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Compression dictionary transport with Shared Brotli and Shared Zstandard

Category
Network / Connectivity
Type
New or changed feature
Status
Enabled by default (Chrome 130)
Intent stage
None

Summary

This feature adds support for using designated previous responses, as an external dictionary for content encoding compressing responses with Brotli or Zstandard. Enterprises might experience potential compatibility issues with enterprise network infrastructure that intercepts HTTPS traffic and is sensitive to unknown content encodings. The enterprise policy "CompressionDictionaryTransportEnabled" is available to turn off the compression dictionary transport feature.

Motivation

If the browser and server share a dictionary, using the dictionary for compression can significantly reduce the amount of data transferred. This is especially useful for incremental library updates, or when browsing multiple pages that have a lot of common parts in their files.

Standards & signals

Docs: https://docs.google.com/document/d/1IcRHLv-e9boECgPA5J4t8NDv9FPHDGgn0C12kfBgANg/edit https://github.com/WICG/compression-dictionary-transport https://datatracker.ietf.org/doc/draft-ietf-httpbis-compression-dictionary https://docs.google.com/document/d/1WCK965Ew0hTN6k05o2JFi9Y-AdGfkB1io_i6LrTSeQs/edit?usp=sharing

Samples: https://compression-dictionary-transport-threejs-demo.glitch.me https://compression-dictionary-transport-shop-demo.glitch.me

Explainers: https://github.com/WICG/compression-dictionary-transport

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