404 Errors are when content or links on your website are not found, and a 404 error is returned.
A 404 error – “Not Found” is when a URL on a website or a resource such as CSS file or image cannot be found. This could be because of a typo in a URL, a programming error or perhaps the file was deleted. No matter the reason, when a file cannot be found, a 404 – Not Found message will be displayed.
Are 404 errors dangerous for my website?
Yes, but how much depends on how many and how prominent they are. Not only does 404 errors give a bad user experience for your visitors, but it also shows Google and other search engine crawlers that you have mistakes on your website that you do not fix, and if they continue finding a lot of 404 errors, it will give a negative impact. It can also mean an increase in server resources because it takes processing power to make a request to a URL that does not exist and it also takes up extra resources serving different files to display the 404 error page. That being said, 404 errors are also a way of making sure Google search robots eventually forget about your old URL if you want it to be gone from their index and search results. This could happen if your website is hacked and you used 404 errors as a way to clean old spam-injected hacked URLs (sigh, I hate cleaning that stuff up).
How to turn on 404 error monitoring
404 Errors are not enabled per default in SEO Booster; it is an optional feature you need to activate manually.
To turn on 404 error detection, go to SEO Booster -> Settings and activate the setting.
SEO Booster will now monitor 404 Errors, and you can see the list under SEO Booster -> 404 Errors
404 Errors page
On the 404 Errors page, you can see all 404 errors in a list with some visitors detected.
You can mark individual errors and delete them with clicking the “Bulk Actions” drop down, select “Delete” and click the “Apply” button.
You can also reset all 404 errors by clicking the “Reset” button.
Note – any and all errors you delete will show up again next time someone visits that error page.
Use the list for prioritizing the most relevant pages to redirect or leave alone.
The 404 error page shows you the pages and files not found on your website. These can come from visitors on your website or search engine robots trying to locate a file.
If you are not certain what 404 errors are, and why they are bad for your website, read this article: What are 404 errors?
Where referrer information is available you can see in the column to the right where the link was from.
Once you have taken action on the not found content you can either choose to mark individual links and remove them from the list or use the “Reset 404 Errors” button on top of the page to delete all.
Note that some files are supposed to return 404 – not found. This can be from robots crawling for WordPress plugins that are known to have vulnerabilities and then try to break in.
When you have manually deleted a page on your website then consider setting up a redirect to other another URL related to the content, such as a product category for e-commerce products or the homepage itself.
You can either do this manually by editing your .htaccess file or use a plugin such as the great WordPress SEO plugin by Yoast or the very effective and easy Redirection plugin by John Godley.