The Access-Control-Max-Age response header indicates how long the results of a preflight request (that is the information contained in the Access-Control-Allow-Methods and Access-Control-Allow-Headers headers) can be cached.

Header type Response header
Forbidden header name no


Access-Control-Max-Age: <delta-seconds>


Maximum number of seconds the results can be cached.
UXP caps this at 24 hours (86400 seconds).
Chromium (prior to v76) caps at 10 minutes (600 seconds).
Chromium (starting in v76) caps at 2 hours (7200 seconds).
Chromium also specifies a default value of 5 seconds.
A value of -1 will disable caching, requiring a preflight OPTIONS check for all calls.


Cache results of a preflight request for 10 minutes:

Access-Control-Max-Age: 600 


Specification Status Comment
The definition of 'Access-Control-Max-Age' in that specification.
Living Standard Initial definition.

Browser compatibility

ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
Access-Control-Max-AgeChrome Full support 4Edge Full support 12Firefox Full support 3.5IE Full support 10Opera Full support 12Safari Full support 4WebView Android Full support 2Chrome Android Full support YesFirefox Android Full support 4Opera Android Full support 12Safari iOS Full support 3.2Samsung Internet Android Full support Yes


Full support
Full support

See also