The Retry-After response HTTP header indicates how long the user agent should wait before making a follow-up request. There are two main cases this header is used:
- When sent with a
503(Service Unavailable) response, it indicates how long the service is expected to be unavailable. - When sent with a redirect response, such as
301(Moved Permanently), it indicates the minimum time that the user agent is asked to wait before issuing the redirected request.
| Header type | Response header |
|---|---|
| Forbidden header name | no |
Syntax
Retry-After: <http-date> Retry-After: <delay-seconds>
Directives
- <http-date>
- A date after which to retry. See the
Dateheader for more details on the HTTP date format. - <delay-seconds>
- A non-negative decimal integer indicating the seconds to delay after the response is received.
Examples
Dealing with scheduled downtime
Support for the Retry-After header on both clients and servers is still inconsistent. However, some crawlers and spiders, like the Googlebot, honor the Retry-After header. It is useful to sent it along with a 503 (Service Unavailable) response, so that search engines will keep indexing your site when the downtime is over.
Retry-After: Wed, 21 Oct 2015 07:28:00 GMT Retry-After: 120
Specifications
| Specification | Title |
|---|---|
| RFC 7231, section 7.1.3: Retry-After | Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content |
Browser compatibility
The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
| Feature | Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | Servo |
|---|---|---|---|---|---|---|---|
| Retry-After | ? | ? | No support1 | ? | ? | ? | ? |
| Feature | Android | Chrome for Android | Edge Mobile | Firefox for Android | IE Mobile | Opera Mobile | Safari Mobile |
|---|---|---|---|---|---|---|---|
| Retry-After | ? | ? | ? | ? | ? | ? | ? |
1. See Bug 230260.
See also
- Google Webmaster blog: How to deal with planned site downtime
503(Service Unavailable)301(Moved Permanently)