Client Error · 4xx

423 Locked

The resource is locked and cannot be modified right now.

What 423 Locked means

423 Locked is a WebDAV code for resource-level locking. Some non-WebDAV APIs use it to indicate temporary locks on resources during long-running operations (e.g. while a CI job is editing a config file, the file is locked). It is similar to 409 Conflict but specifically about explicit lock state, not state-mismatch in general.

When servers should return it: Return 423 when a resource has an explicit lock that prevents the requested operation.

Example response

HTTP/2 423
content-type: application/json
{"error":"resource locked","unlock_at":"2026-05-05T15:00:00Z"}

Related status codes

409
Conflict
425
Too Early
503
Service Unavailable

Frequently Asked Questions

Is 423 standard outside WebDAV?
Not really. Most REST APIs use 409 Conflict for locking. 423 is technically valid and somewhat self-documenting if your API has explicit locks.
Defined in: RFC 4918 · Class: 4xx Client Error

More references

For a one-page reference of all HTTP status codes, see the HTTP cheat sheet. For testing API responses, try the API Tester tool. For inspecting responses on the command line, the curl cheat sheet covers the most common flags.