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Retry-After header

files/en-us/web/http/reference/headers/retry-after/index.md

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The HTTP Retry-After {{Glossary("response header")}} indicates how long the user agent should wait before making a follow-up request. There are three main cases this header is used:

  • In a {{HTTPStatus("503", "503 Service Unavailable")}} response, this indicates how long the service is expected to be unavailable.
  • In a {{HTTPStatus("429", "429 Too Many Requests")}} response, this indicates how long to wait before making a new request.
  • In a redirect response, such as {{HTTPStatus("301", "301 Moved Permanently")}}, this indicates the minimum time that the user agent is asked to wait before issuing the redirected request.
<table class="properties"> <tbody> <tr> <th scope="row">Header type</th> <td>{{Glossary("Response header")}}</td> </tr> </tbody> </table>

Syntax

http
Retry-After: <http-date>
Retry-After: <delay-seconds>

Directives

  • <http-date>
    • : A date after which to retry. See the {{HTTPHeader("Date")}} header 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 send it along with a 503 response, so that search engines will keep indexing your site when the downtime is over.

http
Retry-After: Wed, 21 Oct 2015 07:28:00 GMT
Retry-After: 120

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also