# lean-qr

> minimal QR code generation

Latest version **2.7.4** (published 2026-09-07) · MIT license · 0 weekly downloads

## Install

```sh
npm install lean-qr
pnpm add lean-qr
yarn add lean-qr
bun add lean-qr
```

Provides the command `lean-qr`.

## Health

**Score 65/100 (B)** — status: active.

Positive: has types; esm support; no vulnerabilities; recently updated; high maintenance score.

Warnings: low downloads.

## Facts

| | |
|---|---|
| Version | 2.7.4 |
| Published | 2026-09-07 |
| First published | 2021-02-02 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | bundled |
| Module format | ESM + CommonJS |
| Dependencies | 0 |
| Unpacked size | 67.2 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 53 |
| Author | David Evans |
| Maintainers | davidje13 |
| Keywords | qr, qr-code, qrcode, barcode, iso-18004, react, react-component, preact, preact-component, vue, vue-component, web-component, console, terminal |

## Links

- npm: https://www.npmjs.com/package/lean-qr
- Repository: https://github.com/davidje13/lean-qr
- Homepage: https://github.com/davidje13/lean-qr#readme
- Issues: https://github.com/davidje13/lean-qr/issues
- npm.io page: https://npm.io/package/lean-qr

## Alternatives

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## Recent versions

- 2.7.4 (latest) — 2026-09-07
- 2.7.3 — 2026-08-13
- 2.7.2 — 2026-06-20
- 2.7.1 — 2026-01-05
- 2.7.0 — 2025-12-30
- 2.6.1 — 2025-12-01
- 2.6.0 — 2025-09-22
- 2.5.0 — 2025-05-20
- 2.4.1 — 2025-03-02
- 2.4.0 — 2025-02-05
- 2.3.5 — 2024-12-14
- 2.3.4 — 2024-03-09
- 2.3.3 — 2024-01-22
- 2.3.2 — 2023-12-23
- 2.3.1 — 2023-06-10
- … 14 more at https://npm.io/package/lean-qr/versions

## README

# <img src="https://qr.davidje13.com/resources/logo.svg" alt="Lean QR" />

Lean QR is a lightweight yet fully-featured library for generating QR Codes. It
runs in Node.js and all recent browsers, and includes wrapper components for
[React, Preact](https://qr.davidje13.com/docs/#extras_react),
[Vue](https://qr.davidje13.com/docs/#extras_vue), and
[native Web Components](https://qr.davidje13.com/docs/#webcomponent). Under 4kB
compressed.

## Features

- ISO 18004 compliant;
- Lightweight (less than 4kB compressed, ~7kB uncompressed, no dependencies);
  - still too big? There's also an
    [even smaller "nano" export](https://qr.davidje13.com/docs/#lean-qr-nano)
    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](https://qr.davidje13.com/docs/#mode)
  out-of-the box:
  - including Unicode 😎;
  - and Shift-JIS 漢字;
  - and supports [custom modes](https://qr.davidje13.com/docs/#custom-modes) for
    special requirements;
- Automatic encoding to minimise output size;
- [Fast enough for lag-free live editing](https://qr.davidje13.com/docs/#comparison);
- Comprehensive automated testing;
- Multiple output formats
  ([canvas](https://qr.davidje13.com/docs/#Bitmap2D_toCanvas) /
  [PNG](https://qr.davidje13.com/docs/#toPngBuffer) /
  [SVG](https://qr.davidje13.com/docs/#toSvgSource) /
  [text](https://qr.davidje13.com/docs/#Bitmap2D_toString)).

You can [see it in action online](https://qr.davidje13.com/), or try it from the
terminal:

```shell
npx lean-qr 'MY MESSAGE HERE'
```

## Basic Usage

See the [Quickstart](https://qr.davidje13.com/docs/#quickstart) documentation
for Node.js / Browser / React / Preact / Vue / Web Components / CLI usage.

```shell
npm install --save lean-qr
```

```html
<canvas id="my-qr-code"></canvas>

<style>
  #my-qr-code {
    image-rendering: pixelated;
    width: 100%;
  }
</style>
```

```javascript
import { generate } from 'lean-qr';

const qrCode = generate('LEAN-QR LIBRARY');
qrCode.toCanvas(document.getElementById('my-qr-code'));
```

## Troubleshooting

### Jest / JSDOM error: "TextEncoder is not defined"

There is a [bug in JSDOM](https://github.com/jsdom/jsdom/issues/2524) which
prevents this class being available in tests. This issue only affects JSDOM, and
can be fixed with:

```js
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

- [Quickstart](https://qr.davidje13.com/docs/#quickstart)
- [API Reference](https://qr.davidje13.com/docs/#api)
- [Source Code](https://github.com/davidje13/lean-qr)
- [Comparison With Other Libraries](https://qr.davidje13.com/docs/#comparison)

---
_Source: https://npm.io/package/lean-qr · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._