What is the difference between 301 and 302 redirects in SEO?

HTTP Response Status Codes are designated numbers that indicate the web server’s response to the requested URL. These codes inform the browser, and search engines crawlers, on how to handle the request. Among the most well-known of these codes is the 404, aka “page not found.” But in reference to Search Engine Optimization, the 301 and 302 codes are just as important. That variance can make a world of difference in your SEO efforts, ranking, and overall effectiveness.

What is the difference between 301 and 302 redirects in SEO?

What are those 301 and 302 numbers anyways?

The official registry of HTTP status codes lists five classes of status codes, with the first digit of the status code identifying the response class. The 3xx means in this case means the status code is in the redirect class.

Now if you are familiar with SEO and read about it online, you have almost certainly heard the phrase “link juice.”  This is where the redirect status codes come in to play. If you need to suggest to the search engine crawlers that your page, content, URL, or site has moved, then you need to redirect them. The status of that redirect has substantial importance in properly reassigning the “link juice” or ranking value.

What is a 301 redirect?

A 301, or permanently moved, is a redirect that carries and distributes in an absolute manner. You should use a 301 to signify to the crawlers that your content has moved permanently – as in forever.

When should I use a 301 redirect?

An example of when to use the 301 redirect would be if you have changed domains or if you launched your site in a new CMS and your URL structure has changed. Creating 301 redirects for your old content to point to the new content will tell the search engines that you have moved from A to B for good. This will allow search engines to direct ranking and value signals to the new URL because they understand this location to be the new, permanent home for that content.

What is a 302 redirect?

A 302 status code means Found, or more commonly referred to as “temporarily moved.” This redirect doesn’t carry or pass the link value to the new location. What it does do is get the user to an appropriate location for you so that you aren’t showing them a broken link, a 404 page not found, or an error page.

When should I use a 302 redirect?

You might ask, “If it doesn’t distribute SEO value then why would I use it?” A good example of when to do a 302 redirect would be in an e-commerce setting. Let’s say you have a product that you no longer have for sale– maybe the product is seasonal, out of stock, or is something that you might sell again. In this case, you might want to use a 302 redirect to send the user to the category page. If the product outage is going to be for any real length of time it might not make sense to send the user to a page that they cannot order from, so you redirect them to the category page allowing them to look at similar items. And with that 302 you are telling the search engine crawlers that your content is just offline temporarily and they should keep the value of that page intact and not pass it to another URL.

When approaching your SEO and changes in your site’s location or structure, it is important to remember the technical signals. Improper use of the signals could result in a catastrophic loss in link value for your content, which can be tough to overcome or rebuild.

Bottom line: pay attention to the status, because no one wants to redo their content distribution efforts due to the “simple” difference between the numbers 301 and 302.

{photo used under Creative Commons from jerryonlife – flickr}