# ZXing vs quirc vs zbar

> ZXing is the reference family: the Java original is in maintenance mode but zxing-cpp is actively developed with bindings for Python, WebAssembly and mobile. zbar is a fast C decoder kept alive by a community fork. quirc is a few thousand lines of dependency-free C for embedded targets. For new projects, zxing-cpp is the safe default.

Source: https://useqr.app/docs/developers/zxing-vs-quirc-vs-zbar · Last reviewed 2026-08-21 · UseQR is free forever, no signup.

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## Three engines, three philosophies

Almost every QR scanner you have ever used sits on one of three open-source decoding
engines. They embody different trade-offs:

| | ZXing family | zbar | quirc |
|---|---|---|---|
| Origin | Java, Google 20% project | C, originally for Linux webcams | C, written for embedded use |
| Licence | Apache-2.0 | LGPL-2.1 | ISC |
| Active development | zxing-cpp: yes; Java: maintenance mode | community fork | low-volume but alive |
| Codebase size | large | medium | a few thousand lines, zero dependencies |
| Symbologies | many 1D + 2D | many 1D + 2D | QR only |
| Bindings | Python, WASM, iOS, Android, .NET | Python (pyzbar), Perl, more | C API; ports exist |

## ZXing: the reference that got rewritten

ZXing ("zebra crossing") is the historic reference decoder, for years, "does it decode
in ZXing" was the practical definition of a valid QR code. The Java project announced
maintenance mode, but the story did not end there: **zxing-cpp**, a from-scratch C++
port, became the actively developed centre of gravity, with official Python bindings
(`pip install zxing-cpp`), a WebAssembly build (zxing-wasm) and mobile wrappers.

Its decoding is the most thorough of the three: it handles
[mirrored codes](/docs/spec/mirrored-qr-codes), inverted polarity, damaged finder
patterns and a `tryHarder` mode that trades latency for recovery. That thoroughness is
why UseQR standardised on zxing-wasm everywhere a decode happens: the browser
[scanner](/scan), `POST /api/v1/decode`, the verify endpoint and the CI suite all run
the same engine, so "scannable" means the same thing in every context.

## zbar: fast, old, forked

zbar is a C library from the webcam era, and its architecture (a streaming scanner
that processes video lines) makes it very fast on modest hardware. It powers the
`zbarimg` CLI and Python's pyzbar, and it remains a perfectly good decoder for clean,
well-lit images. The honesty: the original project stalled over a decade ago, and
maintenance lives in a community fork. Its LGPL licence also needs a moment's thought
in statically linked or app-store contexts, where Apache/ISC engines are simpler.

## quirc: the embedded specialist

quirc does one thing: decode QR codes, in portable C, in a few thousand lines, with no
dependencies and modest, predictable memory use. That makes it the default choice on
microcontrollers and camera firmware where zxing-cpp will not fit. It supports QR only,
no 1D barcodes, no [Micro QR](/glossary/micro-qr), and its tolerance of blur,
damage and perspective is the narrowest of the three. On an ESP32 reading codes off a
conveyor at fixed distance, that is fine; in a general-purpose phone scanner it is not.

## On benchmarks

Published decoder benchmarks age badly and depend enormously on the test corpus:
resolution, blur, damage, lighting, angle. Rather than quote numbers we cannot stand
behind: the ranking that holds across most corpora is that zxing-cpp recovers the most
marginal codes, zbar is competitive on clean images and cheap on CPU, and quirc trades
robustness for size. If decode margin matters to you, measure it on *your* images:
the [decode-verify loop](/docs/developers/building-a-decode-verify-loop) is exactly
that measurement, run continuously.

## Recommendations

- **New project, any platform:** zxing-cpp (or zxing-wasm in JS). Active, permissive,
  thorough.
- **Legacy pipeline already on zbar:** no urgent reason to move; it still decodes.
- **Embedded, kilobytes matter:** quirc, and control your imaging conditions.
- **No local install possible:** the keyless
  [decode API](/docs/developers/decode-a-qr-code-programmatically) runs zxing for you.

## FAQ

### Is ZXing dead?
The original Java project is in maintenance mode, not deleted, but new development happens in zxing-cpp, a C++ rewrite with Python, WebAssembly, iOS and Android bindings that is actively maintained. New projects should target zxing-cpp.

### Which QR decoder is the most accurate?
Across most image sets, zxing-cpp recovers the most damaged and marginal codes, especially with tryHarder enabled. Exact rates depend heavily on your images, so test with your own corpus rather than trusting published benchmarks.

### What is quirc used for?
Embedded systems. quirc is a few thousand lines of dependency-free ISC-licensed C with modest memory needs, which makes it the standard choice for microcontrollers and firmware where larger engines will not fit. It decodes QR codes only.

### Does zbar still work?
Yes. The original project stalled long ago but a community fork maintains it, and tools built on it (zbarimg, pyzbar), still decode reliably. Its LGPL licence deserves a check in statically linked commercial builds.

## Try it

- https://useqr.app/scan
- https://useqr.app/validate
- https://useqr.app/url