Access-Control-Max-Age

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

Syntax

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

Directives

<delta-seconds>

Maximum number of seconds 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 Standard (Fetch)
# http-access-control-max-age

Browser compatibility

BCD tables only load in the browser

See also