HTTP headers | Early-Data

HTTP headers | Retry-After

Last Updated : 22 Feb, 2023

HTTP headers are used to pass additional information with HTTP request or response. HTTP Retry-After header is an HTTP response header which indicates how long to wait before making another request. Depending on different status codes, there are different use cases of the Retry-After response header.

Status code 503: 503 is used to indicate service unavailable. Retry-After is used with 503 which tells the user how long the service is expected to be unavailable. It is used to deal with scheduled downtime.
Status code 301: 301 is used to indicate that resource is moved permanently. Retry-After is used with 301 which tells the user about the minimum for which user should wait before issuing the redirect request.
Status code 429: 429 id is used to indicate too many request. Retry-After is used with 429 to tells the user how long to wait before making another request.

Syntax:

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

Directives: This header accepts two directives as mentioned above and described below:

http-date: It indicated the date after which user should resend the request.
delay-seconds: It is an integer value indicating the no of seconds after which user should resend the request.

Example: This example will illustrates the HTTP Retry-After header:

Using date directive, after that date with the specified time client can retry the request.

Retry-After: Sun, 27 Oct 2019 09:45:00 GMT

Using delay-second directive, after that specified second client can retry the request.

Retry-After: 180

Supported Browsers: The browsers compatible with HTTP Retry-After header are listed below:

Google Chrome
Internet Explorer
Firefox
Safari
Opera

HTTP headers | Early-Data

aman neekhara

Improve

Article Tags :

Similar Reads

HTTP headers | Date

Description: HTTP headers are used to pass additional information with HTTP response or HTTP request. Date HTTP header contains the date and time at which the message was generated. It is supported by all the browsers. Syntax: Date: day-name, day month year hour:minute:second GMT Directives: day-nam

HTTP headers | Alt-Svc

The HTTP headers Alt-Svc header is a response-type header it has been used to advertise alternative service. Which services can be defined by a protocol/host/port combination. Syntax: Alt-Svc: clear Alt-Svc: <protocol-id>=<alt-authority>; ma=<max-age>; persist=1 Directives: This he

HTTP headers | Trailer

The HTTP Trailer header is a response header that indicates the given set of header fields is present in the trailer of a message encoded with chunked transfer-coding and allows the sender to include additional fields at the end of chunked messages in order to supply metadata. Syntax: Trailer: heade

HTTP headers | Keep-Alive

The Keep-Alive header is a general-type header. This header is used to hint at how the connection may be used to set a timeout and a maximum amount of requests. It can also be used to allow a single TCP connection to remain open for multiple HTTP requests/responses (default HTTP connection closed af

HTTP headers | Early-Data

The Early-Data header is a kind of HTTP header that permits clients to send requests immediately. This ensures that there are no one or two round-trip delays that are required by Transport Layer Security (TLS) handshake to get executed. When this header is set, it indicates that the request has been

HTTP headers | Tk

The HTTP Tk header is a response-type header it is used to indicates the tracking status that applied to the corresponding request. Syntax: Tk: ! (under construction) Tk: N (not tracking) Tk: T (tracking) Tk: C (tracking with consent) Tk: P (potential consent) Tk: D (disregarding DNT) Tk: U (updated

HTTP headers | Set-Cookie2

The HTTP Set-cookie2 is response type header and it is obsoleted. It is a provider of the mechanism to serve and retrieve state information from the client to the server. The usage of this command is usually replaced by the set cookie instead of the set cookie2. The usage of this command cookie2 is

HTTP headers | ETag

ETag or Entity Tag is a response-type header that works as a validator to let client make conditional requests. It makes re-validation requests more efficient by triggering request headers which help with web cache validation that makes economical use of network bandwidth. ETag is generated as ident

HTTP headers | expires

The HTTP Expires header is a response-type header, the fundamental way of controlling the caches present. The expire header contains the date and time which denotes the period where the object can stay alive. Once the period expires, the object becomes stale. Almost every client support expire heade

HTTP headers | Want-Digest

Before discussing about HTTP Want-Digest Header, let us first understand what is Digest (or message digest) ? HTTP header Digest is an encrypted fixed-size representation of a message generated using a hash function. A hash function can be any function that maps the data of arbitrary size to a fixed