# xz

14 Hacker News commenters recommended xz and 10 criticized it, November 2025 to November 2026. It was recommended in 7 of 13 months.

**Verdict:** Free, widely available compression tool that people find gives good compression ratios and reproducible builds; critics point to a past backdoored release and slow speed.

## Why people recommend it

- Good compression ratio (2 comments): "they're considered to have better tradeoffs in teems of collision compression time and overall space saved by compression" ([source](https://news.ycombinator.com/item?id=47379151)) "got best compression out of xz for SQL" ([source](https://news.ycombinator.com/item?id=47381599))

## What people warn about

- Slow compression and decompression (3 comments): "xz/lzma is quite often too slow or requires too much memory even on decompression" ([source](https://news.ycombinator.com/item?id=48191574)) "bzip2 and xz are extremely slow to compress." ([source](https://news.ycombinator.com/item?id=47379109)) "As expected, xz is super slow." ([source](https://news.ycombinator.com/item?id=46722929))
- Past backdoored release (5 comments): "The upstream xz repository and the xz tarballs have been backdoored." ([source](https://news.ycombinator.com/item?id=48089743)) "it's not that long time ago when we had the xz malware" ([source](https://news.ycombinator.com/item?id=48347001)) "The xz backdoor was a Debian and Red Hat issue" ([source](https://news.ycombinator.com/item?id=48057493))
- Other formats compress better (2 comments): "bzip2 and xz are just no competition for zstd or the gzip family" ([source](https://news.ycombinator.com/item?id=47384413)) "The compression is not superior but already good if you consider just the uncompressed data" ([source](https://news.ycombinator.com/item?id=48191903))

## Alternatives hackers recommend

- [Zstandard (zstd)](https://hackerapproved.com/p/zstd.md): 111 recommend
- [Brotli](https://hackerapproved.com/p/brotli.md): 24 recommend
- [gzip](https://hackerapproved.com/p/gzip.md): 23 recommend
- [tar](https://hackerapproved.com/p/tar.md): 19 recommend
- [NNCP](https://hackerapproved.com/p/nncp.md): 15 recommend

## Cite as

Hacker Approved, "xz", https://hackerapproved.com/p/xz/ (counts from 1,795,640 Hacker News comments, November 2025 to November 2026).