While virtually every SEO knows how 301 and 302 redirects affect SERPs the 303 redirect remains fairly unknown because it is rarely used.
I came across a website linking to one of my sites with a 303 but I could not find a definitive answer of whether or not this link passed any PageRank. Information online about this was scarce and the only information I found was from people saying that only 301 redirects pass PageRank.
When I checked the status code for 303 redirect at w3.org it was “See other” . The description reads as follows:
“The new URI is not a substitute reference for the originally requested resource. The 303 response MUST NOT be cached, but the response to the second (redirected) request might be cacheable.”
This sounds very black and white and I my initial guess was that Google does not flow PR for 303 redirects. But I was curious, how was Google treating 303 redirects?
I set up an experiment to check how Google was handling the 303. Results below:
*Note: The translation for this keyword is NSFW
Google will show the search result with the URI that is initially requested. It will then show the Page Title and Meta Description (or other descriptive snippet) for the redirected page but it will show the URI from the redirecting page. It is caching the text from the final page but assigning it to the requested page.
How Google caches 303 redirects
Page A 303 redirects to Page B
Title: Page B
URI: Page A
Meta Description: Page B
Since page B does not rank for this keyword it is confirmed that the 303 redirect does not flow PR.
How did I set this test up?
- I chose a rare keyword that had very few pages ranking for it.
- On www.a.com I created two pages containing the keyword with the same exact content (www.a.com/a.htm .com/b.htm)
- One page (www.a.com/a.htm) was linked to internally multiple times
- One page (www.a.com/b.htm) was linked to externally with 303 redirects only from two domains (including www.marketingchip.com)
- The 303 redirects were created on the external pages (www.marketingchip.com/special-doors.html -> 303 -> www.a.com/b.htm)