In your search engine optimization (SEO) toolbox, redirects are an important tool to master. Redirects are HTML or server commands that automatically redirect incoming links to another page.
With this tool, you can remove outdated pages from your website without losing the visitors that still go to those pages. You can also combine many domains (root names of website URLs) into one website so that they do not compete with each other.
With redirects, you can avoid creating duplicate content (web pages that search engines consider duplicates) that could hurt your ranking on search engine results pages (SERPs). And the best part is that redirects are not hard to learn at all.
This article covers the four main types of redirects. We explain what each type of redirect is for, although for SEO purposes only one type of redirect is safe – a 301 redirect.
4 Types of Redirects
In the world of the Internet, there are several types of redirects. These commands allow you to redirect visitors to your website from one URL (the web address of a page, e.g. www.wiley.com) to another (e.g. www.wiley.com/index.htm).
Often you need to use a redirect to redirect visitors pointing to an old page to the replacement page, especially if your site is being restructured so that files and directories need to be renamed and moved.
You also need to use redirects during normal maintenance of your site so that visitors who go to alternate URLs (for example, the non-WWW version of your domain instead of the WWW version, and so on) get to the URLs that contain the content they are looking for.
The various redirections, short for Redirection Status Codes, are defined by the World Wide Web Consortium (W3C), an organization that monitors Internet practices and creates standards that allow Web sites around the world to work together smoothly as one vast network. Webmasters have a number of tricks they can use, but not all of them are beneficial to you, your site, your users, or your search engine ranking.
In the case of redirects, only one of the available methods is truly search engine friendly, even though they are supposed to have different functions. In the following sections, you’ll learn more about the four most common methods for automatically forwarding a URL to another URL: 301 redirects, 302 redirects, meta refreshes, and JavaScript redirects.
1. 301 (permanent) Redirects
The 301 redirect is the preferred and most SEO-friendly form of redirection. The 301 redirect is also called a permanent redirect and informs a search engine that the page has been permanently moved to a new location.
This is the cleanest redirect because there is no ambiguity – search engines get a clear message that a page is a history and another URL has now taken its place. Imagine your favorite barbecue restaurant closing without your knowledge. Luckily for you, the next time you taste the delicious ribs, you’ll see a sign in the window: we have moved to a new location: 123 Yummy Drive.
This sign allows you to get back in your car and drive to the restaurant’s new location without too much inconvenience. A 301 redirect is kind of like a “We have moved” sign, only better. On the web, visitors do not even have to realize you have moved. Your website automatically redirects them to the new URL and displays the new page.
If you have registered a vanity URL (an easy-to-remember domain that’s not your company’s main domain name), you should set up a 301 redirect for the vanity URL so that when users go to it, they land on your real website instead.
For example, people interested in a movie that’s currently playing often type the movie title directly into their browser’s address bar, so movie studios try to register these URLs in advance. If you enter www.thedarkknight.com for the movie The Dark Knight (2008), you will be automatically redirected to
http://thedarkknight.warnerbros.com/dvdsite/, which is a subdomain on the Warner Brothers studio website. This is because the studio has secured the URL of the movie title and then redirected it to the actual website with a 301 redirect to get more website traffic.
For site maintenance, you could use 301 Redirects when physically reorganizing your pages and directories. For instance, you might redirect a page with a ghastly long URL (such as www.classiccarcustomization.com/extras/dashboard/gauges-chevrolet-impala/speed-or- tach/139348w9d.htm) to a new and cleaner URL address (like www.classiccarcustomization.com/chevrolet/gauges/impala-tachometer.htm).
You wouldn’t want to keep the old page location active on your website, but there are backlinks (incoming links from another web- sites) to the old page that you don’t want to break. So you can’t bring in the wrecking ball and just demolish the page — you need to redirect the old URL to the new one instead.
The right way to do this is to set up a 301 Redirect from the old URL to the new one. Then, users who click to come to the old page automatically find themselves looking at the new one; also, search engines get the message loud and clear.
When a search engine encounters a 301 Redirect, it does three things:
- Drops the now-defunct page from its index (database of web pages from which the search engine pulls search results) so that that page won’t be included in future search results.
- Includes the new page in the index, available for listing on search results pages.
- Transfers link equity from the old page to the new. (Link equity refers to the value of all incoming links to a page, which the search engines use to help determine a web page’s authority, or expertise, in its subject matter.)
The 301 Redirect is the SEO-recommended form of redirect because it reduces duplicate content within the search engine index. Duplicate content hurts your search engine rankings because search engines don’t want to show their users results that are essentially the same.
Therefore, if a search engine detects that two pages it has indexed are the same, it filters out the less authoritative page so that only one of the pages can appear in search engine results pages (SERPs).
Because a search engine responds to a 301 Redirect by dropping the old page entirely from its index, the chance of having two pages in the index with the same content is nil.
2. 302 (temporary) Redirects
Another commonly used form of redirect is the 302 Redirect, which signifies Document Found Elsewhere. You use this redirect for temporary relocations of a web page. Search engines see the new page as only temporary and continue to crawl and index the original location, instead.
Although the search engines claim to be able to interpret a 302 Redirect correctly, 302 Redirects can cause search engines to index duplicate content. Because duplicate content can cause search engines to filter pages from SERPs or assign pages to a supplemental index, for the sake of your SEO efforts, avoid using 302 Redirects.
Remember, 301 and 302 Redirects are server (not HTML) commands, whereas you use the types of redirects in the following sections within an HTML page.
3. Meta refreshes
A Meta refresh is a type of Meta tag (a command located in the Head section, or top section, of a web page’s HTML code) that tells the page to refresh automatically after a given time interval. When you refresh a page (by clicking the browser’s Refresh button, for example), it causes the page to reload and redisplay its contents. A Meta refresh command can be written in several ways:
- Refresh the page instantly (time delay = 0).
- Refresh the page after an interval (time delay = 1 or more seconds).
- Refresh the page repeatedly every X number of seconds.
- Refresh to another page (with or without a time delay).
Officially, search engines say that they handle Meta refreshes as follows:
- A Meta refresh that has a time delay of zero (0) or one second (1) is treated like a 301 Redirect.
- A Meta refresh that has a time delay of two (2) or more seconds is treated like a 302 Redirect.
However, we’ve observed that this isn’t usually the case. The search engines sometimes follow the link (as they would with a 301 or 302), but sometimes they don’t. Sometimes they index the new content, but sometimes they ignore it.
The search engines don’t handle Meta refreshes reliably, and that’s one reason to avoid using them on your website. Another reason to steer clear of Meta refreshes is that they look suspicious to the search engines.
Because Meta refreshes can be used to show different content to a search engine than to a user, they have traditionally been used by spam sites (websites that intentionally deceive search engines about their real content).
In one case, a site put up pages about baby blankets, but it was just a cover for a pornography site. The search engines didn’t see the porn content because the Meta refreshes delayed the change.
Many sites use Meta refreshes for legitimate reasons, as well. For example, the Los Angeles Times (www.latimes.com) uses a Meta refresh to refresh its front page every 600 seconds (ten minutes). It refreshes its front page to make sure that online readers always see the most up-to-date news because its stories change frequently.
However, search engine spiders don’t stay on the page for ten minutes to read the new content. The spider sees only what’s on the page at the outset. With a typical site (less well known than the L.A. Times), you don’t want the search engines to miss reading all your rich content, so you can have the maximum chance of ranking in search results.
Even worse, using a Meta refresh may get your site flagged as suspected spam. Search engines especially suspect sites that use a Meta refresh to fetch another page. Bottom line: If you need to redirect users and search engines to a new URL for a page, do it with a 301 Redirect.
4. JavaScript redirects
The search engines have a hard time following and indexing your pages properly if you program a redirect by using JavaScript (a scripting language that can add functionality to websites). JavaScript redirects give you the ability to customize the user experience, so the benefit is all on the usability end of the spectrum. (Usability refers to the user-friendliness of the site, which in this case runs counter to search engine–friendliness.)
A JavaScript redirect is also not recommended from an SEO perspective. The problem is that search engines cannot execute JavaScript and therefore cannot follow the redirect to a new page. With JavaScript, you can redirect users to particular versions of a page based on settings that can be detected by JavaScript.
You can detect the user’s browser type, Flash capability, cookies settings, and so forth. So you could deliver a page that has Flash animations to users who have the Flash plug-in installed but show a non-Flash-enhanced page to others — in other words, personalize it somewhat. That’s a useful application, but sites can also use JavaScript deceptively to create a “bait-and-switch” type of effect.
The search engines usually flag instances of JavaScript redirects for human review. Flagged sites are then dependent on the discretion of the human reviewer, who determines if the redirect benefits the user — in which case it’s usually allowed — or if it is a tactic for delivering a different page to a spider than it delivers to a user — in which case the site could be penalized for the spam (that is, thrown out of the index or buried way down in the results page).
And because the search engines continuously improve their spam-detection efforts, you want to make sure to keep your website practices in a safe harbor. We recommend that you never implement JavaScript redirects, except for personalization.
Even if you’re not doing something wrong, you don’t want to attract negative attention from search engines. It’s similar to driving when there’s a police car present. You watch your speedometer to make sure you don’t go over the speed limit even a little because that could catch the officer’s attention.
And if the police officer notices you, she might also notice that you’re not wearing a seatbelt or that your right taillight is out. You’re better off just not attracting attention in the first place.