https://github.com/davidje13/lean-qr
Minimal library for generating QR codes in the browser and server-side.
https://github.com/davidje13/lean-qr
Last synced: 10 months ago
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Minimal library for generating QR codes in the browser and server-side.
- Host: GitHub
- URL: https://github.com/davidje13/lean-qr
- Owner: davidje13
- License: mit
- Created: 2021-01-31T01:15:31.000Z (over 5 years ago)
- Default Branch: main
- Last Pushed: 2025-08-16T22:26:28.000Z (11 months ago)
- Last Synced: 2025-08-17T00:16:48.415Z (11 months ago)
- Language: JavaScript
- Homepage: https://qr.davidje13.com/
- Size: 777 KB
- Stars: 37
- Watchers: 2
- Forks: 2
- Open Issues: 3
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# 
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), 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 æ¼¢å—;
- 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 / Web Components / CLI usage.
```shell
npm install --save lean-qr
```
```html
#my-qr-code {
image-rendering: pixelated;
width: 100%;
}
```
```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)
- [Migrating from Version 1.x to 2.x](https://qr.davidje13.com/docs/#v2)
- [Source Code](https://github.com/davidje13/lean-qr)
- [Comparison With Other Libraries](https://qr.davidje13.com/docs/#comparison)