@thermal-label/brother-ql-web

WebUSB browser driver for Brother QL label printers.

Browser Support

| Browser | Support | | ------------- | ------- | | Chrome / Edge | ✅ | | Firefox | ❌ | | Safari | ❌ |

Requires a secure context (https:// or localhost).

Install

pnpm add @thermal-label/brother-ql-web

Quick Start

import { requestPrinter, findMedia } from '@thermal-label/brother-ql-web';

const media = findMedia(259)!; // 62mm continuous
const printer = await requestPrinter();
await printer.printText('Hello WebUSB', media);

Two-Color Printing

Requires a QL-800, QL-810W, or QL-820NWB with DK-22251 labels.

const blackCanvas = document.getElementById('black-layer') as HTMLCanvasElement;
const redCanvas = document.getElementById('red-layer') as HTMLCanvasElement;
const blackCtx = blackCanvas.getContext('2d')!;
const redCtx = redCanvas.getContext('2d')!;

await printer.printTwoColor(
  blackCtx.getImageData(0, 0, blackCanvas.width, blackCanvas.height),
  redCtx.getImageData(0, 0, redCanvas.width, redCanvas.height),
  media,
);

API

requestPrinter(options?)

Opens the browser's USB device picker filtered to all known Brother QL PIDs. Returns a WebBrotherQLPrinter.

fromUSBDevice(device)

Wraps an already-obtained USBDevice. The caller is responsible for opening and claiming the interface.

WebBrotherQLPrinter

| Method | Description | | -------------------------------------------- | ---------------------------------------- | | print(pages, options?) | Send a pre-encoded job | | printText(text, media, options?) | Render and print a text label | | printImage(imageData, media, options?) | Print from ImageData | | printImageURL(url, media, options?) | Fetch URL and print | | printTwoColor(black, red, media, options?) | Two-color label (QL-800 series) | | getStatus() | Query printer status | | isConnected() | Returns true if the USB device is open | | disconnect() | Release interface and close device |

Requirements

• Chromium-based browser (Chrome 61+, Edge 79+)
• Secure context (https:// or localhost)
• User gesture required to call requestPrinter()

License

MIT © Mannes Brak