In the latest episode of the Search Off The Record podcast, Google engineer Gary Illyes reported that “soft” 404 errors are wasting crawl budget.
At the same time, he clarified that 404 and 410 do not affect the scanning budget in any way, but soft 404 does, since nothing is added to the index, and resources are spent.
“Therefore, you should not redirect all 404 errors to the home page or category page. This is especially true for large resources,” said the Google representative.
You can listen to this part of the discussion starting at 26:10 minutes of the podcast.
Previously, John Mueller, during one of the webmaster meetings, also gave an explanation about soft 404 errors. SearchEngines said that Google may treat pages with outdated content as “soft” 404 errors (non-existent pages that return a 200 OK code).
“If the user can no longer buy a product on the page, then this is considered a soft 404 error, although, in fact, it should be treated as a normal 404 error. If you have thousands of such pages, then you should not set up redirects until they are found a suitable replacement. The fact that an item is not in stock does not mean that it will not be available in the future. So by default, you should not redirect old product cards to the home page.
Another thing is if a URL is found that is a really good alternative to the current one. There is a difference: either you really want to redirect users to another page, or you want to set up a 404 error in this way. In the second case, we will regard this as a soft 404.”