDefault;
         var onSuccess = options.onSuccess || onSuccessDefault;
         var onError = options.onError || onErrorDefault;
+        var onTaskError = options.onTaskError || onError;
         var resultElementId = options.resultElementId || 'celery-result';
         var resultElement = options.resultElement || document.getElementById(resultElementId);
         var onResult = options.onResult || onResultDefault;
@@ -45,9 +46,9 @@ var CeleryWebSocketProgressBar = (function () {
                 if (data.success) {
                     onSuccess(progressBarElement, progressBarMessageElement, data.result);
                 } else {
-                    onError(progressBarElement, progressBarMessageElement, data.result);
+                    onTaskError(progressBarElement, progressBarMessageElement, data.result);
                 }
-                if (data.result) {
+                if (data.hasOwnProperty('result')) {
                     onResult(resultElement, data.result);
                 }
                 ProgressSocket.close();