Farewell to soft 404s

Tuesday, August 12, 2008

We see two kinds of 404 ("File not found") responses on the web: "hard 404 error" and "soft 404 error." We discourage the use of so-called soft 404 because they can be a confusing experience for users and search engines. Instead of returning a 404 response code for a non-existent URL, websites that serve soft 404 errors return a 200 response code. The content of the 200 response is often the home page of the site, or an error page.

How does a soft 404 look to the user? Here's a mockup of a soft 404: This site returns a 200 response code and the site's home page for URLs that don't exist.

a user confused by a soft 404

As exemplified above, soft 404 errors are confusing for users, and furthermore search engines may spend much of their time crawling and indexing non-existent, often duplicative URLs on your site. This can negatively impact your site's crawl coverage—because of the time Googlebot spends on non-existent pages, your unique URLs may not be discovered as quickly or visited as frequently.

What should you do instead of returning a soft 404?

It's much better to return a 404 response code and clearly explain to users that the file wasn't found. This makes search engines and many users happy.

example of a 404 response header example error message returned to the user explaining that the content is not found

Can your webserver return 404, but send a helpful "Not found" message to the user? Of course! More info as "404 week" continues!