Crate qrcodegen[][src]

Expand description

Generates QR Codes from text strings and byte arrays.

This project aims to be the best, clearest QR Code generator library. The primary goals are flexible options and absolute correctness. Secondary goals are compact implementation size and good documentation comments.

Home page with live JavaScript demo, extensive descriptions, and competitor comparisons:


Core features:

  • Available in 6 programming languages, all with nearly equal functionality: Java, TypeScript/JavaScript, Python, Rust, C++, C
  • Significantly shorter code but more documentation comments compared to competing libraries
  • Supports encoding all 40 versions (sizes) and all 4 error correction levels, as per the QR Code Model 2 standard
  • Output format: Raw modules/pixels of the QR symbol
  • Detects finder-like penalty patterns more accurately than other implementations
  • Encodes numeric and special-alphanumeric text in less space than general text
  • Open source code under the permissive MIT License

Manual parameters:

  • User can specify minimum and maximum version numbers allowed, then library will automatically choose smallest version in the range that fits the data
  • User can specify mask pattern manually, otherwise library will automatically evaluate all 8 masks and select the optimal one
  • User can specify absolute error correction level, or allow the library to boost it if it doesn’t increase the version number
  • User can create a list of data segments manually and add ECI segments


extern crate qrcodegen;
use qrcodegen::Mask;
use qrcodegen::QrCode;
use qrcodegen::QrCodeEcc;
use qrcodegen::QrSegment;
use qrcodegen::Version;

Simple operation:

let qr = QrCode::encode_text("Hello, world!",
let svg = to_svg_string(&qr, 4);  // See qrcodegen-demo

Manual operation:

let chrs: Vec<char> = "3141592653589793238462643383".chars().collect();
let segs = QrSegment::make_segments(&chrs);
let qr = QrCode::encode_segments_advanced(&segs, QrCodeEcc::High,
    Version::new(5), Version::new(5), Some(Mask::new(2)), false).unwrap();
for y in 0 .. qr.size() {
    for x in 0 .. qr.size() {
        (... paint qr.get_module(x, y) ...)


An appendable sequence of bits (0s and 1s).

The error type when the supplied data does not fit any QR Code version.

A number between 0 and 7 (inclusive).

A QR Code symbol, which is a type of two-dimension barcode.

A segment of character/binary/control data in a QR Code symbol.

A number between 1 and 40 (inclusive).


The error correction level in a QR Code symbol.

Describes how a segment’s data bits are interpreted.