Accept-Ranges header

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

The HTTPAccept-Rangesresponse header is used by the server to advertise its support forrange requests, allowing clients to request part or several parts of a resource.The value of this header indicates the unit that can be used to define a range.

For example, a response with anAccept-Ranges header indicates that the server is capable ofresuming an interrupted download instead of a client restarting the transfer in full.

Header type	Response header

Syntax

http

Accept-Ranges: <range-unit>Accept-Ranges: none

Directives

<range-unit>: The range unit that the server supports, althoughbytes is the only range unit formally defined byRFC 7233.Range units are registered in theHTTP Range Unit Registry.
none: No range unit is supported.This is equivalent to omitting the header and is, therefore, rarely used.This value was used in legacy browsers to disable or remove the pause buttons in the download manager if servers had no support for range requests.