110 Response is Stale
The HTTP 110 Response is Stale warning code signals that a cached response has passed its freshness lifetime. The cache generates this code and attaches it to the Warning header in the HTTP response.
Example
Warning: 110 www.example.re "Response is Stale"
See also
- RFC 7234: HTTP Caching (obsoleted)
- RFC 9111: HTTP Caching
- Warning
- Cache-Status
- Caching
- HTTP status codes
Last updated: April 24, 2026