Free online tool

Cache-Control Header Builder

Build HTTP Cache-Control headers for browsers and shared caches

Caching policy

Preset

Who may cache it?

Browser freshness: max-age (seconds)

Shared-cache freshness: s-maxage (seconds)

Directives

no-store no-cache must-revalidate proxy-revalidate immutable

stale-while-revalidate (seconds)

stale-if-error (seconds)

no-cache permits storage but requires validation before reuse. no-store tells caches not to store the response.

HTTP header

PHP

Apache

Nginx

Fetch / service worker check

Build a Cache-Control header

Create a valid HTTP Cache-Control value and copy matching examples for PHP, Apache or Nginx. The timeline separates the fresh period from any explicitly allowed stale period.

Use long caching with immutable only for assets whose URL changes when their content changes, such as files containing a version or content hash. Personalized pages should normally be private, while sensitive responses may require no-store.