Simply put, a URL redirect is way of telling one page to show up instead of another whenever there is a request to access the latter.
This is a way of sending both users and search engines to a particular URL instead of the one requested originally.
Types of URL Redirect
There are basically three types of redirection in terms of coding.
- 301 redirect – Moved Permanently (used for SEO)
- 302 redirect – Moved Temporarily – ‘Found’ in HTTP 1.0
- Meta Refresh
301 Redirect – Moved Permanently
This is the redirect to be used when a URL is permanently moved to another.
It usually passes up to 99% of the SEO equity and therefore finds a wide array of applications with the SEO community.
Unless there’s a very strong reason to go for another type, you should always go with a 301 redirect.
302 Redirect – Moved Temporarily (Found in HTTP 1.1)
There have been rumors of some Google employees revealing that the search engine treats both 301 and 302 the same.
However it’s always safe to use 301 except only when the URL is moved temporarily.
This redirect has two different versions in HTTP 1.0 and HTTP 1.1.
As suggested in the heading, it’s Moved Temporarily in 1.0 and Found in 1.1.
307 Redirect – Moved Temporarily (HTTP 1.1 Only)
This URL redirect is only available only in HTTP 1.1 and therefore you will rarely come across it.
This redirect is considered as 302 in most cases.
The only exception is when the redirection happens due the temporary movement of content due to maintenance and other related activities in addition to identification of servers involved as being HTTP 1.1 compatible by the search engines.
There is no fool proof way of determining whether a server has been identified as HTTP 1.1 compatible by the search engines.
Therefore, the best practice is to use a 302 redirect.
Redirects Due to Meta Refresh
This type of redirect occurs at the page level rather than at the server level, unlike other redirects.
The most common example of such redirects are the ones that come with a 5-second countdown with a message like “If the link does not open within the next 5 seconds, click here.”
Such redirects are not generally used in SEO unless it is absolutely essential.
This is because, they rarely pass significant amount of page equity, and they fare poorly in usability.
SEO Best Practices for URL Redirect
There are several instances of URL redirect used by SEO specialists.
Whether you are redirecting a URL within a domain or across two different domains, there are a set of best practices that you need to keep in mind.
Although there are multiple options available to transfer the content of one URL to another permanently, a 301 redirect is the beat option.
Both the browsers and the search engine crawlers interpret this permanent transfer in a way that’s convenient for SEO practices.
They understand that not only just the content has moved but also the SEO values need to be transferred.
However, the transfer of SEO values from the old URL to the new may not be immediate.
This can happen due to several reasons.
The primary reason is the frequency of the search engine bots crawling your site.
Search engines crawl a particular site based the historical data of site updates.
If the crawlers think that your site seldom update content, it might crawl your site less frequently than others.
So it will take some time before your new URL will be indexed.
Another common reason is that the new URL might not be resolved properly.
To fix this issue, be sure to work closely with the technical staff that handle the coding bit of your site.
Transferring content and redirecting URLs from one domain to another is one of the biggest challenges not only for the SEO specialists but also for the technical team.
As an SEO specialist, you must bear in mind that all the new URLs should be properly structured and the link hierarchy of the previous site must be followed as closely as possible.
Be sure to allow the search engines to fully crawl and index your site before you can take any remedial measures.
For an in-depth analysis of moving content between different domains refer to this article that exclusively focuses on this issue.
301 Redirect With Apache
A typical case study of moving URLs from one domain to another is the moving of seomoz.org from www.socengine.com/seo/.
The developers of the old site wanted a new domain for the SEO Moz site rather than being a sub-directory of the original site.
This redirection had to handle several file and folder name changes while using 301 redirects for better SEO value transfers.
For the sake of appearance, they also needed to forward http://seomoz.org to
http://www.seomoz.org. One of the more important reason other than aesthetics is also the issue of canonicalization.
A simple solution for this situation would have been to use the PHP’s header function from the PHP code that powered the site.
However, there was an easier and a much more effective way of implementing this. This was to use mod_rewrite module of Apache.
With this module, they did not have to comb through each line of the PHP code.
They simply had to match specific patterns of the entire folders and redirect them to new URLs.
Before using this module, it is always advisable to check if mod_rewrite is installed.
Most Apache installations will have this module installed just like the SEOmoz.org’s server that ran the Linux distribution FreeBSD.
To check if your version has the module installed, you need to add a simple line to the Apache configuration file or to the relevant .htaccess file.
The line “RewriteEngine On” will help you determine whether this module is working so you will not encounter any issues later on.
The context of operation of mod_rewrite module is either per-server or per-directory context.
If the developer needs to configure per-server context, he has to edit the Apache configuration file httpd.conf.
The per-directory context can be configured by editing the .htaccess files that are present in each folder that the developer wishes to configure.
If an admin cannot access httpd.conf, he has to edit individual .htaccess files.
Regular expressions, also known as regexes, are a string of characters that describes or matches another set of strings according to specific syntax rules.
These strings are used by code editors and tools to search and change blocks of code texts based on regular recurring patterns.
When it comes to URL redirect, the same strings can be effectively deployed so as to get the most SEO values from the old URLs.
The following list of regular expressions are the most widely used in URL redirect.
Five Potential Pit-Falls That You Need to Be Aware While Implementing URL Redirect
Whether you want to change the file extension and redirect the content to another domain or retain the file name and redirect it within the same domain, there are plenty of challenges with using URL redirect that you need to be aware of.
From clearly defining the situation and enlisting precise actions you need to take to the right way implementing the codes, the following five points will help you redirect the URLs so you can get the maximum SEO values to the new URLs.
The Bottom Line
As an SEO specialist, you will be undertaking URL redirect for a wide range of reasons.
No matter what the reason is, your primary objective should be to transfer as much as SEO values from the previous URL to the new URL as possible.
You will do good just to remember that 301 redirects forms the bulk of your redirects and they pass on most of the link juice.
You should be judicious while choosing 302, or in some cases 307 redirect, as they are meant to be used only for temporary movements.