In the latest episodes of Google’s SEO Snippets video series, John Mueller answers a webmaster’s question regarding 404 errors.
Specifically, the site owner was wondering if 404 errors are a cause for concern when they exist within old versions of a site.
“What should I do with 404s in Search Console that are from ancient versions of my site?”
Mueller briefly explains why 404 errors occur in the first place, and suggests the common SEO best practice of setting up redirects to relevant pages. However, even with redirects in place, 404 errors may still pop up in Search Console.
Site owners may decide to drop redirects because of the overhead costs involved with maintaining them, or they might just forget about the directs being in place. Whatever the case may be, there are now 404s showing up for old sections of a site.
Is this a problem? Well, it depends on how old these parts of the site are. If they’re so old that they’re no longer being linked to internally, and not receiving any traffic, then that’s “perfectly fine.”
If the URLs returning 404 errors are being linked to from other pages of the site, and/or receiving traffic, then they should be dealt with by setting up redirects.
That solution may be easy enough for a handful of URLs, but what if there are many 404 errors showing up? Mueller suggests relying on Search Console’s assessment of the crawl errors.
Google Search Console will sort crawl errors in order of priority. If Search Console determines that all top crawl errors are irrelevant, then it is not necessary to set up redirects.
For Mueller’s full response, see the video and transcription below.
“In your server logs, or analytics, check for traffic to those URLs. If there’s no traffic, that’s great. In Search Console check for links to those URLs. Are there no relevant links? That’s great too. If you see nothing special in either the links, or the traffic, having those pages return 404 is perfectly fine.
If you do see traffic to those URLs, or see links pointing at those URLs, check where they’re coming from and have those links point at the new URLs instead. Or, if it looks like a lot of traffic or links are going to those URLs, perhaps putting a redirect back in place would be more efficient.
That works for a few crawl errors, but what if you have a ton of 404 errors? Search Console makes this easy; it prioritizes crawl errors for you. If the top errors in the report are all irrelevant you can rest assure there is nothing more important further down on the list. Crawl errors for 404s that you don’t want to have indexed don’t negatively effect the rest of your site in search. So take your time to find a good approach that works for you.”