HTTP 5xx Server Error Status Codes

HTTP Status Codes•Permalink

Server error responses like 500, 502, 503, and 504.

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Codes 500-510

Reference entries for HTTP 500-510 responses.

HTTP 500 Internal Server Error

Generic unexpected server failure

↗#

textANYhttpstatus-code5xxhttp-500

text

curl -i https://example.com/broken

Usually means the server failed while trying to fulfill a valid request.

HTTP 501 Not Implemented

Method or capability not implemented

↗#

textANYhttpstatus-code5xxhttp-501

text

curl -i -X PATCH https://example.com/legacy-endpoint

Used when the server does not support the functionality required to fulfill the request.

HTTP 502 Bad Gateway

Upstream sent invalid response

↗#

textANYhttpstatus-code5xxhttp-502

text

curl -i https://example.com/api

Common with reverse proxies when an upstream app returns malformed or unreachable responses.

HTTP 503 Service Unavailable

Temporarily unavailable or overloaded

↗#

textANYhttpstatus-code5xxhttp-503

text

curl -i https://example.com

Often used during maintenance windows or overload conditions.

HTTP 504 Gateway Timeout

Upstream did not respond in time

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textANYhttpstatus-code5xxhttp-504

text

curl -i https://example.com/reports

Typical when a proxy or gateway timed out waiting for an upstream service.

HTTP 505 HTTP Version Not Supported

HTTP version unsupported

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textANYhttpstatus-code5xxhttp-505

text

curl --http0.9 -i https://example.com

The server refuses the request due to the HTTP version used.

HTTP 506 Variant Also Negotiates

Negotiation config loop

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textANYhttpstatus-code5xxhttp-506

text

HTTP/1.1 506 Variant Also Negotiates

Indicates a server configuration error involving transparent content negotiation.

HTTP 507 Insufficient Storage

Server lacks storage to complete request

↗#

textANYhttpstatus-code5xxhttp-507

text

PUT /webdav/bigfile HTTP/1.1

Often associated with WebDAV or storage-limited operations.

HTTP 508 Loop Detected

Infinite loop detected while processing

↗#

textANYhttpstatus-code5xxhttp-508

text

PROPFIND /webdav/loop HTTP/1.1

Often seen in WebDAV processing graphs or recursive operations.

HTTP 510 Not Extended

Further request extensions required

↗#

textANYhttpstatus-code5xxhttp-510

text

HTTP/1.1 510 Not Extended

The server requires further extensions to fulfill the request.

Codes 511-511

Reference entries for HTTP 511-511 responses.

HTTP 511 Network Authentication Required

Network access authentication required

↗#

textANYhttpstatus-code5xxhttp-511

text

HTTP/1.1 511 Network Authentication Required

Typically indicates network-level auth, such as a captive portal.

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