Zstandard (zstd)
Hacker ApprovedThe most recommended of 14 compression tools
A go-to general-purpose compressor with an excellent size-versus-speed tradeoff and very fast decompression, though Brotli and others can beat it on density for some files.
A go-to general-purpose compressor with an excellent size-versus-speed tradeoff and very fast decompression, though Brotli and others can beat it on density for some files.
125 people gave an opinion
- recommend it
- 111
- criticize it
- 14
- approval share
- 89%
Recommended in 12 of 13 months
- November 2025: recommended
- December 2025: recommended
- January 2026: recommended
- February 2026: recommended
- March 2026: recommended
- April 2026: recommended
- May 2026: recommended
- June 2026: recommended
- July 2026: recommended
- August 2026: recommended
- September 2026: recommended
- October 2026: recommended
- November 2026: not recommended (month in progress)
Why it carries the badge
- 111 people recommend itNeeds 10 or more, met.
- 7.9 recommenders for every criticNeeds 2 to 1 or better, met.
- Recommended in 12 of 13 monthsNeeds 4 or more, met.
The same three rules apply to every product, and the badge can’t be bought. How the badge works
What people say about it
The reasons people give, with the number of comments that give each one. Open a reason to read what they said.
Why people recommend it
Each mark is one comment
Excellent ratio-to-speed tradeoff
“zstd might lose out there, the answer seems to vary based on the tests I look at, but it seems to be better across a very wide range”
Comment from 23 Jan 2026 in “ISO PDF spec is getting Brotli – ~20 % smaller documents with no quality loss” “they're considered to have better tradeoffs in teems of collision compression time and overall space saved by compression”
Comment from 14 Mar 2026 in “An Ode to Bzip” “all that "more" has been ridiculously more optimized in zstd and other modern compression methods”
Comment from 7 Sep 2026 in “bzip3” - Comment from 15 Mar 2026 in “An Ode to Bzip”
- Comment from 22 Sep 2026 in “Can gzip be a language model?”
- Comment from 16 Jul 2026 in “Show HN: misa77 - a codec that decodes 2x faster than LZ4 (at better ratios)”
Very fast decompression
“While it might not compress as small, it decompresses way faster, and might make up for the few extra bytes sent.”
Comment from 20 Mar 2026 in “A static site generator and website transferring under 20kB” “Huge assets took less hard drive space, took less time to download, and took less time to decompress.”
Comment from 2 Sep 2026 in “We could save petabytes of cache storage with Zstandard and Pingora” “competitive with Brotli, which is impressive given how much faster it is to decompress”
Comment from 22 Jan 2026 in “ISO PDF spec is getting Brotli – ~20 % smaller documents with no quality loss” - Comment from 22 Sep 2026 in “Can gzip be a language model?”
- Comment from 22 Jan 2026 in “ISO PDF spec is getting Brotli – ~20 % smaller documents with no quality loss”
Better and faster than gzip
“Zstd, on the other hand, aims to be a “better gzip”, in that it's compresses about as fast as gzip but packs somewhat denser”
Comment from 15 Mar 2026 in “An Ode to Bzip” “For the same CPU utilization if provides twice dense compression compared to regular [-6] gzip”
Comment from 22 Sep 2026 in “Can gzip be a language model?” “If you use Zstandard layers instead of gzip layers, startup time is improved.”
Comment from 14 Feb 2026 in “Understanding the Go Compiler: The Linker” - Comment from 14 Mar 2026 in “An Ode to Bzip”
Tunable levels and options
“instead of tweaking the whole tunnel once, you can use --adapt to dynamically adjust to i/o conditions”
Comment from 31 Aug 2026 in “Transfer files over an Ethernet patch cable” “zstd gives you up to 22 for ultra compression and negative compression levels for ultra fast”
Comment from 7 Sep 2026 in “bzip3” “zstd -19 gave me the best results for small file sizes and fast decompression of text data”
Comment from 15 Apr 2026 in “Comparing Compression Tools” - Comment from 24 Apr 2026 in “Mounting tar archives as a filesystem in WebAssembly”
- Comment from 2 Apr 2026 in “Zstandard Across the Stack”
What people warn about
Each mark is one comment
Not always the densest compression
“no combination of flags to zstd gets it to match the size of brotli's output on that particular file”
Comment from 22 Jan 2026 in “ISO PDF spec is getting Brotli – ~20 % smaller documents with no quality loss” “RePair is faster than compressing with zstd and the size reduction is almost the same”
Comment from 12 Nov 2025 in “Fighting the New York Times' invasion of user privacy” “not in compression density, I don't believe, but yeah, along most other metrics”
Comment from 8 Oct 2026 in “Shipping JPEG XL in Chrome” Not best for every workload
“zstd might lose out there, the answer seems to vary based on the tests I look at, but it seems to be better across a very wide range”
Comment from 23 Jan 2026 in “ISO PDF spec is getting Brotli – ~20 % smaller documents with no quality loss” “Of course for other kinds of files, zstd wins, but all the claims that zstd should be used for ALL applications are extremely wrong.”
Comment from 15 Mar 2026 in “An Ode to Bzip” “It didn't work, or the gains were so marginal that I ended up scrapping the approach.”
Comment from 7 Sep 2026 in “bzip3”
Other compression tools people recommend
The four most recommended other compression tools, with the same counts for each, so you can compare like for like. The tick on each bar marks the 2 to 1 line the badge needs.
See all 14 compression tools, rankedWhat people said
40 of the 153 comments that mention it, newest first. Each links to the original comment.
“my local experiments showed any tricky scheme I could come up beaten by plain large window zstd”
“not in compression density, I don't believe, but yeah, along most other metrics”
“the decompression speed is incredible, so much so that I store everything in zstd”
“For the same CPU utilization if provides twice dense compression compared to regular [-6] gzip”
“the best general purpose compression algorithm, in terms of compression ratio to CPU used”
“Otherwise, if zstd is easy to add, IMO I would always prefer, zstd, lz4 or brotli.”
“zstd gives you up to 22 for ultra compression and negative compression levels for ultra fast”
“It didn't work, or the gains were so marginal that I ended up scrapping the approach.”
“zstd is the go-to compression format these days. It's even supported in low-level software such as many linux filesystems.”
“all that "more" has been ridiculously more optimized in zstd and other modern compression methods”
“If we match the window size of zstd to that of bzip3 we get dramatically different results”
“With a dictionary, small objects - even just a couple of bytes - compress well.”
“Huge assets took less hard drive space, took less time to download, and took less time to decompress.”
“instead of tweaking the whole tunnel once, you can use --adapt to dynamically adjust to i/o conditions”
“zstd, with 1-3 effort (you may even find negative is a overall win), and a trained dictionary”
“if instead you take a raw bitmap and compress it with ZSTD, it typically will be better”
“Zstd already follows the pareto line very closely and also decompresses pretty fast”
“Practical tools, even modern ones like zstd, are mostly based around sliding window compression”
“I found with using various tricks I can get the zstd parquet to be up to 10x (or more) smaller”
“you're better off both in developer ergonomics and speed/space slapping zstd across a flatter binary format”
“I'm used to zstd which by default uses a 128MB window and I usually set it to the max”
“zstd -19 gave me the best results for small file sizes and fast decompression of text data”
“There's also zstd's flush ability that I've used for streaming robotics data.”
“It helps speed it up at high compression levels, though not as much as I'd like.”
“While it might not compress as small, it decompresses way faster, and might make up for the few extra bytes sent.”
“Zstd, on the other hand, aims to be a “better gzip”, in that it's compresses about as fast as gzip but packs somewhat denser”
“Of course for other kinds of files, zstd wins, but all the claims that zstd should be used for ALL applications are extremely wrong.”
“zstd is pretty much Pareto optimal at all settings when looking at size vs. decompression speed”
“they're considered to have better tradeoffs in teems of collision compression time and overall space saved by compression”
“use zstd, which is better and faster, both at compression and decompression”
“If you use Zstandard layers instead of gzip layers, startup time is improved.”
“Having zstd in the stdlib means you can do dictionary-based compression tricks in any Python 3.14 environment”
“Zstandard is a good compressor, but it's not magical; comparing the compressed size of Zstd(A+B) to the common size of Zstd(A) + Zstd(B) is effectively just a complicated way of measuring how many words and phrases the two documents have in common.”
“zstd might lose out there, the answer seems to vary based on the tests I look at, but it seems to be better across a very wide range”
“on a read-many format like pdf zstd's decompression speed is a much better fit”
“competitive with Brotli, which is impressive given how much faster it is to decompress”
“no combination of flags to zstd gets it to match the size of brotli's output on that particular file”
“probably gets you most of the benefit without giving up independence of compression”
“Modern browsers support brotli or zstd, which is a lot better in terms of compression.”
“RePair is faster than compressing with zstd and the size reduction is almost the same”
Counts come from 1,795,640 Hacker News comments, November 2025 to November 2026. How we count. Report a mistake.