If the query variable ?compress=RESPONSE_COMPRESSION is present in the request URL, the server's response will be compressed.

RESPONSE_COMPRESSION can be:

• identity: no compression is performed
• deflate or gzip: common compression algorithms supported by most browsers
• brotli: best compression algorithms supported by modern browsers only

By default, no compression is performed.

Only textual content is compressed. Binary content, including pictures and video, is never compressed.

Request compression

It is possible to specify that the request payload is compressed by adding a second compression algorithm to the compress query variable, i.e. by using ?compress=RESPONSE_COMPRESSION,REQUEST_COMPRESSION, for example ?compress=gzip,gzip.

Note that while most web clients (including browsers) automatically decompress responses, almost none of them compress the request payload. This means, in order to use request compression, the request payload must usually be manually compressed by the client application before sending.

HTTP headers

HTTP can also use the standard headers Accept-Encoding and Content-Encoding instead of the compress query variable