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HTTP Status Code

508 Loop Detected

Server Error

The server detected an infinite loop while processing the request.

HTTP status code reference, response example, common causes, fixes, and related status codes.

What does HTTP 508 Loop Detected mean?

HTTP 508 Loop Detected is a status code sent by a server to indicate the result of an HTTP request.

Status codes help browsers, APIs, apps, and backend systems understand whether a request succeeded, failed, was redirected, or needs additional action.

In practice, HTTP 508 Loop Detected usually appears when a server responds under specific request, validation, permission, or infrastructure conditions.

Response example

HTTP/1.1 508 Loop Detected

HTTP example

HTTP/1.1 508 Loop Detected

Common causes

  • Circular reference in a WebDAV directory structure
  • Infinite binding loop detected during PROPFIND depth traversal
  • Recursive resource dependencies on the server side

How to fix it

  • Inspect and resolve circular references in the resource structure
  • Avoid creating DAV bindings that reference parent collections
  • Check server-side logic for unintended recursive processing

Common mistakes

  • Assuming the status code alone explains the full backend issue
  • Ignoring related response headers that add important context
  • Treating temporary errors as permanent failures
  • Retrying too aggressively without checking the cause
  • Debugging the frontend only when the problem is server-side

How browsers and APIs use it

Browsers, APIs, and backend services use HTTP status codes to understand the outcome of a request. Depending on the status code, an application may render content, retry a request, redirect the user, show an error, or trigger a different flow in the client or server.

Practical developer insight

508 Loop Detected is defined in RFC 5842 for WebDAV. It signals that the server aborted a request because it detected an infinite loop, typically during deep traversal of a collection with circular bindings. Not relevant outside WebDAV and similar systems.

Related status codes