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. 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). 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


Fetch Standard (Fetch)
# http-access-control-max-age

Browser compatibility

BCD tables only load in the browser

See also