# richgel999/miniz: A Single-File zlib Replacement for C and C++ Projects

> miniz is a lossless compression library in one C source and header pair that implements zlib and Deflate, plus optional ZIP archive and PNG writing helpers. It suits embedded, mobile and game code that wants zlib's API without zlib's build and licence setup.

**richgel999/miniz** — miniz: Single C source file zlib-replacement library, originally from code.google.com/p/miniz

- Repository: https://github.com/richgel999/miniz
- Stars: 2,882 · Forks: 424
- Language: C++
- License: MIT
- Published: 2026-09-28 · Updated: 2026-09-28 · Language: en
- Canonical page: https://hysenlabs.com/projects/richgel999-miniz

## The problem miniz solves: zlib's API without zlib's terms

miniz is a lossless compression library in a single source file that implements the zlib (RFC 1950) and Deflate (RFC 1951) specifications. The readme says it supports the most commonly used functions exported by the zlib library while being a completely independent implementation, so zlib's licensing requirements do not apply. That is the core pitch: you get the API shape you already know, under MIT, in a file pair you can drop into a project.

The audience is narrow and specific. The readme points at embedded, mobile and game development as the situations the ZIP archive APIs were written for. The low-level compressor (tdefl) and decompressor (tinfl) have state structs that can be saved and restored with memcpy, and the readme states the low-level codec APIs do not use the heap at all. If you are writing code that cannot call malloc during decompression, that sentence is the reason to read further.

## How the amalgamated file pair and the tdefl/tinfl split work

The repository ships both a flat pair and the pieces it is assembled from. Top-level entries include miniz.c and miniz.h alongside miniz_common.h, miniz_tdef.c, miniz_tdef.h, miniz_tinfl.c, miniz_tinfl.h, miniz_zip.c and miniz_zip.h. The readme explains the relationship: releases are published as a pair of miniz.c and miniz.h files which can be added to a project, and that pair is produced by amalgamating the separate source and header files during build. The amalgamate.sh script in the repository root is the tool that does this.

The codec split matters more than the packaging. The inflater, including optional zlib header parsing and Adler-32 checking, is implemented as a single function written as a coroutine, and the readme notes it is separately available in a roughly 550 line file, miniz_tinfl.c. The compressor is not block based; the readme states miniz fully supports stream based processing through the same coroutine-style approach, and that the zlib-style API functions can be called a single byte at a time. That is a different data flow from block-oriented compressors, which need a full block before they emit anything.

## Adding miniz through vcpkg and compressing a buffer on first run

The readme gives one package-manager route. The vcpkg port is maintained by Microsoft team members and community contributors, and the readme says to create an issue or pull request on the vcpkg repository if the version is out of date.

```bash
git clone https://github.com/Microsoft/vcpkg.git
cd vcpkg
./bootstrap-vcpkg.sh
./vcpkg integrate install
./vcpkg install miniz
```

After that, linking against the installed miniz target gives you the zlib-compatible functions. The readme also says you can use miniz as a CMake or Meson module, or with a build system of your choice, and the repository carries CMakeLists.txt, meson.build and Config.cmake.in for those paths. If you prefer no build integration at all, download the miniz.c and miniz.h pair from the releases page and add both files to your project directly.

For a first real use, the repository includes six example files under examples/, named example1.c through example6.c, which the readme says demonstrate how to use the module's major features. Start with those rather than guessing at the API: the readme states the assumption is that the user is already familiar with the basic zlib API, and points at the examples as the practical entry point. A typical first task is compressing a memory buffer with the zlib-style calls, then decompressing it back, which exercises the same code path that libpng and libzip use when miniz stands in for zlib.

## Where miniz is the wrong tool

Encrypted archives are not supported. The readme lists this under Known Problems in plain terms, so any workflow that expects password-protected ZIP files has to look elsewhere or handle encryption above miniz's layer.

The second limitation is documentation. The readme itself calls it minimal and says an API wiki still needs to be written; the current approach is comments before each enum and API plus the six examples. If your team relies on reference documentation rather than reading headers, budget time for that. There is also a performance boundary the readme is honest about: at level 1, miniz compresses around 5 to 9 percent better than minilzo but is approximately 35 percent slower. If raw speed at the lowest level is the only metric that matters, a dedicated fast compressor wins. And if you need a specific zlib behaviour that is not among the functions miniz reimplements, the readme does not claim complete API parity, only the most commonly used functions.

## miniz vs zlib and miniz vs minizip

Against zlib, the difference is implementation and licence, not format. Both produce zlib and Deflate streams, and the readme says miniz is a drop-in replacement for zlib's most used APIs, tested in projects such as libpng and libzip. What changes is that miniz is a completely independent implementation, so zlib's licensing requirements do not apply, and that it arrives as one source and header pair rather than a library you build and link. The readme also notes miniz's compression speed has been tuned to be comparable to zlib's, with levels 2 through 9 designed to compare favourably against zlib's ratio and speed.

Against minizip, the difference is scope. minizip is the ZIP-side utility that ships alongside zlib, while miniz bundles a fairly complete but totally optional set of ZIP archive manipulation and extraction APIs inside the same library that does the compression. The readme describes those archive APIs as purposely just powerful enough to write an entire archiver given some additional higher-level logic. So the choice is less about format support and more about whether you want archive handling in the same file pair as your Deflate codec.

## Release cadence, amalgamation cost and the MIT licence

The repository is not archived, and the last push was on 2026-07-01. Recent releases are 3.1.0 on 2025-09-21, 3.1.1 on 2026-02-03 and 3.1.2 on 2026-07-01. That is roughly two releases a year across the visible window, which matters for planning: you are not tracking a fast-moving target, but you also should not expect frequent fixes.

The upgrade cost depends on how you consume it. If you vendor the amalgamated pair, upgrading means replacing two files and re-running your own build, and the readme points to the releases page as the source for that pair. If you use vcpkg, upgrades arrive through the port, and the readme explicitly asks for issues or pull requests on the vcpkg repository when the port lags. If you build from the split sources with CMake or Meson, the amalgamation step in amalgamate.sh is part of your build, so a source change can affect the generated pair.

On licensing, miniz is MIT. The readme frames the project as an independent implementation so that zlib's licensing requirements do not apply, which is the practical reason many teams pick it. That is a statement about the project's own licence, not legal advice about your product; if your organisation has strict dependency review, route the MIT text and the patent section of the readme through whoever handles that. The readme's patent note says miniz purposely uses the same core algorithms as zlib, with vanilla hash chaining as described in RFC 1951, and argues that if miniz were exposed to a patent attack then zlib and gzip would likely be at serious risk too. Treat that as the author's stated position rather than a guarantee.

## Conclusion

Adopt miniz when you want zlib's most used API inside one vendored miniz.c/miniz.h pair, or when you need the heap-free tdefl/tinfl codecs and a stream-based inflater in about 550 lines. Do not adopt it if you need encrypted ZIP archives, because the readme lists that as unsupported, or if you expect an API wiki, because the readme states the documentation is minimal. Before committing, verify the level 1 trade-off yourself: the readme claims 5 to 9 percent better compression than minilzo at roughly 35 percent slower speed, and that ratio is the number your build has to live with.

## FAQ

### What is miniz?

miniz is a lossless, high performance data compression library in a single source file that implements the zlib (RFC 1950) and Deflate (RFC 1951) specifications. It also includes optional functions for writing PNG files and for reading, writing and appending ZIP archives, and it is MIT licensed.

### How do I use miniz?

Add the released miniz.c and miniz.h pair to your project, or use it as a CMake or Meson module. The readme assumes familiarity with the basic zlib API and points to six examples in the examples directory that demonstrate the major features.

### How does miniz compare with zlib?

miniz supports the most commonly used functions exported by zlib but is a completely independent implementation, so zlib's licensing requirements do not apply. The readme says its compression speed has been tuned to be comparable to zlib's, and that at levels 2 through 9 it is designed to compare favourably against zlib's ratio and speed.

### How does miniz compare with minizip?

miniz bundles a fairly complete but optional set of ZIP archive manipulation and extraction APIs alongside its Deflate codec, while minizip is the ZIP-side utility associated with zlib. The readme describes miniz's archive APIs as purposely just powerful enough to write an entire archiver with some additional higher-level logic.

## Sources

- [Issues](https://github.com/richgel999/miniz/issues)
- [License: MIT](https://github.com/richgel999/miniz/blob/master/LICENSE)
- [README](https://github.com/richgel999/miniz/blob/master/README.md)
- [Releases](https://github.com/richgel999/miniz/releases)
- [richgel999/miniz on GitHub](https://github.com/richgel999/miniz)

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Hysen Labs editorial analysis, written from the project's own repository and release notes. Cite the canonical page: https://hysenlabs.com/projects/richgel999-miniz