How can I use Google Analytics to find 404 pages?

Question

I am trying to use Google Analytics to find 404 pages using the following set of instructions:

To begin, go to Google Analytics and then navigate to Customization » Custom Reports. Now click on + New Custom Report.

Next, you’ll have to give a name to your report, like Broken Links Report. And then enter the following settings:

• Change the Type to Flat Table
• For Dimensions, add Landing Page and then Full Referrer
• For Metrics, search and add Entrances
• Then in the Filters, click add filter and select Page Title (make sure the first dropdown is set to Include and the next is set to Exact)
• Enter the exact title of your broken link, such as Page not found or 404.html
• Select All views associated with this account under Views
• Click Save when you’re done

Source

However, the report is always empty (there is no data for this view) for whatever time range, though I know there were some 404 pages during this period.

Can you tell me what might be wrong with this method or how else I can accomplish this?

I also checked Using analytics to find what pages brought users to a 404 and it seems that the OP is using a similar method to find 404 pages.

Update

My site uses WP Rocket and I check the 404 page and find the following code:

<script async src="https://www.googletagmanager.com/gtag/js?id=UA-xxxxx-xxx"></script>
<script>
        window.dataLayer = window.dataLayer || [];
        function gtag(){dataLayer.push(arguments);}
        gtag('js', new Date());
        gtag('config', 'UA-xxxxx-xxx');
        gtag('config', 'AW-xxxxxxxx');
      </script>

Not sure if that will affect the Google Analysics report.

Answer 1

If you go to "Behavior" and "Content" you can filter for 404 in the title or URL. Once you have that page you can save it as a report and have it emailed every day, week, or month.