How to properly implement 300 Multiple Choices pages for SEO?

Question

At the moment, when a URL isn't found, I'm serving a 404 page which shows a list of partially|fully matched alternative pages that the user is may looking for, without saying that is an error page.

If no any similar page is found, I show instead the Not Found error message.

Basically what I just do there is searching pages that match the "keywords" in the URL and show the list, instead showing the error.

Now, instead serving it as 404 I want to know if I can make improve my SEO returning a 300 Multiple Choices status code instead, which to me seems exactly what I'm doing already.

Will these pages be indexed by Google?

If yes, should I allow that? Many generated URLs may be actually useful to be found in Google SERPs, since that "disambiguation page" will implicitly explain differences between two or more similar resources... but I'm worried of people appending bad words in the URLs and linking to those, just for to manipulate my ranking.

Answer 1

A 300 redirect is not a good choice because it is not well supported by browsers. For example, see this post on StackOverflow where Roy Sharon discovers that Safari doesn't present a list to the users to choose from:

Okay, after not being able to find information re how do major browsers handle status code 300, I've downloaded the webkit source code and searched for the answer myself. It seems that webkit handles status 300 like the other redirection status codes: redirect according to the Location header, or present an error to the user if this header is missing. So, it seems that @Julian-Reschke was right after all: My solution doesn't work. :-(

You don't want Google to index pages that are nothing but a list of links anyway. These would not be good landing pages for users. Google would view them as "shallow content" and maybe even "doorway pages". As such, your 404 status is fine for these pages.

The only drawback for 404 pages is that Google isn't able to pass Pagerank to your site if somebody links to one of these pages. You could consider 301 redirecting to the first of the possibilities. Certainly if there is only one result from your search, this makes a lot of sense.

I have implemented this myself and I use a redirect to the first result even when there are multiple possibilities. For example on my currency conversion website if the URL is /dollars, I redirect to the "US dollars" page despite the fact that there is also a "Canadian dollars" page.