303 Redirects & SEO

16 Jul 2010, Posted by admin in Nohat, 16 Comments

303 Redirects & SEO

303 redirects are never really talked about in the SEO community, and in truth it’s for good reason.

According to, 303s basically mean “see other”. The redirecting URL shouldn’t be cached and it generally indicates that the content is held elsewhere. Importantly though, it says this:

“Many pre-HTTP/1.1 user agents do not understand the 303 status”.

SEOs generally know to use a 301 for the vast majority of redirects, but if you ever get a web dev or a design team that wants to use a 303, there’s now a good example of why it should be avoided here:

Wimbledon SERP in Google

A search for “Wimbledon” in Google currently shows a blank .com also ranking, just as a 302 often would. This implies that a 303 redirect won’t pass on link value to the main site, like a 301 would, and can cause the redirecting URL to also be listed in the SERPs.

For some reason, the URL 301 redirects most users to the correct domain, but will show search engines a 303. You can switch your user agent to Googlebot and check.

Yahoo and Bing treat 303s the same way:

Wimbledon Yahoo SERPs

Yahoo also doesn’t appear to see the .com redirect properly. And neither does Bing:

Wimbledon Bing SERPs

So, in summary – 303 redirects don’t appear to work properly to search engines. If you want your permanent redirects to be counted by the search engines, avoid them and use 301 redirect instead.

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July 16, 2010 10:23 am


Yes Dave – I love this kind of thing. Keep it up!

July 16, 2010 10:43 am

Sander Tamaela

Nice article!

But (concerning your example) if I was in control of the domain, I would keep the 303 in place (the 3 top spots are nice to occupy) until I need the link value of the .com domain.

July 16, 2010 10:52 am

rob hammond

Good post but am I missing something? serves (boom boom) a 301 for me

July 16, 2010 12:16 pm

Scott McLay

Good overview of the 303 redirect, I have seen this before in the past, but it took me a while to actualy find the cause as i was looking for a 302 πŸ™

July 16, 2010 3:30 pm


@Sander That’s a fair point, I think for most sites (probably more commercial sites too) it’s more important to get those links, than an extra brand term listing – but you’re right, Wimbledon are probably not too concerned about their extra listing.

@Rob It’s a weird one this, it 301s to most people, but if you’re a search engine it shows you a 303. You can see it if you switch your user-agent to Googlebot.

@Richard & Scott – Thanks guys!

July 30, 2010 4:03 pm

Richard Vaughan


In live http headers I’ve got 301ing to which then in turn 303s to

Is that not what you are seeing?

So the 301 ( is indexed and the 303 ( is being treated more like a 302 rather than a 301!

All very strange.

March 31, 2011 9:23 am


Today I noticed a url-shortener, which uses a 303-redirect

August 20, 2011 5:26 pm

Forms and redirecting « DerEuroMark

[…] the comment in the method head as well as other sources explain one should NOT use 303 or you end up with broken forms for some users.   No […]

October 6, 2011 1:39 pm

John Benedict

Good sharing Richard Vaughan…

November 28, 2011 2:30 pm


seems to work fine at the moment, and also seems there is at least some juice, that is beeing passed…. I just noticed that today in googles german index. the new site is ranking at Pos. 3 (without any BL) the redirected one on Pos. 4. The Keyword is a quite heavy brand from the fiancial sector, so not any low hanging fruit! πŸ˜‰


January 2, 2012 2:59 am

Sandy Allen

Recently tested Yelp – and the URL redirects to the reviewed sites are all 303s.

October 5, 2012 8:48 am


Thanks for this information. You`re right – they are never really talked about in SEO – but in fact they should! πŸ˜‰

October 16, 2012 7:16 am

Mark Ryder

Removing the canonical tags after permanent 301 redirection won affect the site right

November 24, 2012 2:29 pm


Cheers Dave, hadn’t seen much mention of 303s before and Wikipedia seems to say they’re ok – so good to know the TRUTH πŸ™‚

December 12, 2012 7:50 pm


Well that’s just as I expected Google to treat redirects. So I’m using 303 when content is temporary not available, and 301 when it has moved to a new location.

I think more important questions would be:
– How long does a 301 redirect take until it’s definitive and the old url won’t be crawled anymore? (when you need to redirect hundreds of pages)
– What happens when you redirect 301 a page with keyword A to a page with keyword B? Will google show the new page when you search for the old keyword? I mean, does a page reputation go to the new one after a redirect?

February 6, 2013 5:50 pm

Brian Jensen

The first instance of a 303 I came across is on YouTube. It appears that recently (In an attempt to prohibit PageRank being passed from video to video) they changed the redirect to a 303. Previously they relied on the no-follow attribute which they still use but still passes some link equity. Anyhow, thanks for the great resource!

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