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Replacement for JavaScript Errors Notifier (Chrome Extension)

Heads up about the JavaScript Errors Notifier extension for Google Chrome. Looks like it was removed from the Chrome store sometime last year. Not sure of the reason behind it, but can tell you that currently there are no suitable extensions to replace it. Kinda sucks because JavaScript Errors Notifier was one of my favorite “always on” extensions. It makes it easy to spot any JavaScript errors as you develop, design, or browse the Web. Fortunately there’s still a way to use this extremely useful extension..

Update! Good news, JavaScript Errors Notifier is back in the Chrome store. For all the gory drama that led us here, check out this thread. Also, you can find some updates from the developer in the comments below. Cheers and thanks to the developer, please keep it going. This is a very important, useful extension.

For those not familiar, here is a quick screenshot that shows how it works:

JavaScript Errors Notifier showing errors on a website (click to view full-size image)

Notice the little red icon next to the browser’s address bar. If the current web page does not have any JavaScript errors, it is greyed out. If the page does have any errors, the little icon displays red. Then if you click on the icon, it pops up a little dialogue with specific details about each error. Again, super useful for web developers and anyone who wants to keep an eye on things.

No suitable alternatives (yet)

I’m hoping that this post will bring attention and “inspire” someone to pick up development or fork the JavaScript Errors Notifier addon. Currently there are no suitable alternatives for Chrome. So it falls into the “one of a kind” and “virtually priceless” categories.

To be fair, there are a couple of other “JavaScript notifier” type plugins available for Chrome, but they don’t really inspire a lot of confidence:

You can check those out if you’re feeling brave, but for me there’s too many red flags to take seriously. The original, now-removed JavaScript Errors Notifier extension had many, many users, and many great reviews.

Firefox? JavaScript Errors Notifier add-on is still available for Firefox :)

So what to do? As a web developer, I can use the browser’s code inspector to really dig in and examine JavaScript (and other) errors on any web page. BUT as a regular human just browsing the Web, there is no way to monitor JS errors “as you surf”. I manage many web pages, and surfing around pages is one way that I keep an eye on things, catch errors, and so forth. Thanks to the JavaScript Errors Notifier extension, I’ve caught a lot of errors that otherwise would have been missed.

The good news? JavaScript Errors Notifier is still available on GitHub :)

Replace with unpacked extension

JavaScript Errors Notifier is developed by Sergey Barbushin. It’s currently available as a free Firefox add-on. For Chrome, the extension was available for several years at the Chrome Web Store via the following URL:


That’s now a 404 Not Found, sadly. The good news is that the source code for the extension remains available at GitHub. So for now at least, it’s still possible to run JavaScript Errors Notifier as an “unpacked” extension. This may change in the future, but for now it works great. Here’s how to set it up in a couple of minutes:

  1. Download the extension (ZIP file) via GitHub
  2. Unzip the file to get the extension folder, /javascript-errors-notifier/
  3. Move the folder to a permanent location (e.g., /Applications/ on macOS)
  4. Open Chrome browser, in the address bar visit chrome://extensions/
  5. Click to toggle “Developer mode” (upper-right corner)
  6. Click “Load unpacked” from the top menu buttons
  7. Choose the extension folder, /javascript-errors-notifier/
  8. Click “Select” and done.

After selecting the folder, it immediately will appear among your other extensions:

JavaScript Errors Notifier running locally (click to view full-size image)

I’ve been running the extension this way for a couple of weeks and it’s working beautifully. A few notes to keep in mind:

  • The extension will break if you move the folder after install
  • After installing, you can check for errors by clicking the “Errors” button
  • At this time, there is only one error: “Manifest version 2 is deprecated, and support will be removed in 2023.” Not a huge deal really.

Hopefully, the extension author will jump back in and continue development. If not, then eventually it will no longer work, have bugs, etc. But for right now, running the extension locally/unpacked works great. Maybe it will buy enough time for some alternate JavaScript-notifier extensions to hit the scene.

A lot of people use this extension, so hopefully someone will pick it up, fork, or whatever is needed to keep it alive and awesome.

Keep me posted If you know of any alternative for JavaScript Errors Notifier, or if you know of any new developments with the original version, please let me know so I can update this article. Thanks!

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10 responses to “Replacement for JavaScript Errors Notifier (Chrome Extension)”

  1. Jim S. Smith 2022/04/14 12:52 pmReply


    As usual,

    Seems that many of these “big projects” are doing away with a lot of useful features that many developers make heavy use of! Such a shame that they make all these radical decisions, without actually seeing how much of their user-base may use these features.

    My biggest complaint about FireFox – was just THIS sort of behavior. They removed so many useful features that I used quite frequently like: Viewing the contents of cookies, being able to import my crafted search-engine plugin XML files (for testing before submission), backing up search-engine plugins (a BIG ouch when removed), and several other features!

    I don’t expect GOOGLE, MOZILLA, and other “big projects” to cease this one-sided decision-making anytime soon, either.

    This is exactly one of the major reasons why there are many alternative projects cropping up everywhere, to include an alternate to WordPress. I LOT of people are very upset that WordPress is forcing “Gutenberg editor” upon everyone – and increasing the serious “codebase bloat” in the process.

    It’s only going to get worse, I’m afraid – as the “big-company mentality” sets in for the long haul. We, the users, are just “numbers” and nothing more.

    Always happy to see workable alternatives presented, though.

    – Jim S.

  2. I was doing research on a JS notifier chrome extensions and stumbled on this post.

    I ended up using the mentioned extension.

    Keep up the good work Jeff.

  3. Andrew Chepry 2022/12/12 3:29 pmReply

    Thank you so much for this workaround! JavaScript Errors Notifier was for years (and still is thanks to you) on the top of my must-have extensions for Chrome!

  4. Coinzdude 2023/02/07 1:22 pmReply

    I just resubmitted this to the chrome store. Hopefully it goes through.

  5. Waiting for the submission answer ;-)

  6. Also, I noticed while working on this project at some point, I was no longer able to manually install the legacy Manifest V2 version of the extension. It seems chromium could now be blocking legacy extensions as well.

  7. It seems the Chrome Store has some longer delays for extension updates. I made an initial publish attempt with something that simply runs, just to see what issues there would be to publish. After it went live, I published a more fully working version and am still waiting for it to launch. I’ll update here when a much better working version is live.

  8. Working update is live! Please submit feedback to https://github.com/coinzdude/javascript-errors-notifier/tree/manifest-v3 (I need to break off the fork before issues can be directly submitted)

  9. Another update, 4.04 beta is live on github and pushed to the chrome store (currently, taking about 3 days to go live). The latest allows you to specify domains to apply filtering. Uncheck “show icon on all sites” and then specify the domains you want to be active.

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