HTTP 4xx status code
404 Not Found
404 Not Found is the error everyone has seen. It means the server received the request and understood it perfectly well, but there is nothing at the address asked for. The request was fine; the destination is missing.
Most 404s come from a handful of ordinary causes. A link points at a page that has been moved or deleted, someone mistyped a web address, or a page that used to exist is simply gone. Because the problem is the address rather than the request itself, retrying the same URL will keep returning 404 until either the page comes back or the link is corrected.
For people running a website, 404s matter more than they look. A scattering is normal, but a lot of them, especially from internal links, means visitors and search engines are hitting dead ends. The fix is usually one of two things: restore the missing page, or add a 301 redirect from the old address to wherever the content lives now. A helpful 404 page, one that offers a search box and links back into the site, turns a dead end into a way forward, which is why so many sites give their 404 page some personality.
Frequently asked
What does a 404 error mean?
It means the server could not find anything at the requested address. The request reached the server fine, but there is no page there, usually because the link is broken, the page was moved or deleted, or the URL was mistyped.
How do I fix a 404 error?
As a visitor, check the URL for typos or go back and follow a working link. As a site owner, find what is linking to the missing page and either restore the page, or set up a redirect from the old address to the correct one.
What is a soft 404?
A soft 404 is when a page tells the visitor it is missing but the server still returns a success code instead of 404. Search engines dislike this because it hides the error, so a genuine missing page should return a real 404.