Question about NTFS Compression

Question

Hi,

According to the documentation for the algorithms used in NTFS compression, there are multiple algorithms which are used. Specifically, there is LZ77+Huffman, Plain LZ77, and LZNT1, according to the most recent version of the documentation.

I'm wondering, in Windows 10, which of these algorithms get used when? How does Windows 10 decide which of these algorithms to use for a given file to be compressed? Thank you,

James Pedersen

Answer 1

Hello James Pedersen, The file compression algorithm used by the NTFS file system is Lempel-Ziv compression. This is a lossless compression algorithm, which means that no data is lost when compressing and decompressing the file, as opposed to lossy compression algorithms such as JPEG, where some data is lost each time data compression and decompression occur. Reference File Compression and Decompression for more informant: https://learn.microsoft.com/en-us/windows/win32/fileio/file-compression-and-decompression