What Is 404? 4 Common Website Errors and What They Mean

Most of the time, visiting a website is a simple affair. You type in the name of the site you’re interested in or click a browser bookmark, and you see it within a few seconds.

But what about when it goes wrong? Sometimes, you’ll see various errors alerting you to problems with visiting that website. While some of these are out of your control, you can troubleshoot others to find out what’s wrong.

Let’s quickly review some of the most common website errors. Note that errors starting with 4 (like error 451) are client-side errors (issues with your computer), while those starting with 5 are server-side (problems with the website).

1. Error 404

404 is a common error. It signifies that the page you were looking for doesn’t exist. This often occurs when you click a broken link, or if a website moves a page without redirecting it properly. But it can also happen if you mistype a URL.

When you see a 404, check to make sure that you haven’t entered the wrong address. Then try a Google search to find the right page, as it may have moved.

2. Error 401

A 401 error means that you need authentication to access the page, but don’t have it. This usually occurs when you need to log into a website to access something but haven’t done so yet.

If you see this, try visiting the main page of the site and logging in again.

3. Error 403

A 403 error signifies that you’ve made a valid request, but the server won’t complete it because you’re not allowed to access it. This is different than a 401.

A 401 tells you that you haven’t logged in and so it can’t authenticate you. But a 403 error says that it knows who you are, yet won’t let you access the page. Typically, this means you’ve stumbled across something private and need to access the website administrator for access.

4. Error 504

A 504 error signifies a gateway timeout, meaning that a server the website relies on isn’t communicating with it quickly. When this happens, you won’t be able to access the website until its administrators resolve this issue. You can try refreshing the page a few times, but you’ll likely have to wait until it’s fixed.

For some funny errors, check out ridiculous Windows error messages.