Cache-Control HTTP Header

Cache-Control

Inform all caching mechanisms from server to client whether they may cache this object.

Accepted Values

Multiple options from the list below are allowed, each seperated by a comma. Some options take a value, and that is preceded with an = after the option.

immutable: Response will not change.
max-age=<integer>: The time a browser should remember a site can only be accessed with https (seconds).
max-age=4
max-stale=<integer>: Client will accept stale responses (seconds).
max-stale=4
min-fresh=<integer>: Client wants a response that will be fresh for the given time (seconds).
min-fresh=4
must-revalidate: Stale caches must not be used.
no-cache: May be stored by any cache but must be validated by the server.
no-store: May not be stored by any cache.
no-transform: Intermediate cache or proxy cannot modify the response or certain headers.
only-if-cached: Do not use the network for responses.
private: May only be stored by a browser cache.
proxy-revalidate: Stale shared caches must no be used.
public: May be stored by any cache.
s-maxage=<integer>: Override max-age for shared caches, ignored by private caches.
s-maxage=4
stale-if-error=<integer>: Client will accept a stale response if the check for a fresh one fails (seconds).
stale-if-error=4
stale-while-revalidate=<integer>: Client will accept a stale response and will check for a fresh one (seconds).
stale-while-revalidate=4

Example

Cache-Control: public, private, max-age=4, s-maxage=4

Parse

Enter a Cache-Control header below to parse and return details about it.

Reference

https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cache-Control