Cache-Control Header Builder

Build a valid HTTP Cache-Control header by selecting directives. The resulting value is ready to copy into a server config, .htaccess, or CDN rule.

Quick presets

Preset	Header value	Use case
Immutable asset	`public, max-age=31536000, immutable`	Fingerprinted JS/CSS/images (cache forever)
HTML page	`no-cache`	Dynamic pages, always revalidate before serving
API / dynamic	`private, no-store`	Personalized responses (user data, tokens)
No cache	`no-store, no-cache, must-revalidate`	Maximum freshness enforcement

Key directive explanations

public: the response can be cached by any cache (browser, CDN, proxy)
private: only the browser can cache; CDNs and shared caches must not
no-cache: the cached copy must be revalidated with the server on every request (not "no caching": the name is misleading)
no-store: never cache, never store on disk. For sensitive data.
max-age=N: the response is fresh for N seconds; the browser serves it directly without hitting the server
immutable: tells the browser the resource will never change for the duration of max-age; prevents conditional requests
must-revalidate: once stale, the cache must not serve the stale copy; it must revalidate or fail

Caching strategy guide

The most effective caching strategy combines long-lived caching for fingerprinted assets (immutable) with short or no caching for HTML documents. This way, deploying a new version with new asset filenames forces browsers to fetch fresh assets, while the HTML is always current.