301 101: How Redirects Work

By George Zlatin

Eliminating pages from your website, changing your page URLs or domain name requires a lot of redirecting. If you don’t set redirects up, links to your site become a dead end – you lose valuable inbound links.

In essence, you’re setting up detour signs – “This thing is no longer here. Go over here.” And to make sure your website isn’t an internet version of Chicago where everything is under construction all the time and you suddenly run into roadblocks for no particular reason, you’ll need to implement the right type of redirects on your website.

But first, some education. Let’s talk about what a redirect is and what it actually does.

When you type digitalthirdcoast.com into your browser, the browser sends a request to our server. The server then sends your browser back the page that was requested. A redirect places instructions on the server to provide something different then the original request.

When the browser asks for Red, the server has instructions saying “Red isn’t here anymore, give them Pink instead.” And then Pink is delivered to the user for optimal user experience.

Types of Redirects

301:

A 301 redirect is a permanent redirect, and by far the most common type of redirect. It is a server-side redirect.

Typing a URL into your browser or clicking on a link sends a request for the page to the server of the website. A 301, “moved permanently,” redirect is a set of instructions which are executed when the request hits the server, automatically re-routing to a different page.

Implementing 301 redirects is the focus of most SEO efforts during a site migration. This specific type tells the system that the page has moved permanently to a new page on your site.

302:

302 redirects are not as common as 301 redirects and are considered a “temporary relocation.” Implementing them typically happens during site maintenance, but since most sites have a maintenance mode where developers and admins can test changes before they go live, this type of redirect is rarely used today.

300:

“Multiple choice” redirects brings up multiple options for the same resource. It’s rarely used, but it does have some important applications – multilingual sites and different file extensions being two good examples.

101:

“Protocol change” used to be more common for things like HTTP to HTTPS, but now that’s handled by a “RewriteEngine” that uses 301s

Redirect Protocols

Server-Side:

Redirects are by far the most common method of redirection where the request is handled at the server level. The original request does not load, and the server reads the instructions and delivers a different web page rather than loading the first request.

Client-Side:

Redirects occur when it is encoded into a web page rather then set on a server level. The request for the site is sent, the resource begins to load, and then there are directions during loading that reroute them.

Wildcards:

Allow for redirecting of multiple pages to one resource. For example, if you have com/category/* and your platform supports wildcarding, then all subpages of “/category/” will redirect to a specified resource.

Things That Aren’t A Redirect

404:

When a URL does not exist and the server has no instructions on where to route the user request, a 404 error message is delivered. It’s highly recommended you set up a 404 page for your users which allows them to search for their selected resource, or correct page, rather than simply bouncing off the website.

Canonical:

Canonical tags don’t return a status code number; instead, they specify to a search engine that two pages contain very similar content. Specifying a canonical allows search engines to understand that two pages aren’t duplicates of one another; they simply have the same information. A common use of canonical is in the world of e-commerce where two category pages will often contain the same products.

418 I’m a Teapot error response:

The web is built by people who are addicted to caffeine, so it makes sense there’s a whole set of protocols and statuses built for it. Personally I’m waiting for the 372 Red Bull Gives You Wings protocol.

The Effects of 301

Most likely as you move things around your site and remove old pages, you’ll be using the 301 redirect protocol to make sure everything’s in line. Here’s what you need to know.

301 redirects are executed very quickly:

(it’s really just a line or two of code) so they will not have an significant impact on site speed.

Multiple URLs can be redirected to one URL…

But one URL can’t be redirected to several URLs.

A page can not be 301 redirected to itself:

Or to a page which 301 redirects to itself. This creates an infinite loop and nothing will ever load- it’s basically webpage ping-pong.

Link Equity:

This is the big one, a 301 redirect passes nearly all link equity to the redirected page.

Link Equity and 301s

According to Moz, anywhere from 90-99% of the link value passes from the original page to the redirected page. Which sounds…pretty good. There are some pitfalls to this, however:

The context and anchor text of the links matter:

So if you direct a page that was about flowers to one about balloons, the relevance of those links decreases. Even redirecting link value from a page about roses to a page about flowers – it’s still not exactly the same, and a lot of those links might have anchor text containing “roses” and the flowers page only mentions roses once. It’s a bit of a disconnect that could affect the effectiveness of your links.

Conclusive information:

There is no conclusive information on how much link value is passed when multiple pages are redirected to one. You’re getting the benefits of several pages worth of link equity….but are there diminishing returns on that link equity? It’s impossible to tell for sure, but early data suggests each one has less value then the first, and after 5 no value is passed between pages at all.

Google has confirmed that it passes this link equity via this redirect;

Bing and Yahoo! handle things a bit differently. Back in 2010, Bing didn’t pass equity at all, but it appears they updated that policy. Most of the time, Google is the engine bringing home your bacon, but if you have lots of volume from Yahoo or Bing, you might want to take extra precautions.

The Bottom Line

It’s best to keep URLs intact as you migrate to avoid any loss of link equity and to keep things as clean as possible, but it’s pretty likely that you will have to make at least a few redirects. The best practices for this include:

Don’t chain redirects – don’t redirect to a URL that’s already being redirected.
Make sure they are set up on the server side
Use absolute URLs (not nodes or page numbers; this leads to broken links and redirect chains)
Keep in mind the anchor text of inbound links to a redirected page needs to still relate to the page you’re redirecting too.
Different search engines handle redirects differently
Always redirect a removed page to the most similar