No matter what, changing your domain name will affect your search engine rankings, largely because each search engine responds differently to such changes, but you can substantially limit the damage done. Google has taken the lead as usual in dealing with URLs that change and will quickly index the new file with virtually no interruption if you follow some fairly straightforward procedures. AllTheWeb quickly followed suit. Unfortunately, the procedures described below do not work in the same way on the other major search engines.
The critical element in successful url redirecting or domain forwarding is taking the time to make sure that ALL links to your old page from directories and other websites are updated. That step must be done. Unfortunately, it is the most difficult step, as many links may be on sites that are neglected or even abandoned.
Google has published guidelines on changing your URLs. See, Google Information for Webmasters : "Once your new site is live, you may wish to place a permanent redirect (using a '301' code in HTTP headers) on your old site to inform visitors and search engines that your site has moved."
If you are moving your website and are not a server administrator, you should contact your server administrator and ask that they use the Apache URL Redirect directive to permanently "301" redirect each of your old files to their corresponding new locations. If you are a server administrator, then you can get more in-depth information by visiting Apache.org.
There are basically two ways to accomplish the URL redirect. You can either create a .htaccess fileand put all your individual redirects in that file, or you can modify the server configuration file (httpd.conf ) and define the redirects there.
You can check to make sure the redirects were done correctly by using our URL Redirect Server Response tool. Just type in the old url and click "Check Redirect." Your URL redirect will be tested and the page will reload. In the top of the right-hand column, you will see the results of your redirect test. The second line should read, "HTTP/1.1 301 Moved Permanently ." If it doesn't, then ask your server administrator to read the reference resource mentioned just above.
With Microsoft IIS, you can easily redirect one root url to another root url, but it is not so easy to redirect specific files. To do that, you need to know some code. However, if you keep your file structure intact as you change urls (i.e., the same url works for http://www.olddomain.com/filename.html and http://www.olddomain.com/filename.html then a novice IIS server administrator can accomplish the task. Just open the control panel, select the "Home Directory" tab, and click on "a redirection to a url."
Redirecting the root URL will automatically redirect all the files in the old URL to their corresponding file locations on the new URL. If you change your file names or site architecture, then you will need to do some workarounds.
One solution is to create a custom 404 error handling page in ASP which captures the url of the referring file, redirects the browser to the new url, and sends the server response, "301 Moved Permanently." It works quite well.
One common mistake many Webmasters make when they launch a new site at a new domain is changing the file naming and hierarchical structure of their website. There are often good reasons to change the file naming, but at times it appears to be done for no reason whatsoever. It is best if you can use the file names that have already been indexed by the search engines.
Another common mistake is the use of the META Redirect tag to redirect visitors from an old page to a new one. Search engine spiders do not follow META Redirect tags, so they should not be used. In addition, using the META Redirect tag forces your visitors to first load the old page, then load the new page, which is a drain on a site with substantial traffic.
If you have thousands of files on your site and you don't have the time to redirect every single file from the old domain name to the new one, you should at least redirect all the files that have been indexed by the major search engines.
To find out which files from your site have been indexed, use our Free SEO Analyzer. It will tell you which files from your site are indexed by all the major search engines, so you'll know which ones you need to redirect.