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 HTTP 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 request header | No |
Syntax
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. Firefox 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). The default value is 5 seconds.
Examples
Cache results of a preflight request for 10 minutes:
Access-Control-Max-Age: 600
Specifications
| Specification |
|---|
| Fetch # http-access-control-max-age |
Browser compatibility
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