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|
Retry-After: <http-date> Retry-After: <delay-seconds>
- A date after which to retry. See the
Dateheader for more details on the HTTP date format.
- A non-negative decimal integer indicating the seconds to delay after the response is received.
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 send 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
|RFC 7231, section 7.1.3: Retry-After||Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content|
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||Android webview||Chrome for Android||Edge mobile||Firefox for Android||IE mobile||Opera Android||iOS Safari|
1. See Bug 230260.
- Google Webmaster blog: How to deal with planned site downtime