4xx (Client Error)
A 4xx response occurs when the client can establish a connection with the server but can’t find the requested resource. It basically means that the page cannot be found at that particular address.
404s are among the most common, but you can review the full list of client side errors.
Why it matters
When deleting or moving pages, we want to make sure the proper steps have been taken to ensure a proper user experience and minimal loss of inbound link equity.
If 404s comprise a huge percentage of the site, then there might be an issue present.
General rule of thumb is that a website that doesn’t render properly for visitors makes for a poor user experience.
How to check
In Google Search Console navigate to Coverage > Errors
You will see a list of 40x errors occurring on the site
404 pages with inbound links or significant inbound traffic should be redirected to a similar piece of content.