When redirecting HTTP traffic to HTTPS, is it OK to redirect non-existant pages to a 404 error?

Question

We've recently converted several of our websites to require HTTPS on all pages. HSTS headers have been set and rules added into Apache to 301 redirect all traffic from HTTP to HTTPS.

However, similar to this question, we still have plenty of URLs from the old HTTP version of the website reported in Google Webmaster Tools as the "Linked from" source of 404s in the HTTPS version. This means search engines are trying to load URLs on HTTP and are being redirected to a 404 page on HTTPS.

It seems correct to redirect all traffic from HTTP to HTTPS, but from another perspective feels odd to be redirecting to 404s. I could try to reconfigure things so that non-existent URLs return a 404 on HTTP and stay there whilst redirecting valid requests to HTTPS, but it really doesn't seem either practical or secure.

Is this correct, or should I be doing something different to avoid redirecting to 404s? Should I even worry about this? Are there other SEO implications to consider?

Answer 1

It is very common practice to redirect to error pages when putting in a large class of redirects. In addition to wholesale HTTP to HTTPS redirects, this often happens when:

• You redirect from naked domain to www (or the other way around)
• You redirect from one domain name to another
• You redirect an entire directory

Redirecting to a 404 page may not be ideal, but I've never seen it cause any problems. Users get the same error message either way. Most users don't pay attention to the URL, so they are not aware that a redirect has even taken place. Because redirects are usually very fast, it doesn't even hurt the user experience from a page loading time perspective.

Search engine bots seem fine with it as well. They treat a redirect to a 404 pages as the equivalent of getting a 404 page in the original location.

It is always a good idea to pay attention to your top 404 errors. Fixing popular 404 errors can keep users from getting frustrated and can help your site take advantage of slightly broken external links.