Access-Control-Max-Age
{{HTTPSidebar}}
The HTTP Access-Control-Max-Age
{{Glossary("response header")}}
indicates how long the results of a {{glossary("preflight request")}}
(that is, the information contained in the {{HTTPHeader("Access-Control-Allow-Methods")}}
and {{HTTPHeader("Access-Control-Allow-Headers")}}
headers) can be cached.
Header type | `{{Glossary("Response header")}}` |
---|---|
`{{Glossary("Forbidden header name")}}` | 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
{{Specifications}}
Browser compatibility
{{Compat}}
See also
{{HTTPHeader("Access-Control-Allow-Headers")}}
{{HTTPHeader("Access-Control-Allow-Methods")}}