Content-Length

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 HTTP Content-Length header indicates the size, in bytes, of the message body sent to the recipient.

Header type Request header, Response header, Content header
Forbidden header name Yes
CORS-safelisted response header Yes

Syntax

http
Content-Length: <length>

Directives

<length>

The length in octets.

Specifications

Specification
HTTP Semantics
# field.content-length

Browser compatibility

Report problems with this compatibility data on GitHub
desktopmobile
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
Content-Length
CORS-safelisted response header

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support

See also