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Cache Response Rules

Cache Response Rules allow you to configure cache settings based on request and response attributes. These rules execute prior to caching in the http_response_cache_settings phase, which runs after Cloudflare receives the origin response.

With Cache Response Rules you can:

• Modify Cache-Control directives sent by your origin.
• Modify cache tags on responses for targeted cache purging.
• Strip headers (ETag, Set-Cookie, Last-Modified) from origin responses before caching.

Cache Response Rules apply to both cached and non-cached (dynamic) responses from the origin. For example, you can strip Set-Cookie headers from responses that are not eligible for caching.

Cache Response Rules can be created in the dashboard, via API, or Terraform.

The following table describes Cache Response Rules availability per plan.

When troubleshooting Cache Response Rules, use Cloudflare Trace to determine if a rule is triggering for a specific URL.

Cache Response Rules operate on the origin response, while Cache Rules operate on the incoming request. When settings from both rule types conflict, Cache Response Rules take precedence.

Key differences:

• Cache eligibility: Cache Rules remain the only mechanism to decide whether content is eligible for caching. However, Cache Response Rules can make a cacheable asset non-cacheable by setting the no-store directive using the set_cache_control action.
• Origin Cache Control (OCC): If any rule in the http_response_cache_settings phase matches, Cloudflare defaults to Origin Cache Control behavior (origin_cache_control = true).
• CDN-Cache-Control precedence: Cache-Control directives set by Cache Response Rules take precedence over origin-set Cloudflare-CDN-Cache-Control and CDN-Cache-Control headers. For more information, refer to CDN-Cache-Control header precedence.
• Stacking: Cache Response Rules stack the same way as Cache Rules. When multiple rules specify the same setting, the last matching rule wins.

Consider the following scenario:

1. A Cache Rule sets Edge TTL to override_origin with a value of 7200 seconds (2 hours).
2. A Cache Response Rule uses set_cache_control to set s-maxage to 3600 seconds (1 hour) with cloudflare_only enabled.
3. The origin responds with Cache-Control: s-maxage=600.

In this case, the Cache Response Rule takes precedence. Cloudflare caches the asset for 3600 seconds (1 hour) based on the s-maxage directive set by the Cache Response Rule, while visitors still receive the original s-maxage=600 from the origin because cloudflare_only is enabled.

Workers and Response Header Transform Rules execute after the caching decision has been made and cannot influence whether or how a response is cached. Only Cache Response Rules can modify caching behavior based on origin response headers.

If you need to override Cache-Control directives from the origin (for example, remove private or add s-maxage), use a Cache Response Rule — not a Worker or Transform Rule.

• If you strip last modified then Smart Edge Revalidation will be turned off.
• Cache Response Rules ignore 1xx HTTP response status codes as they are treated as informational responses.
• Cache Response Rules can be versioned. Refer to the Version Management documentation for more information.