Free Security & tech tool

HTTP Status Code Explorer

Look up any HTTP status code in plain English: what it means, what it does to your SEO, and how to fix it.

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Runs in your browser

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77 codes

Check a URL’s status

1xx Informational

The request arrived and is still being handled.

2xx Success

The request worked.

3xx Redirects

The content lives somewhere else, or hasn’t changed.

4xx Client errors

Something is wrong with the request, like a bad link or missing login.

5xx Server errors

The server failed to answer a valid request.

Non-standard codes

Used by specific servers and services like Cloudflare and nginx, not by the HTTP standard.

What it checks

Every standard code
All codes in RFC 9110, plus WebDAV codes and later additions like 429 and 451.
Non-standard codes
Cloudflare 520–530, nginx 444 and 499, LinkedIn 999 and more, clearly labelled.
What it means for SEO
How Google treats each code, like 301 vs 302 and 404 vs 410.
Causes and fixes
Why errors and redirects happen, and what to change on your site.
Search and filter
Find a code by number or by words, or filter by class.
A link for every code
Each code has its own address, like #404, to share with your team.

Questions

What’s the difference between 301 and 302?

A 301 says a page moved for good, so Google moves its ranking to the new URL. A 302 says the move is temporary, so the old URL usually stays in search. Use 301 (or 308) for permanent moves.

Should I use 404 or 410 for a deleted page?

Either works. Google treats them almost the same: both drop the page from search. 410 says the removal is on purpose. If there’s a replacement page, redirect to it with a 301 instead.

Which code should I use during maintenance?

503 Service Unavailable, with a Retry-After header. Google keeps your pages and comes back later. A maintenance page sent with a 200 can get indexed in place of your content.

Do 5xx errors hurt SEO?

Short outages don’t. Google slows crawling when it sees server errors and tries again later. If pages keep failing for days, they start to drop out of search.

All tools

HTTP Status Code Explorer

1xx Informational

100Continue The server got the request headers, and the client can go ahead and send the body.

101Switching Protocols The server agrees to switch protocols, usually to open a WebSocket connection.

102Processing DeprecatedThe server accepted a long request and is still working on it. It’s obsolete and rarely sent today.

103Early Hints The server sends hints, like which styles or fonts to preload, before the final response is ready.

2xx Success

200OK The request worked, and the server sent back the page or data.

201Created The request worked and created something new, like an account or an order.

202Accepted The server accepted the request but will finish it later, like a queued job.

203Non-Authoritative Information The request worked, but a proxy changed the response on the way.

204No Content The request worked, and there’s nothing to send back.

205Reset Content The request worked, and the client should reset the form or view that sent it.

206Partial Content The server sent only part of the file because the client asked for a range. Used for video streaming and resumable downloads.

207Multi-Status One response holds separate status codes for several items. Used by WebDAV file servers.

208Already Reported These items were already listed earlier in the same multi-status response, so they aren’t repeated.

226IM Used The server sent only the changes to a resource (a delta) instead of the whole thing. Rarely used.

3xx Redirects

300Multiple Choices The resource has several versions, like different languages or formats, and the client should pick one.

301Moved Permanently The page has moved for good to a new URL, and the old one shouldn’t be used again.

302Found The page is at another URL for now, and the original URL should keep being used.

303See Other Go to another URL with a normal GET request, usually after a form is sent, so refreshing doesn’t send it twice.

304Not Modified The page hasn’t changed since the client last fetched it, so it can use its cached copy.

305Use Proxy DeprecatedTold the client to use a proxy. It’s deprecated for security reasons, and browsers ignore it.

306(Unused) DeprecatedReserved. It was once called Switch Proxy and is no longer used.

307Temporary Redirect Like 302, but the client must repeat the exact same request at the new URL, including the method and any form data.

308Permanent Redirect Like 301, but the client must repeat the exact same request at the new URL, including the method and any form data.

4xx Client errors

400Bad Request The server couldn’t understand the request, usually because it was malformed.

401Unauthorized You need to sign in to see this, and you haven’t, or the login failed.

402Payment Required Reserved for future use. Some services send it when a payment is due or a plan limit is reached.

403Forbidden The server understood the request but refuses it. Signing in won’t help.

404Not Found There’s nothing at this URL.

405Method Not Allowed The URL exists but doesn’t accept this kind of request, like a form POST to a page that only allows GET.

406Not Acceptable The server can’t send the content in any format the client said it accepts.

407Proxy Authentication Required A proxy between you and the site needs you to sign in first.

408Request Timeout The server gave up waiting for the client to finish sending the request.

409Conflict The request clashes with the current state, like saving changes over someone else’s edit.

410Gone The page was removed on purpose and won’t come back.

411Length Required The server needs the request to say how big its body is, with a Content-Length header.

412Precondition Failed A condition in the request’s headers, like If-Match, wasn’t met.

413Content Too Large The upload or request body is bigger than the server allows. It used to be called Payload Too Large.

414URI Too Long The URL is longer than the server is willing to read.

415Unsupported Media Type The server doesn’t accept the format of the data that was sent.

416Range Not Satisfiable The client asked for a part of a file that doesn’t exist.

417Expectation Failed The server can’t meet what the request’s Expect header asks for.

418I’m a teapot An April Fools’ joke from 1998: a teapot refusing to brew coffee. The code is reserved, and some sites use it to turn away bots.

421Misdirected Request The request reached a server that can’t answer for this domain.

422Unprocessable Content The request was well formed, but the data in it is invalid, like a form with a bad email address.

423Locked The file is locked and can’t be changed right now.

424Failed Dependency The request failed because another request it depended on failed.

425Too Early The server won’t handle a request sent as TLS early data, because it could be replayed.

426Upgrade Required The server refuses this protocol and asks the client to switch to the one it names.

428Precondition Required The server needs the request to be conditional, like with If-Match, so changes don’t overwrite each other.

429Too Many Requests The client sent too many requests in a short time and is being rate limited.

431Request Header Fields Too Large The request’s headers, usually its cookies, are too big for the server.

451Unavailable For Legal Reasons The content is blocked for legal reasons, like a court order or a local law.

5xx Server errors

500Internal Server Error Something went wrong on the server, and it couldn’t say exactly what.

501Not Implemented The server doesn’t support what the request asks for, usually an unknown method.

502Bad Gateway A server in the middle, like a proxy or CDN, got a bad answer from the server behind it.

503Service Unavailable The server can’t handle the request right now, because it’s overloaded or down for maintenance.

504Gateway Timeout A proxy or CDN waited too long for the server behind it to answer.

505HTTP Version Not Supported The server doesn’t support the HTTP version used in the request.

506Variant Also Negotiates A server setup error: content negotiation points back at itself in a loop.

507Insufficient Storage The server ran out of storage space to finish the request.

508Loop Detected The server found an endless loop while handling the request.

510Not Extended DeprecatedThe request needs an HTTP extension the server doesn’t support. The spec behind it is now historic.

511Network Authentication Required You need to sign in to the network, like hotel or airport Wi-Fi, before you can browse.

Non-standard codes

419Page Expired LaravelLaravel’s code for an expired form: the security (CSRF) token was missing or out of date.

444No Response nginxnginx closed the connection without sending anything, usually to block unwanted traffic. Visitors see an empty response.

499Client Closed Request nginxThe visitor closed the connection before the server answered. It only shows up in nginx logs.

509Bandwidth Limit Exceeded Apache, cPanelThe site used up its hosting bandwidth allowance.

520Web Server Returned an Unknown Error CloudflareYour origin server sent Cloudflare an empty, unknown or unexpected response.

521Web Server Is Down CloudflareCloudflare reached your origin server, but it refused the connection.

522Connection Timed Out CloudflareCloudflare couldn’t finish connecting to your origin server in time.

523Origin Is Unreachable CloudflareCloudflare can’t find a route to your origin server at all, often because of a DNS or network problem.

524A Timeout Occurred CloudflareCloudflare connected to your origin, but it took too long to send a response (100 seconds by default).

525SSL Handshake Failed CloudflareCloudflare couldn’t set up a secure connection with your origin server.