Brotli

Brotli is an open source data compression library developed by Jyrki Alakuijala and Zoltán Szabadka.[1][2] Brotli is based on a modern variant of the LZ77 algorithm, Huffman coding and 2nd order context modeling.

It can be used to speed up browsing the Web in Chrome or Firefox.[3] Like zopfli, another compression algorithm from Google, brotli is named after a Swiss bakery product, brötli.[4]

About

Brotli was first released in 2015 for off-line compression of web fonts.[5] The version of Brotli released in September 2015 by the Google software engineers contained enhancements in generic lossless data compression, with particular emphasis on use for HTTP compression. The encoder was partly rewritten, with the result that the compression ratio improved, both the encoder and the decoder have been sped up, the streaming API was improved, more compression quality levels have been added. Additionally, the new release shows performance improvements across platforms, with decoding memory reduction.[4]

Unlike most general purpose compression algorithms, Brotli uses a pre-defined 120 kilobyte dictionary. The dictionary contains over 13000 common words, phrases and other substrings derived from a large corpus of text and HTML documents.[6][7] A pre-defined algorithm can give a compression density boost for short data files.

Replacing deflate with brotli typically gives an increase of 20% in compression density for text files, while compression and decompression speeds are roughly unchanged. Streams compressed with Brotli have the proposed content encoding type "br".

Software and services supporting Brotli

Internet browsers

See also

References

  1. ↑ "Brotli Compressed Data Format". IETF Internet Drafts. 2014-05-16.
  2. ↑ "Brotli Source Code - GitHub". github.com.
  3. ↑ Slater-Robbins, Max (20 Jan 2016). "Chrome and Firefox are about to get a lot faster thanks to Google's new data compression algorithm". techspot.com. Retrieved 20 Jan 2016.
  4. 1 2 Google Open Source Blog: Introducing Brotli: a new compression algorithm for the internet
  5. ↑ "Smaller Fonts with WOFF 2.0 and unicode-range". Google Developers Blog. 18 Feb 2015. Retrieved 20 Jan 2016.
  6. ↑ Richard Chirgwin (23 September 2015). "Google's new squeeze: Brotli compression open-sourced". The Register.
  7. ↑ Alakuijala, Jyrki; Kliuchnikov, Evgenii; Szabadka, Zoltan; Vandevenne, Lode (2015-09-22). "Comparison of Brotli, Deflate, Zopfli, LZMA, LZHAM and Bzip2 Compression Algorithms" (PDF). Google. Retrieved 25 October 2015.
  8. ↑ "Firefox 44 release notes". mozilla.org. Retrieved 2016-01-26.
  9. ↑ "Can I use... Support tables for HTML5, CSS3, etc". caniuse.com. Retrieved 2016-01-07.

External links

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