Lean QR is a lightweight yet fully-featured library for generating QR Codes. It runs in NodeJS and all recent browsers, and includes wrapper components for React, Preact, and native Web Components. Under 4kB compressed.
- ISO 18004 compliant;
- Lightweight (less than 4kB compressed, ~7kB uncompressed, no dependencies);
- still too big? There's also an even smaller "nano" export which has reduced features to fit into ~2kB compressed, ~4kB uncompressed!
- Simple yet flexible API, with sensible defaults for all configuration;
- Supports all standard encodings
out-of-the box:
- including Unicode 😎;
- and Shift-JIS 漢字;
- and supports custom modes for special requirements;
- Automatic encoding to minimise output size;
- Fast enough for lag-free live editing;
- Comprehensive automated testing;
- Multiple output formats (canvas / PNG / SVG / text).
You can see it in action online, or try it from the terminal:
npx lean-qr 'MY MESSAGE HERE'See the Quickstart documentation for NodeJS / Browser / React / Preact / Web Components / CLI usage.
npm install --save lean-qr<canvas id="my-qr-code"></canvas>
<style>
#my-qr-code {
image-rendering: pixelated;
width: 100%;
}
</style>import { generate } from 'lean-qr';
const qrCode = generate('LEAN-QR LIBRARY');
qrCode.toCanvas(document.getElementById('my-qr-code'));There is a bug in JSDOM which prevents this class being available in tests. This issue only affects JSDOM, and can be fixed with:
import { TextEncoder, TextDecoder } from 'node:util';
global.TextEncoder = TextEncoder;
global.TextDecoder = TextDecoder;You can put this in the test file or in Jest's setupFilesAfterEnv config. You
should not put this in your application code.