Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The Content-Digest response or request header provides a digest of the actual message content, the stream of octets framed in an HTTP message. As such, Content-Digest is dependent on among other things Content-Encoding and Content-Range, but not dependent on, for example, HTTP/1.1's Transfer-Encoding. Content-Digest may coincide with Repr-Digest if a representation was sent in a single message.

In this setting, content refers to a particular octet representation of the selected representation of the target resource.

A client can request that a server emit a Content-Digest by issuing Want-Content-Digest.

Header type Representation header
Forbidden header name no


Content-Digest describes an RFC8941 dictionary with its keys being names of digest algorithms and its values being the digest in bytes (or an integer digest for legacy digest algorithms).

Note: In contrast to earlier drafts of the specification, the standard-base64-encoded digest bytes are wrapped in colons (:, ASCII 0x3A) as part of the dictionary syntax.

Content-Digest: <digest-algorithm>=:<standard-padded-base64-digest-value>:, ...
Content-Digest: <digest-algorithm-integer-checksum>=<integer-checksum-value>, ...


For permissible digest algorithms see Repr-Digest.


Content-Digest: unixcksum=916142062
Content-Digest: md5=:+thA//8pGVGk2VYuJkFNvA==:, unixsum=26869


Unknown specification

Browser compatibility

BCD tables only load in the browser

See also