The Ultimate Guide to HTTP Status Codes (100–599)
A complete reference guide to all HTTP status codes from 100 to 599, with explanations and common use cases.
Feb 28, 2026
423
HTTP 423 Locked
4xx Client Error
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4xx Client Error
RFC 4918, Section 11.3
What is HTTP 423 Locked?
The 423 (Locked) status code indicates that the source or destination resource of a method is locked. This is used in WebDAV to prevent modifications to a resource that is currently locked by another user.
Common Use Cases
- WebDAV resource locking
- Collaborative editing conflicts
Usage Example
In a WebDAV-based document management system, when a user tries to modify a file that another user has locked, the server responds with 423 Locked. The response should include information about who holds the lock and when it was acquired.
<?xml version="1.0" encoding="utf-8"?>
<d:error xmlns:d="DAV:">
<d:lock-token-submitted>
<d:href>/locks/abc123</d:href>
</d:lock-token-submitted>
</d:error>Related Status Codes
Last updated: 17 Aug 2026