Google Tag Manager 404 error (gtm.js 404)

So you’ve added a Google Tag Manager snippet to a website (by carefully following the instructions). Website’s developer contacts you and says that Google Tag Manager snippet generates errors (gtm.js 404) and keeps littering his error log. Well, there’s a simple solution for this issue.

An error in Javascript console you are seeing should look like this (replace GTM-XXXXX with your Google Tag Manager’s Container ID):

The solution to gtm.js 404 error

The problem lies within Google Tag Manager itself. Your browser is requesting data from Google’s servers although that container is still not published yet, thus no data will be returned. The solution here is to publish Google Tag Manager container once you create it.

Always complete the following actions when you plan tracking of the new website with GTM:

• Create a new container in GTM.
• Publish it (with default settings).
• Install GTM to your website according to instructions (or ask a developer to do it).
• Open your website in a browser and check Javascript Console (if you’re not familiar with it, here are short Chrome, Firefox and Internet Explorer instructions).
• If there’s no gtm.js 404 error – go ahead and start setting up your marketing tags.

This isn’t a big problem, but if your developers are tracking Javascript errors with particular tools (e.g. TrackJS), they’ll see those 404 errors in reports. This will create an unwanted noise for them (yes, I know they can use filters, but simply publishing an empty container won’t hurt anybody).

Conclusion

Every time you set up a new Google Tag Manager container, publish it (even though it’s totally empty), otherwise, the response from Google will return 404 not found error. This isn’t a critical error but might cause a little mess in developers’ error logs. This is a common rookie mistake which is a #2 on my list of most common Google Tag Manager mistakes. Make sure you check the full list.

If you have any other questions related to Google Tag Manager, feel free to post a comment or contact me via social media accounts. Also, consider subscribing to my newsletter for more relevant GTM or Google Analytics tips and guides.