We Just Shipped Support for the Ugliest Part of HTTP: Vary
Cloudflare, Tuesday, September 22nd, 2026
Cloudflare added Vary header support to Cache Rules on every plan, letting customers control how cached responses vary.
Cloudflare now supports the HTTP Vary response header in Cache Rules on every plan.
Vary tells a cache which request fields, like Accept or Accept-Language, may affect a response so it can serve the correct version, such as different image formats or languages from the same URL but it doesn't say which differences actually matter, and treating every header value as distinct can fragment a cache into thousands of barely reusable entries.
With the new support, customers can normalize known negotiation headers, pass exact values through to the origin when small differences matter, or bypass the cache entirely when variation is too unpredictable.