404 is an error message code that is generated when a page on a website is not found. It can be caused due to many reasons like the page was deleted/renamed by the webmaster or a visitor mistyped the URL or some other technical issue. Sometimes, webmasters just ignore this message- which is not the right way to go. High numbers of 404 errors are bad for SEO which translate into bad user experience and ultimately lower rankings.
Why is 404 Bad for SEO?
Search engines and users both do not like it if a blank page appears when their desired page is not found. So it becomes increasing critical to address this issue and present search engines and users with a page which they wanted to see in such situations to improve SEO and user experience.
Just as in real life, mistakes can be made by web designers too. Pages can be moved or deleted by mistake. When a page is deleted, the ink that pointed to that page still remains in the sitemap and in search engine results. When a user clicks on it, their browser takes them to a “404 Error” page because the desired page does not exist anymore.
When a ‘not found’ page is not handled correctly, two issues can arise for your website and business. First, the search engine algorithm gets confused about where to pass the link juice of that page, therefore resulting in lower rankings. Secondly, visitors feel clueless about where to go in such situations resulting in a bad user experience. Therefore, traffic, links and hence, potential conversions can be lost if the error is not handled correctly.
A small percentage of ‘not found’ pages is quite acceptable. But if a large proportion of such pages are present on a website, it can have negative impacts on a website’s accessibility and SEO.
How to Deal With 404 Errors
If a page was receiving lots of quality links, it is advisable to redirect such a page to the most relevant alternative page or, in extreme cases, to the home page.
However, in some cases a separate page can be created for such purposes. This page will only be visible when such an error occurs. That page must have well optimized content with a message along with a search box, sitemap and some contact information.
If you want to see if a page is generating 404 error message or not, you can type in the URL into the Google Webmaster Tools feature ‘fetch as google’.
There are many tools available to find ‘404 error’ pages such as Screaming Frog.
There is another similar error which is called 410 (Page permanently gone), but from an SEO point of view, the treatment for a 410 error page is similar to that of a 404 error.