We just shipped support for the ugliest part of HTTP: Vary – Cloudflare Blog
3 hours ago
- Cloudflare now supports the Vary response header in Cache Rules on all plans.
- Vary tells caches which request headers may affect the response, but caches must decide which differences actually matter.
- High-cardinality variations can fragment caches, reducing hit ratios and increasing origin load.
- Cloudflare offers three actions for each Vary header: normalize, passthrough, and bypass.
- Normalize is recommended for negotiation headers to collapse equivalent requests into shared cache entries.
- Passthrough preserves exact header values for cases where small differences change the response.
- Bypass is used for personalized or unpredictable headers, preventing the response from being cached.
- Configuration is available via dashboard, Rulesets API, and Terraform.
- Custom cache keys apply to all responses, while Vary is response-driven and more precise.
- The feature is available on Free, Pro, Business, and Enterprise plans.