Access-Control-Max-Age header
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
The HTTPAccess-Control-Max-Ageresponse header indicates how long the results of apreflight request (that is, the information contained in theAccess-Control-Allow-Methods andAccess-Control-Allow-Headers headers) can be cached.
| Header type | Response header |
|---|
Syntax
http
Access-Control-Max-Age: <delta-seconds>Directives
<delta-seconds>Maximum number of seconds for which the results can be cached as an unsigned non-negative integer.Firefoxcaps 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).The default value is 5 seconds.
Examples
Cache results of a preflight request for 10 minutes:
http
Access-Control-Max-Age: 600Specifications
| Specification |
|---|
| Fetch # http-access-control-max-age |