Apple Open Source Its LZFSE Compression Library

LZFSE Compression Algorithm
LZFSE Compression Algorithm

According to a recent report, Apple has open sourced its news lossless compression algorithm, LZFSE, which was introduced last year along with iOS 9 and OS X 10.10.

LZFSE offers the same compression gain as Zlib Level 5 while being 2-3x faster and with higher energy efficiency. The decompression speed is also greater than Zlib.

To achieve this, it uses Lempel-Ziv style data-compression algorithm using Finite State Entropy coding. Jarek Duda’s work on Asymmetric Numeral Systems (ANS) for entropy coding serves as the basis for Finite State Entropy. ANS aims to “end the trade-off between speed and rate” and used for both precise coding and very fast encoding, with support for data encryption. LZFSE is one of a growing number of compression libraries that use ANS in place of the more traditional Huffman and arithmetic coding.

However, LZFSE is neither the best nor the fastest algorithm out there. In fact, Apple states that LZ4 is faster than LZFSE while LZMA provides a higher compression ratio. Also, Apple prefers LZFSE when compression and speed are more or less equally important and you want reduce energy consumption.

Apple has made the code to LZFSE compression library and CLI utility open-source via GitHub.


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  • achal

    what do you mean by energy consumption while compressing??????????????????????