madler/zlib
A massively spiffy yet delicately unobtrusive compression library. observed · 2026-08-28
Health v2 · maintenance only
72/100
- Activity 85
- Release rhythm 39
- Longevity 100
Flags: no_license
How is this computed?
round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10) — computed 2026-09-02. Adoption (stars, forks) is never an input.
- gap_med: n/a
- age_days: 5471
- days_rel: 197
- days_push: 93
- n_releases_24m: 1
Adoption not part of the score
7048 stars · 2842 forks observed · 2026-08-28
What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-29, confidence not recorded
zlib is a general-purpose, patent-free data compression library written in C, implementing the zlib, deflate (RFC 1951), and gzip (RFC 1952) formats. It is the de facto standard compression library embedded in countless applications, languages, and file formats such as PNG and PDF.
Use cases
- compress and decompress data in memory with deflate
- read and write gzip files
- decompress Flate streams inside PDF files
- add lossless compression to a C or C++ application
- implement zip file support via minizip
- exchange compressed data between big-endian and little-endian systems
When to choose
- you need a mature, widely portable, patent-free compression library
- you must interoperate with gzip, PNG, PDF, HTTP, or zip formats
- you need a small, fast C library with bindings in nearly every language
When to avoid
- you need the highest compression ratios, where zstd, xz/LZMA, or brotli may outperform it
- you need archive features like encryption or solid compression
- you want a modern API with built-in multithreaded compression
Facets
library · maturity stable
compression file-system developer-tools developer-tools files cross-platform cross-platform c windows cli deflate gzip zlib-format rfc1951 lossless-compression c-library linux macos
3 sources
- readme: https://github.com/madler/zlib · fetched 2026-08-28 · 9cf33e8945e3
- homepage: http://zlib.net/ · fetched 2026-08-29 · 2e77004fe5e8
- site_page: http://zlib.net/zlib_faq.html · fetched 2026-08-29 · d6d9c7a84e82
Member repositories
| Repository | Role | Health v2 |
|---|---|---|
| madler/zlib | main | 72 |
For agents
Data as of 2026-08-30T08:39:29.467469+00:00 · Report a problem