Any website will have significant inbound traffic (2-3%) which lands on non-existent pages generating 404 Not Found errors. This happens for many reasons, from Digital Media Campaign long tails, referring articles, document links or just human error.
Create a custom Report
To create a custom report in Google Analytics, look at your Not Found Page. You can add rubbish to the URL, for example “https://canepa.net/rubbish“. You will have some form of “Not Found” text in your page title on the 404 error.
In Analytics go to Behavior>Site Content>All Pages, select the “Page Title” Dimension and search for your not found string.
Add the “page” secondary dimension, et voilà! You will have the list of you 404 (Not Found) pages.
You can easily build the same report in other platforms like Adobe Analytics or Open Web Analytics. Just apply the same criteria. Analyze each not found page and either fix it. Otherwise redirect it to the most similar content (either with a 301 – Moved permanently or a 302 – Moved temporarily, if you intend to address the not found by developing a new page and then change the redirect to 301 once the page is online). Share the report daily to yourself and the editorial team. Lean more about HTTPD return codes at the W3C website.
404 Not Found Errors and SEO
Google doesn’t damage your website ranking because of 404 Not Found errors:
404s are a perfectly normal part of the web; the Internet is always changing, new content is born, old content dies, and when it dies it (ideally) returns a 404 HTTP response code. Search engines are aware of this; we have 404 errors on our own sites, as you can see above, and we find them all over the web. In fact, we actually prefer that, when you get rid of a page on your site, you make sure that it returns a proper 404 or 410 response code (rather than a “soft 404”). Keep in mind that in order for our crawler to see the HTTP response code of a URL, it has to be able to crawl that URL—if the URL is blocked by your robots.txt file we won’t be able to crawl it and see its response code. The fact that some URLs on your site no longer exist / return 404s does not affect how your site’s other URLs (the ones that return 200 (Successful)) perform in our search results.from https://developers.google.com/search/blog/2011/05/do-404s-hurt-my-site
404 Errors should be monitored and managed because you probably have relevant content that will help maintain SEO and traffic.
Instruct you team never to unpublish or delete content but redirect it as needed and always leverage the report.
You should also use the percentage of 404 Not Found Errors as a KPI and in the short term this should be a KPI to bring close to zero.
In the long term this is something to always keep an eye on. You will have a free traffic boost, better experience for your customers who will land on relevant content. Hopefully they never see annoying 404 Not Found messages again!
You can find other articles on these topics here.