An Introduction To Using 301 Redirects for SEO
301 redirects are regularly used by SEO engineers to clean up the architecture of a page, update old or out-of-date content, solve duplicate content issues and improve overall user experience, often hoping that these changes will also have an impact on a sites’ rankings in Google, Bing and Yahoo (most notably the former).
One of the main reasons for this is that 301 redirects (unlike 302 redirects) pass what we call ‘link equity’, i.e. they pass some of the power gained from quality links over to the new page. But how much power do they pass? What’s the difference between a 301 and 302 redirect? Can 301’s also pass negative link equity?
To answer these questions and a few others, we’ve put together the following introduction to using 301 redirects for SEO:
1. The difference between 301 and 302 redirects
There is a very simple difference between the two types of redirects – a 301 redirect is permanent (designed for when a page has permanently moved to a new location) and does pass link equity. A 302 redirect is temporary, and does not pass link equity. Nice and simple.
*It’s worth noting that in recent months, it has been suggested that 302 redirects can in fact pass link equity – Duane Forrester from Bing even confirmed that this is often the case in his Tweet – but as a general rule of thumb it’s best to treat the description above as accurate and use 301 redirects when you want to pass link equity.
2. How much link equity is passed by 301 redirects? Do they pass negative link equity?
There was some debate on this question a couple of years ago, and even now the exact percentage seems to change slightly depending on who you’re talking to. With that said, the general consensus is that 301’s pass around 85% of the original link equity over to the new page. This percentage has come about from a combination of intense debate between high level SEO brands, a phenomenal amount of testing (most notably from Moz) and statements made by Google themselves.
So, if that’s the case, then is it fair to assume that 301 redirects will also pass negative link equity?
In the past, the answer to this was most likely ‘no’, but since the Penguin update (and subsequent refreshes), which heavily targeted low-quality backlinks, the general opinion of the SEO community is that negative links, and their subsequent impact on a site, is passed on to the new page/domain with a 301 redirect.
As a result, it’s best to avoid redirecting domains that you know have low quality or spammy links pointing to them to your new domain or page. Similarly, if you’re looking to improve your rankings and you know you have bad backlinks pointing at your target domain via a 301 redirect, removing this redirect is often an effective tool in improving your overall domain authority and subsequent rankings.
3. Multiple 301 redirects to a single page
Hopefully most people interested in SEO know better than to redirect multiple pages or domains to a single URL or homepage, but it’s worth covering here just in case. Having numerous pages linking back to, for example, the homepage, is not only very unlikely to result in ranking improvements, but could even completely negate any positive link equity being passed by those pages. In fact, in a recent YouTube post from John Mueller (of Google Switzerland), Google representatives make a clear suggestion that bulk redirects to the homepage could be treated as 404 pages.
Instead of utilising this bulk redirect tactic, you should take the approach of redirect each individual URL to a page that is as closely related as possible, or if the page doesn’t hold much link value in the first place, simply add a 404 page in its place.
4. The importance of relevancy
This is a common mistake SEO engineers make – they find a page that has a decent amount of link equity, and redirect it to a page on their target site even if it’s not at all relevant. Ideally, you should be redirecting pages to content that is as closely relevant as possible; it doesn’t need to be a perfect match by any means, but it should at least be on a similar topic or in the same industry.
If you’re redirecting pages to completely unrelated content, then you’re running the risk of having the link equity from the original page ignored altogether (see Google’s Information Retrieval Based on Historical Data patent for further reading).
Hopefully that’s given you a solid introduction on using 301 redirects for SEO purposes, but if you have any questions or anything is unclear, don’t hesitate to let us know in the comments section.
Preview image courtesy of onlinebusiness.volusion.com