MockFoxAdvertise

HTTP 423 Locked

Updated Free mock REST & WebSocket APIs

HTTP 423 Locked — The resource is locked and can't be modified right now.

Class
4xx Client Error
Defined in
RFC 4918 (WebDAV)
Official
Yes (IANA registry)
Cacheable by default
No (unless Cache-Control/Expires say so)
Safe to retry
Not without changing the request

Try it: get a real 423 response

Our test endpoint answers every request with 423 Locked.

curl -i https://mockfox.dev/api/status/423

Use it in tests, health-check monitors or to see how your client handles a 423. Add ?delay=2000 to slow it down.

What does HTTP 423 mean?

A WebDAV status for resources locked by another client (via the LOCK method) — for example a document open for editing in Word through SharePoint. The client should wait or submit the lock token in an If header. Some APIs reuse 423 for accounts temporarily locked after failed logins.

How to fix 423

  1. Visitors: Reload the page, check the address for typos, and clear the site's cookies. If it persists, the site owner needs to fix it.
  2. Developers: Read the response body and server logs for details, fix the request (method, headers, body, credentials) and return a clear error message to clients.

Example 423 response

HTTP/1.1 423 Locked
Content-Type: application/json

{"status":423,"error":"Locked"}

4xx Client Error: The request contains an error or can't be fulfilled — fix the request before retrying. See the full list of HTTP status codes.

Related status codes

Related tools

Frequently asked questions

What does HTTP 423 Locked mean?

The resource is locked and can't be modified right now.

Is 423 a client or a server error?

423 is a 4xx code, so it signals a problem with the request (as seen by the server). Retrying the identical request usually gives the same result.

Where is 423 defined?

In RFC 4918 (WebDAV). It's listed in the IANA HTTP Status Code Registry.

How can I test how my app handles a 423?

Call https://mockfox.dev/api/status/423 — it responds with 423 to any method, with CORS enabled. Add ?delay=2000 to simulate a slow response.