| [ Web Proxy ] |
| Viewing: https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Status/504 | [Back] [Original] |
Get to know MDN better
The HTTP 504 Gateway Timeout server error response status code indicates that the server, while acting as a gateway or proxy, did not get a response in time from the upstream server in order to complete the request.
This is similar to a 502 Bad Gateway, except that in a 504 status, the proxy or gateway did not receive any HTTP response from the origin within a certain time.
There are many causes of 504 errors, and fixing such problems likely requires investigation and debugging by server administrators, or the site may work again at a later time.
Exceptions are client networking errors, particularly if the service works for other visitors, and if clients use VPNs or other custom networking setups.
In such cases, clients should check network settings, firewall setup, proxy settings, DNS configuration, etc.
504 Gateway Timeout
The following request tries to fetch a webpage, but receives a 504 response in return.
The response body contains a page describing the server state with a link to a support page for visitors.
GET /highlights HTTP/1.1
Host: example.com
User-Agent: curl/8.6.0
Accept: */*
HTTP/1.1 504 Gateway Timeout
Content-Type: text/html;
Content-Length: 123
<!doctype html>
<html lang="en">
<head>
<title>504 Gateway Timeout</title>
</head>
<body>
<h1>Gateway timeout</h1>
<p>The server did not respond in time. Please try again later.</p>
<p>If this problem persists, please <a href="https://example.com/support">contact support</a>.</p>
</body>
</html>
| Specification |
|---|
| HTTP Semantics # status.504 |
This page was last modified on Jun 22, 2026 by MDN contributors.
Reason: CORS disabledReason: CORS header 'Access-Control-Allow-Origin' does not match 'xyz'Reason: CORS header 'Access-Control-Allow-Origin' missingReason: CORS header 'Origin' cannot be addedReason: CORS preflight channel did not succeedReason: CORS request did not succeedReason: CORS request external redirect not allowedReason: CORS request not HTTPReason: Credential is not supported if the CORS header 'Access-Control-Allow-Origin' is '*'Reason: Did not find method in CORS header 'Access-Control-Allow-Methods'Reason: expected 'true' in CORS header 'Access-Control-Allow-Credentials'Reason: invalid token 'xyz' in CORS header 'Access-Control-Allow-Headers'Reason: invalid token 'xyz' in CORS header 'Access-Control-Allow-Methods'Reason: missing token 'xyz' in CORS header 'Access-Control-Allow-Headers' from CORS preflight channelReason: Multiple CORS header 'Access-Control-Allow-Origin' not allowedAcceptAccept-CHAccept-EncodingAccept-LanguageAccept-PatchAccept-PostAccept-RangesAccess-Control-Allow-CredentialsAccess-Control-Allow-HeadersAccess-Control-Allow-MethodsAccess-Control-Allow-OriginAccess-Control-Expose-HeadersAccess-Control-Max-AgeAccess-Control-Request-HeadersAccess-Control-Request-MethodActivate-Storage-AccessAgeAllowAlt-SvcAlt-UsedAttribution-Reporting-EligibleAttribution-Reporting-Register-SourceAttribution-Reporting-Register-TriggerAuthorizationAvailable-DictionaryCache-ControlClear-Site-DataConnectionContent-DigestContent-DispositionContent-DPRContent-EncodingContent-LanguageContent-LengthContent-LocationContent-RangeContent-Security-PolicyContent-Security-Policy-Report-OnlyContent-TypeCookieCritical-CHCross-Origin-Embedder-PolicyCross-Origin-Embedder-Policy-Report-OnlyCross-Origin-Opener-PolicyCross-Origin-Resource-PolicyDateDevice-MemoryDictionary-IDDNTDownlinkDPREarly-DataECTETagExpectExpect-CTExpiresForwardedFromHostIdempotency-KeyIf-MatchIf-Modified-SinceIf-None-MatchIf-RangeIf-Unmodified-SinceIntegrity-PolicyIntegrity-Policy-Report-OnlyKeep-AliveLast-ModifiedLinkLocationMax-ForwardsNELNo-Vary-SearchObserve-Browsing-TopicsOriginOrigin-Agent-ClusterPermissions-PolicyPermissions-Policy-Report-OnlyPragmaPreferPreference-AppliedPriorityProxy-AuthenticateProxy-AuthorizationRangeRefererReferrer-PolicyRefreshReport-ToReporting-EndpointsRepr-DigestRetry-AfterRTTSave-DataSec-Browsing-TopicsSec-CH-Device-MemorySec-CH-DPRSec-CH-Prefers-Color-SchemeSec-CH-Prefers-Reduced-MotionSec-CH-Prefers-Reduced-TransparencySec-CH-UASec-CH-UA-ArchSec-CH-UA-BitnessSec-CH-UA-Form-FactorsSec-CH-UA-Full-VersionSec-CH-UA-Full-Version-ListSec-CH-UA-MobileSec-CH-UA-ModelSec-CH-UA-PlatformSec-CH-UA-Platform-VersionSec-CH-UA-WoW64Sec-CH-Viewport-HeightSec-CH-Viewport-WidthSec-CH-WidthSec-Fetch-DestSec-Fetch-ModeSec-Fetch-SiteSec-Fetch-Storage-AccessSec-Fetch-UserSec-GPCSec-Private-State-TokenSec-Private-State-Token-Crypto-VersionSec-Private-State-Token-LifetimeSec-PurposeSec-Redemption-RecordSec-Speculation-TagsSec-WebSocket-AcceptSec-WebSocket-ExtensionsSec-WebSocket-KeySec-WebSocket-ProtocolSec-WebSocket-VersionServerServer-TimingService-WorkerService-Worker-AllowedService-Worker-Navigation-PreloadSet-CookieSet-LoginSourceMapSpeculation-RulesStrict-Transport-SecuritySupports-Loading-ModeTETiming-Allow-OriginTkTrailerTransfer-EncodingUpgradeUpgrade-Insecure-RequestsUse-As-DictionaryUser-AgentVaryViaViewport-WidthWant-Content-DigestWant-Repr-DigestWarningWidthWWW-AuthenticateX-Content-Type-OptionsX-DNS-Prefetch-ControlX-Forwarded-ForX-Forwarded-HostX-Forwarded-ProtoX-Frame-OptionsX-Permitted-Cross-Domain-PoliciesX-Powered-ByX-Robots-TagX-XSS-Protection100 Continue101 Switching Protocols102 Processing103 Early Hints200 OK201 Created202 Accepted203 Non-Authoritative Information204 No Content205 Reset Content206 Partial Content207 Multi-Status208 Already Reported226 IM Used300 Multiple Choices301 Moved Permanently302 Found303 See Other304 Not Modified307 Temporary Redirect308 Permanent Redirect400 Bad Request401 Unauthorized402 Payment Required403 Forbidden404 Not Found405 Method Not Allowed406 Not Acceptable407 Proxy Authentication Required408 Request Timeout409 Conflict410 Gone411 Length Required412 Precondition Failed413 Content Too Large414 URI Too Long415 Unsupported Media Type416 Range Not Satisfiable417 Expectation Failed418 I'm a teapot421 Misdirected Request422 Unprocessable Content423 Locked424 Failed Dependency425 Too Early426 Upgrade Required428 Precondition Required429 Too Many Requests431 Request Header Fields Too Large451 Unavailable For Legal Reasons500 Internal Server Error501 Not Implemented502 Bad Gateway503 Service Unavailable504 Gateway Timeout505 HTTP Version Not Supported506 Variant Also Negotiates507 Insufficient Storage508 Loop Detected510 Not Extended511 Network Authentication Requiredbase-uriblock-all-mixed-contentchild-srcconnect-srcdefault-srcfenced-frame-srcfont-srcform-actionframe-ancestorsframe-srcimg-srcmanifest-srcmedia-srcobject-srcprefetch-srcreport-toreport-urirequire-trusted-types-forsandboxscript-srcscript-src-attrscript-src-elemstyle-srcstyle-src-attrstyle-src-elemtrusted-typesupgrade-insecure-requestsworker-srcaccelerometerambient-light-sensoraria-notifyattribution-reportingautoplaybluetoothbrowsing-topicscameracaptured-surface-controlch-ua-high-entropy-valuescompute-pressurecross-origin-isolateddeferred-fetchdeferred-fetch-minimaldisplay-captureencrypted-mediafullscreengamepadgeolocationgyroscopehididentity-credentials-getidle-detectionlanguage-detectorlanguage-modellocal-fontslocal-networklocal-network-accessloopback-networkmagnetometermicrophonemidion-device-speech-recognitionotp-credentialspaymentpicture-in-pictureprivate-state-token-issuanceprivate-state-token-redemptionpublickey-credentials-createpublickey-credentials-getscreen-wake-lockserialspeaker-selectionstorage-accesssummarizertranslatorusbweb-sharewindow-managementxr-spatial-trackingYour blueprint for a better internet.
Portions of this content are 19982026 by individual mozilla.org contributors. Content available under a Creative Commons license.
| Web Proxy Viewer | New URL | Original Page |