A 404 error is the message that displays when trying to access a web page that does not exist. There are a few different ways to receive a 404 error, including:
If a website has recently been re-designed and/or updated, it is likely that old URLs could have changed and are no longer accessible, which would result in 404 errors whenever anyone attempts to visit those old URLs.
404 errors and SEO don’t mix well. If your web pages are experiencing 404 errors, search engine bots can’t access them and give them keyword rankings. So, changing the URL of a page that ranks well in Google will result in your website losing the SEO authority of that page unless you properly redirect it. In a similar fashion, if Google’s bots follow several backlinks pointing to a non-existent URL on your website, they could penalize the keyword rankings for your pages that work fine.
Sometimes, you will run into a scenario in which changing your URL is an SEO best practice – whether it is to enhance your page’s keyword focus or make your website navigation more user friendly.
To avoid the SEO penalties that come with changing your URLs, setting up a 301 redirect from the old URL to the new one is the best practice. Let’s say for example that you have the following URL:
As you can see, this URL is not secured and uses underscores instead of hyphens, which means Google’s bots read this as “seoguide” instead of “seo guide.” You may want to change this URL to this instead:
This URL is much more optimized for search engines. In this instance, we would set up a 301 redirect such that anytime someone clicked on a link pointing to the old URL, or even typed in the old URL manually, users (and search engine bots) would be brought to the new URL automatically. This is the easiest way to maintain your old page’s SEO value.