Question

I’d like to catch all client-side JavaScript errors on our site and log them. What are some best practices for doing this?

Thoughts:

• I can easily add a /log/ handler to our webapp, parse GET/POST parameters and use our existing logging system on the server-side. Is that too obvious?
• Does window.onerror work everywhere? What if an error occurs in the handler?
• Should I attach an <img> tag to the page or make an XmlHttpRequest? What if the XHR fails?
• What about broken images and jQuery Ajax failures — can I catch those too?

Answer 1

All suggestions made by Jbecwar and dgvid are cool, I would add:

• note that Opera does not support error event see quirksmode error event
• gathering stacktraces with stacktrace.js could help troubleshoot errors
• if error handler is unable to send error report to server side, fallback to using cookies: set cookie for errors.yourdomain.com with base64 encoded error report (compressed?) and request empty 1×1 pixel image from that domain on every page
• or use HTML5 local storage and upload it when you can