GoKawiilCloudflare adds Vary header support to Cache Rules across all plans
Cloudflare has launched support for the HTTP Vary response header within its Cache Rules feature, available to customers on every service tier. The update lets origin servers specify which request headers may affect a response, while giving Cloudflare customers control over how those variations are handled in caching—whether by normalizing header values, preserving exact values, or bypassing the cache entirely.
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Vary has long been considered one of HTTP's messiest mechanisms because treating every header variation as distinct can fragment a cache into thousands of near-duplicate entries, while ignoring it risks serving wrong content to users. By letting customers decide how much variation actually matters, Cloudflare's approach could improve cache efficiency for sites serving different languages, formats, or regional content from the same URL. This suggests Cloudflare is positioning itself to handle content negotiation more precisely than a blanket accept-or-ignore approach to the header.
- Vary header support in Cache Rules is now available to all Cloudflare plans, not just enterprise customers.
- Customers can choose how Cloudflare treats varying headers: normalize, pass through exact values, or bypass cache.
- The feature addresses a longstanding tension between cache efficiency and serving correct content across intermediaries.
Source: blog.cloudflare.com, 2026-09-23
Published there as: “We just shipped support for the ugliest part of HTTP: Vary – Cloudflare Blog”
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