301 Redirects are critical for any website redesign as they instruct search engine crawlers (automated computer programs that scan the content on your website and add information to their database) to redirect old web page addresses to new addresses if changed during the website redesign process or general maintenance of a website.
But Why Do 301 Redirects Matter?
Over time, the pages on your website build up data. This can include links from other websites or directories, often referred to as backlinks. Backlinks are an important part of the formula search engines use to rank websites. One of the worst things a company can do is rename, delete, or change the URL of a page without giving instructions to bots/crawlers that the address has changed.
Quick Example of 301 Redirect
Previous website address: http://www.yourdomain.com/about.html
New website address: http://www.yourdomain.com/about/
Though the two addresses above may appear somewhat similar, they are very different and the bots/crawlers will not make the connection without proper instructions giving them a map to the new address. A very common way to handle this redirect is with an HT Access redirect. This is a special file found on Apache Web Servers. Within the HT Access file, the following instructions can be added to provide the mapping instructions:
301 redirect line: Redirect 301 /about.html http://www.yourdomain.com/about/
Now with that added, any time the old page is visited, it automatically redirects the user to the correct page. This will help to pass what has been coined as “link juice” to the new page, maintaining the historical data that page has accumulated.
Caution: 301 Redirects Can Easily Break Websites
301 redirects are case sensitive and even an extra space added when writing the instruction can break your website. If is often a good idea when adding lots of redirects, to do them in smaller chunks so that if something does happen, it is both easier and faster to track down the problematic line.
Be sure to test thoroughly when adding redirects.