How To Track 404 Errors With Google Analytics and Google Tag Manager

Let’s admit it – 404 errors suck. From both visitor’s and website owner’s perspective. As a website owner, you don’t want your visitors to appear in a dead end. It hurts your brand, your conversions, and in some cases your search engine optimization efforts. But that shouldn’t be a problem anymore, because in this blog post I’ll show you how to track 404 errors with Google Analytics + Google Tag Manager, and act accordingly (of course!).

The Premise

404 is an error message displayed by a browser indicating that an Internet address cannot be found.

Why is it bad? Mainly, it might hurt your conversions. Imagine that a person is looking for particular information and you have that topic covered on your website. But when he/she clicks the link – no luck.

In most cases that might result in a bounce or even worse – the visitor might jump over to your competitor’s website and (possibly) make a purchase there.

Just For Giggles

In fact, did not plan to post this example at all, but it’s too hilarious.

Anyway, I was looking for some blog post/guide to back my arguments about why 404 errors are important to monitor and why they might hurt your business. So I did a quick search and stumbled upon siteimprove.com blog post “What Broken Links Cost Your Business” in Google search.

Guess what? After I clicked the link, I got 404 error. Oh, the irony! What do broken links cost your business? I don’t know… a bounce, I guess.

A simple 301 redirect could have solved this issue.

What Should You Do?

There are two steps that need to be addressed:

1. You need to monitor 404 errors (that’s my main focus in this blog post).
2. You need to fix those broken links by redirecting people to a new destination URL (I’ll cover some general tactics and tools without diving deeper into details).

How Can You Track 404 Errors?

I’d like to point out several options:

1. Track 404 errors with Google Search Console (GSC) offers a report of site errors (including 404s) that were spotted by Google’s crawlers. Joe Robinson at Moz has posted an in-depth guide how you can monitor and fix errors with GSC, I recommend reading it.
   However, there are some limitations: those errors are logged by the Googlebot crawler (not necessarily viewed by users), so you can’t see how it affects users’ overall sessions, and you can’t include it in your analytics reporting.
2. Track 404 errors with Google Analytics behavior reports. Another option which also does not require any additional development is checking GA All Pages report. I’ll explain it in the further chapter of this blog post.
3. Track 404 errors with Google Analytics events via Google Tag manager. Main focus of this blog post is dedicated to this option. Continue reading.

Track 404 Errors With Google Analytics – Without Additional Development

Is there a 404 page on your website? You can easily check that by adding some non-sense in the URL. For example, https://www.example.com/post/nonsense.

If you see a “Page not found” message, that’s a good start. Here’s mine:

Next, check the title of that 404 page. Mine is Page not found – Analytics Mania.

So all we need to do is to apply a custom filter to Behavior > Site Content > All Pages report in Google Analytics where we will see how many people (and how many times) have seen 404 error.

Open your Google Analytics account and head over to Behavior > Site Content > All Pages.

Now’ you’ll need to create an advanced filter which displays traffic only to those pages of which title contains “Page not found”.

1. Add Page Title as a secondary dimension.
2. Then click Advanced link next to the search field.
3. Then choose rule Page title contains Page not found. Remember, your 404 error page might contain another title. I used “Page not found” as an example, because that’s a title of error page on my blog.

That’s it! Now you have a report of how many people ended up in 404 page, how many bounced of them, etc.

TRACK 404 ERRORS WITH GOOGLE ANALYTICS and GTM

Another way to approach this issue is to fire a Google Analytics event when a visitor encounters a 404 error. The most recommended way to fire “404” event is to utilize Google Tag Manager.

First, we’ll need to check whether a page view is actually a 404 error. Then we’ll trigger a Universal Analytics event and send the corresponding data to Google Analytics.

New Variable And Trigger

As I have previously mentioned, one of the easiest ways to distinguish a 404 page from a regular page in your analytics reports is page title.

I actually still cannot believe that this variable (Page title) isn’t among default variables in GTM. That’s why we need to create a user-defined variable in Google Tag Manager Page Title.

In order to do so, log in to your Google Tag Manager account, go to Variables and create a new one with the following settings:

• Title – Javascript – Page Title
• Type – Javascript
• Global variable name – document.title

This variable will return a value of page title that a visitor is currently on.

After that, we should to create a trigger which fires when Page title contains “Page not found”. In your case the title might be different, so use what’s best suited for your website.

In your Google Tag Manager account, go to Triggers and create a trigger with the following settings:

Important – this trigger is case sensitive. So if your 404 page title is Page Not Found, then Page not found trigger will not work because Not Found ≠ not found.

Or you can simply use this trigger condition instead:

Let’s send 404 Errors as Events to Google Analytics

In Google Tag Manager, go to Tags and create new tag:

• Title – GA Event – 404 Error
• Type – Universal Analytics
• Enter Tracking ID (if you still don’t do it, I highly recommend adding Google Analytics Tracking ID as a constant variable. This will save you a lot of time and hassle in the long run).
• Track Type – Event
• Event Category – 404 error
• Event Action – {{Page URL}}. Every time this even is fired, Google Tag Manager will dynamically fill in Page URL (full web address) as event action. This way you’ll see which URLs get the most 404 error hits.
  You can also use {{Page Path}} instead of {{Page URL}}, if you wish. If your web project spans across multiple domains and all data is visible in one Google Analytics account, then you should definitely stick with {{Page URL}} as event action.
• No-interaction hit – true
• Link previously created trigger Pageview – 404 Error to this Universal Analytics tag.

Hit Save, enable Preview & Debug mode and test whether the tag fires ONLY when it’s supposed to. If Preview and debug mode does not work for you, take a look at 10 ways to fix P&D mode in Google Tag Manager. If your newly created tag does not fire when it should, read this blog post – most common Google Tag Manager mistakes.

Leverage Google Analytics real-time reports: enter a gibberish URL that really does not exist on your website and open GA real-time Events report. If a 404 event appears there within seconds – you’re good to go!

OK, Now What?

Once you’ve started tracking 404 errors with Google Analytics (or without), you can now earn more about how visitors interact with the website. Also, find out which pages are actually dead ends.

Usually 404 errors are “born” when page URLs change, e.g. you edited a web address in order to add relevant keywords for SEO. If that page was already indexed by Google, new visitors from search results will be redirected to the old address of a non-existing page.

So whenever you change the URL, ALWAYS create a 301 redirect (a.k.a. moved permanently) from old URL to a new one. If you’re using WordPress Plugin Redirection, you can easily do that right from your WP admin panel.

Also, this WP plugin automatically tracks 404 errors which you can turn into 301 redirects right away.

Why 301 redirect is so important? Because Google honors this setting: it understands that resource X is not available anymore under the old URL and is now moved to another web address. This way the accumulated reputation is transferred from the old address to the new one.

Conclusion

In this blog post I have described two ways how you can track 404 errors with Google Analytics. The first option does not require any development – you can achieve the result just by using advanced search. The second one is to utilize Google Tag Manager and send 404 errors as events to Google Analytics.

These are not the only options available. I also briefly mentioned Google Search Console’s error reports (but those apply to Googlebot’s 404 errors rather than actual visitors).

Another options that was skipped in this blog post – asking a developer to fire a dataLayer event whenever a 404 error occurs (and then transfer that data with GTM to GA). But I ignored this option on purpose (this time), because I wanted to focus on possibilities that can be achieved without coding.

If you know more ways how to track 404 errors with Google Analytics (because there definitely are some), let me know in the comments!