HTTP Cache Planner

Build or explain Cache-Control headers with TTL math and practical browser/CDN guidance.

Quick samples

Choose your workflow

Start from a practical recipe and tune browser/CDN behavior before implementation.

Plan the policy

Tune browser and shared-cache behavior with a recipe-first form.

Long-lived immutable files such as hashed JS or CSS bundles.

`max-age` in seconds for browser caches.

`s-maxage` in seconds for CDNs and other shared caches.

Optional background-refresh window in seconds.

Optional origin-failure fallback window in seconds.

Turn this on only when the URL changes whenever the file contents change.

Your cache policy

Build a policy or explain an existing header to get a copy-ready result.

No cache policy yet

Start with a recipe or paste a Cache-Control value to see the final header, how it behaves, and what else you need to implement it well.

Documentation

HTTP Cache Planner

Full Docs

About this tool

HTTP Cache Planner builds Cache-Control policies or explains pasted cache headers. Use it when planning browser and CDN caching behavior or reviewing a live policy.

Modes

Build mode starts from response-type recipes and lets you adjust freshness and stale windows.

Explain mode parses a raw Cache-Control value or full header line and turns it into readable timing guidance.

info

Gotchas

Use immutable only for versioned URLs that change when the content changes.

Avoid mixing private-response intent with shared-cache behavior unless that is truly intended.

tips_and_updates

Key use cases

  • -Choose a cache policy for assets, HTML, APIs, or private content.
  • -Explain a pasted Cache-Control header.
  • -Compare browser and shared-cache TTLs.
  • -Review companion headers like ETag, Last-Modified, Expires, and Vary.

FAQ