What does that status code mean?

The server is ready for the rest of a large request. You will rarely see this on its own.

The server agreed to change protocol, for example to open a WebSocket.

The server is sending a preview of files the page will need, before the real answer.

Everything worked. The server sent back the page it was asked for.

A new item was saved on the server, usually after a form or app submitted data.

The server took the job but has not finished it yet.

The request worked and there is simply nothing to show.

Only part of a file was sent, which is normal for video and large downloads.

This address has moved for good. Browsers and search engines should use the new one.

The page is temporarily somewhere else. Common for log-in pages and region redirects.

After a form submission the server is pointing you to a results page.

Your saved copy is still current, so nothing new was sent.

Like 302, but the browser must repeat the request in exactly the same way.

Like 301, but the browser must repeat the request in exactly the same way.

The server could not understand the request. Often a broken link or a corrupt cookie.

You need to sign in first. The site itself is running.

Reserved for paid access. A few services use it when a bill or quota is overdue.

The server is up but refused to show this page. Many sites send this to automated checkers, so it does not always mean people are locked out.

The server is up, but nothing lives at this exact address. Check the spelling of the path.

The page exists but does not accept this kind of request.

The server could not offer the page in a format the request asked for.

The server got tired of waiting for the request to finish arriving.

The request clashed with the current state of something on the server.

The page was removed on purpose and is not coming back.

Whatever was being uploaded was bigger than the server allows.

The web address itself was too long for the server to handle.

The server does not accept this type of file or data.

An old joke code. Some sites use it to turn away bots.

The request reached a server that is not set up for this domain.

The data was understood but did not pass the server’s checks.

The server did not want to risk processing a replayed request.

The server wants the client to switch to a newer protocol.

The site is rate-limiting. It is running, but asking callers to slow down.

Too much data was sent in headers, often because of oversized cookies. Clearing cookies for the site usually fixes it.

The page is blocked for legal reasons in the region the request came from.

Something broke inside the website’s own software. Only the site owner can fix it.

The server does not support what was asked of it.

A front-door server (proxy or CDN) could not get a valid answer from the site behind it.

The site is overloaded or down for maintenance. It is usually temporary.

A proxy or CDN waited too long for the site behind it to reply.

The server refused the version of HTTP that was used.

The server ran out of space to finish the job.

The server found itself going round in circles and stopped.

A Wi-Fi login page or captive portal is in the way.

Cloudflare reached the site’s own server, but got an empty or strange reply.

Cloudflare is working, but the site’s own server refused the connection.

Cloudflare could not open a connection to the site’s own server in time.

Cloudflare could not find a route to the site’s own server.

The site’s own server accepted the connection but took too long to answer.

Cloudflare and the site’s server could not agree on a secure connection.

The site’s server presented a certificate Cloudflare would not trust.

Cloudflare could not look up where the site’s server lives.