Compression Dictionary Transport

Compression Dictionary Transport is a way of using a shared compression dictionary, rather than the standard static dictionary in {{glossary("Brotli compression")}} or {{glossary("Zstandard compression")}}, to dramatically reduce the transport size of HTTP responses.

For example, when downloading app.v2.js, if the client already has app.v1.js then they can reference text from that by using it as a dictionary and effectively only download the delta and a small amount of references to the v1 file.

See the Compression Dictionary Transport guide for more information.

See also

• Compression Dictionary Transport guide
• Related glossary terms:
  • {{Glossary("Brotli compression")}}
  • {{Glossary("Zstandard compression")}}
• <link rel="compression-dictionary">
• {{HTTPHeader("Accept-encoding")}}
• {{HTTPHeader("Content-encoding")}}
• {{HTTPHeader("Available-Dictionary")}}
• {{HTTPHeader("Dictionary-ID")}}
• {{HTTPHeader("Use-As-Dictionary")}}
• Draft specification