| 500 |
HTTP 500 Internal Server Error |
The server hit an unexpected condition — usually an unhandled exception or misconfiguration in the applicatio… |
| 403 |
HTTP 403 Forbidden |
The server understood the request but refuses to authorize it — you (or the server process) are not allowed t… |
| 400 |
HTTP 400 Bad Request |
The server could not understand the request because its syntax, headers or body are malformed or invalid. |
| 422 |
HTTP 422 Unprocessable Content |
The request is well-formed, but the data fails validation (e.g. invalid email, missing required field). |
| 404 |
HTTP 404 Not Found |
The server can’t find anything at the requested URL. |
| 200 |
HTTP 200 OK (but something is still wrong) |
The request succeeded at the HTTP level — yet the page is blank, the data is wrong, or an error is hidden ins… |
| 414 |
HTTP 414 URI Too Long |
The request URL (usually the query string) is longer than the server will accept. |
| 503 |
HTTP 503 Service Unavailable |
The server is temporarily unable to handle the request — overloaded, in maintenance, or has no healthy backen… |
| 429 |
HTTP 429 Too Many Requests |
You’ve hit a rate limit — too many requests in a given time window. Slow down and retry later. |
| 408 |
HTTP 408 Request Timeout |
The server closed the connection because the client took too long to send the complete request. |
| 301 |
HTTP 301 Moved Permanently |
The resource has a new permanent URL; clients and search engines should use the address in the Location heade… |
| 302 |
HTTP 302 Found (Temporary Redirect) |
The resource is temporarily at another URL; clients should keep using the original URL for future requests. |
| 421 |
HTTP 421 Misdirected Request |
The request reached a server that isn’t configured for that host name — usually HTTP/2 connection reuse acros… |
| 495 |
Nginx 400: The SSL certificate error (495 / 496 client certificate) |
Nginx rejected the request because the client certificate was invalid (495) or missing (496) on a site that r… |
| 497 |
400 Bad Request: The plain HTTP request was sent to HTTPS port (Nginx 497) |
Plain http:// traffic arrived on a port Nginx expects to be TLS (443 or a custom SSL port). |
| 100 |
HTTP 100 Continue |
An interim response telling the client to go ahead and send the request body — normal when the client sent Ex… |
| 103 |
HTTP 103 Early Hints |
An interim response that sends Link headers early so the browser can preload CSS, fonts or scripts while the… |
| 303 |
HTTP 303 See Other |
A redirect telling the client to fetch the result from another URL with GET — used after a form POST so refre… |
| 401 |
HTTP 401 Unauthorized |
The request has no valid authentication credentials — you need to log in or send a valid token. |
| 411 |
HTTP 411 Length Required |
The server refuses a request with a body but no Content-Length header. |
| 304 |
HTTP 304 Not Modified |
The cached copy is still valid, so the server sends no body and the client reuses its cache. |
| 407 |
HTTP 407 Proxy Authentication Required |
A proxy between you and the server requires credentials before it will forward your request. |
| 409 |
HTTP 409 Conflict |
The request conflicts with the current state of the resource — e.g. a duplicate or an edit based on an outdat… |
| 307 |
HTTP 307 Temporary Redirect |
A temporary redirect that keeps the original method and body — a POST stays a POST at the new URL. |
| 402 |
HTTP 402 Payment Required |
The service wants payment before it will process the request — an unpaid invoice, exhausted credits or a fail… |
| 417 |
HTTP 417 Expectation Failed |
The server or a proxy can’t meet the Expect header in the request — almost always Expect: 100-continue. |
| 418 |
HTTP 418 I'm a teapot |
An April Fools’ status from RFC 2324 — some sites and WAFs return it on purpose to tell bots or scrapers to g… |
| 431 |
HTTP 431 Request Header Fields Too Large |
The request headers — almost always cookies — exceed the server’s size limit. |
| 502 |
HTTP 502 Bad Gateway |
A proxy or gateway (Nginx, load balancer, CDN) got an invalid response — or no response — from the upstream s… |
| 504 |
HTTP 504 Gateway Timeout |
A proxy or gateway waited too long for the upstream server to respond and gave up. |
| 444 |
Nginx 444 No Response (connection closed without response) |
An Nginx-specific code: the server deliberately closed the connection without sending anything — a rule is dr… |
| 410 |
HTTP 410 Gone |
The resource used to exist but was intentionally and permanently removed, with no forwarding address. |
| 416 |
HTTP 416 Range Not Satisfiable |
The client asked for a byte range (Range: bytes=…) that lies outside the file — usually a resumed download of… |
| 424 |
HTTP 424 Failed Dependency |
The request failed because another action it depended on failed — part of a WebDAV multi-step operation or a… |
| 508 |
HTTP 508 Loop Detected (Resource Limit Is Reached) |
Either the server detected an infinite loop (WebDAV) or — much more often — a cPanel/CloudLinux host is sayin… |
| 509 |
HTTP 509 Bandwidth Limit Exceeded |
A hosting-control-panel status (cPanel/Apache) meaning the account used up its monthly bandwidth allowance. |
| 308 |
HTTP 308 Permanent Redirect |
A permanent redirect that, unlike 301, guarantees the method and body are kept. |
| 406 |
HTTP 406 Not Acceptable |
The server can’t produce a response in any format listed in the request’s Accept headers. |
| 415 |
HTTP 415 Unsupported Media Type |
The server refuses the request because the body’s Content-Type isn’t one it accepts. |
| 451 |
HTTP 451 Unavailable For Legal Reasons |
The content is blocked for legal reasons — a court order, government censorship, sanctions, or GDPR geo-block… |
| 501 |
HTTP 501 Not Implemented |
The server doesn’t support the functionality (usually the HTTP method) needed to fulfil the request. |
| 423 |
HTTP 423 Locked |
The resource is locked, so the change was refused — common with WebDAV files and some APIs that lock records… |
| 499 |
HTTP 499 Client Closed Request (Nginx) |
Nginx-specific code logged when the client disconnected before the server finished responding. |
| 505 |
HTTP 505 HTTP Version Not Supported |
The server doesn’t support the HTTP protocol version used in the request. |
| 507 |
HTTP 507 Insufficient Storage |
The server can’t store what’s needed to complete the request — the disk, quota or mailbox is full. |
| 511 |
HTTP 511 Network Authentication Required |
A captive portal (hotel, airport, office Wi-Fi) is intercepting your traffic until you log in or accept its t… |
| 405 |
HTTP 405 Method Not Allowed |
The URL exists, but it doesn’t accept the HTTP method you used (e.g. POST to a GET-only route). |
| 412 |
HTTP 412 Precondition Failed |
A conditional request header (If-Match, If-Unmodified-Since) didn’t match the current state of the resource. |
| 413 |
HTTP 413 Content Too Large (Request Entity Too Large) |
The request body is bigger than the server is willing to accept — usually a file upload over the configured l… |
| 506 |
HTTP 506 Variant Also Negotiates |
The server encountered an internal configuration error because the requested resource is configured to use tr… |
| 428 |
HTTP 428 Precondition Required |
The server requires a conditional request (If-Match / If-Unmodified-Since) to prevent lost updates, and you d… |