HTTP 508 Loop Detected: Causes and Fixes

What HTTP 508 means

Defined for WebDAV operations on collections with circular bindings. Some hosting providers also show 508 “Resource Limit Is Reached” when an account exceeds its CPU or process limits.

Retrying

Rarely. The server can’t handle this request, so retrying it unchanged is unlikely to help.

Example response

HTTP/1.1 508 Loop Detected
Date: Wed, 21 Oct 2026 10:30:00 GMT
Content-Type: application/json

How to return 508

Node.js (Express)

res.status(508).json({ error: 'Loop Detected' });

Python (FastAPI)

from fastapi import HTTPException

raise HTTPException(status_code=508, detail="Loop Detected")

Go (net/http)

http.Error(w, http.StatusText(http.StatusLoopDetected), http.StatusLoopDetected)

nginx

location /private/ {
    return 508;
}

Related status codes

500 Internal Server Error : The server hit an unexpected error and couldn’t complete the request.
503 Service Unavailable : The server is temporarily unable to handle requests, usually overload or maintenance.

Other 5xx status codes

500 Internal Server Error · 501 Not Implemented · 502 Bad Gateway · 503 Service Unavailable · 504 Gateway Timeout · 505 HTTP Version Not Supported · 507 Insufficient Storage · 511 Network Authentication Required · 520 Web Server Returned an Unknown Error · 521 Web Server Is Down · 522 Connection Timed Out · 523 Origin Is Unreachable · 524 A Timeout Occurred · 525 SSL Handshake Failed · 526 Invalid SSL Certificate

See the full list of HTTP status codes.

Sources

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Frequently asked questions

What does HTTP 508 Loop Detected mean?

HTTP 508 Loop Detected means the server found an infinite loop while processing the request (WebDAV). Defined for WebDAV operations on collections with circular bindings. Some hosting providers also show 508 “Resource Limit Is Reached” when an account exceeds its CPU or process limits.