HTTP status codes
Every HTTP status code in one place, explained in plain English. Look up a code, see whether the problem is on your side or the server's, and check what your URL returns right now.
1xx Informational
The request was received and processing continues.
| Code | Name | Meaning |
|---|---|---|
| 100 | Continue | The server received the headers; the client can send the body. |
| 101 | Switching Protocols | Switching protocols, e.g. to WebSocket. |
| 103 | Early Hints | Early hints for preloading resources. |
2xx Success
The request was processed successfully.
| Code | Name | Meaning |
|---|---|---|
| 200 | OK | The request succeeded. |
| 201 | Created | The resource was created. |
| 202 | Accepted | Request accepted; processing is still in progress. |
| 204 | No Content | Success with no content. |
| 206 | Partial Content | Part of the resource is returned (Range). |
3xx Redirects
A different URL is needed to complete the request.
| Code | Name | Meaning |
|---|---|---|
| 301 | Moved Permanently | Permanent redirect. |
| 302 | Found | Temporary redirect. |
| 303 | See Other | Redirect to another resource via GET. |
| 304 | Not Modified | Use the cached copy. |
| 307 | Temporary Redirect | Temporary redirect; the method is preserved. |
| 308 | Permanent Redirect | Permanent redirect; the method is preserved. |
4xx Client errors
The problem is in the request: URL, sign-in, permissions or data.
| Code | Name | Meaning |
|---|---|---|
| 400 | Bad Request | Malformed request. |
| 401 | Unauthorized | A login or token is required. |
| 402 | Payment Required | Reserved; sometimes used for paid access. |
| 403 | Forbidden guide | Access is forbidden. |
| 404 | Not Found guide | The resource doesn't exist. |
| 405 | Method Not Allowed | The method isn't allowed for this resource. |
| 406 | Not Acceptable | The requested content format isn't available. |
| 407 | Proxy Authentication Required | Proxy authentication is required. |
| 408 | Request Timeout | The client didn't send the request in time. |
| 409 | Conflict | Conflicts with the current state of the resource. |
| 410 | Gone | The resource has been permanently removed. |
| 411 | Length Required | The Content-Length header is missing. |
| 412 | Precondition Failed | A precondition (If-Match…) wasn't met. |
| 413 | Content Too Large | The request or file is too large. |
| 414 | URI Too Long | The URL is too long. |
| 415 | Unsupported Media Type | Unsupported Content-Type. |
| 416 | Range Not Satisfiable | The requested range doesn't exist. |
| 418 | I'm a teapot | A joke code from RFC 2324. |
| 421 | Misdirected Request | The request reached the wrong server. |
| 422 | Unprocessable Content | Well-formed request with invalid data. |
| 425 | Too Early | Risk of request replay (TLS early data). |
| 426 | Upgrade Required | A different protocol is required. |
| 428 | Precondition Required | The server requires a conditional request. |
| 429 | Too Many Requests | Too many requests; wait and retry. |
| 431 | Request Header Fields Too Large | Headers or cookies are too large. |
| 451 | Unavailable For Legal Reasons | Blocked for legal reasons. |
5xx Server errors
The request was valid but the server failed to complete it.
| Code | Name | Meaning |
|---|---|---|
| 500 | Internal Server Error | Unexpected server error. |
| 501 | Not Implemented | The functionality isn't supported. |
| 502 | Bad Gateway guide | Invalid response from the backend. |
| 503 | Service Unavailable | The server is temporarily unavailable. |
| 504 | Gateway Timeout | The backend didn't respond in time. |
| 505 | HTTP Version Not Supported | Unsupported HTTP version. |
| 507 | Insufficient Storage | The server is out of storage space. |
| 508 | Loop Detected | An infinite loop was detected. |
| 511 | Network Authentication Required | Network login required (e.g. hotel Wi‑Fi). |
52x Cloudflare
Errors between Cloudflare and the website's origin server.
| Code | Name | Meaning |
|---|---|---|
| 520 | Cloudflare: Unknown Error | The origin returned an empty or unknown response. |
| 521 | Cloudflare: Web Server Is Down | The origin refused the connection. |
| 522 | Cloudflare: Connection Timed Out | The origin didn't respond in time. |
| 523 | Cloudflare: Origin Is Unreachable | The origin can't be reached. |
| 524 | Cloudflare: A Timeout Occurred | The origin didn't respond within 100 s. |
| 525 | Cloudflare: SSL Handshake Failed | TLS with the origin failed. |
| 526 | Cloudflare: Invalid SSL Certificate | The origin certificate is invalid. |
| 530 | Cloudflare: Origin DNS Error | DNS or tunnel error reaching the origin. |
Frequently asked questions
What are HTTP status codes?
Three-digit numbers a server uses to report the result of a request. The first digit is the class: 2xx success, 3xx redirect, 4xx client error, 5xx server error.
Is a 4xx error always my fault?
No. 4xx means the server sees the problem in the request — that can also be a broken link on the site or a missing permission the owner must fix.
What are errors 520–526?
They are not standard HTTP codes but Cloudflare codes for problems between Cloudflare and the website's origin server.
How do I check my URL's status?
Enter a public URL in the status check on this page. It shows the final status, redirect chain and basic SEO signals.