TypeScript icon, indicating that this package has built-in type declarations

2.3.4 • Public • Published

Lean QR

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 and Preact. Under 4kB compressed.


  • ISO 18004 compliant;
  • Lightweight (less than 4kB compressed, ~7kB uncompressed, no dependencies);
  • 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'

Basic Usage

See the Quickstart documentation for NodeJS / Browser / React / Preact / CLI usage.

npm install --save lean-qr
<canvas id="my-qr-code" />

#my-qr-code {
  image-rendering: pixelated;
  width: 100%;
import { generate } from 'lean-qr';

const qrCode = generate('LEAN-QR LIBRARY');


Jest / JSDOM error: "TextEncoder is not defined"

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.

Full Documentation

Dependencies (0)

    Dev Dependencies (8)

    Package Sidebar


    npm i lean-qr

    Weekly Downloads






    Unpacked Size

    39.3 kB

    Total Files


    Last publish


    • davidje13