index.md

---

title: Access-Control-Max-Age
slug: Web/HTTP/Headers/Access-Control-Max-Age
browser-compat: http.headers.Access-Control-Max-Age

---

{{HTTPSidebar}}

The Access-Control-Max-Age 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 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")}}