Check out the demo on GitHub Pages!
This little tool is a work-in-progress that will eventually allow you to print images on a Brother QL-series label printer directly from the browser, no drivers or installation needed! Just plug your printer's USB cable into your computer, select an image, and click the "Print Label" button to get started.
The page uses the WebUSB API to communicate directly to your Brother label printer over USB. It manually converts the selected image to monochrome and generates the necessary raster data to print it on the label printer. The printer commands are sent as a series of bytes to the printer using the WebUSB API.
This is a work-in-progress protoype and is hardcoded to work with a Brother QL-700 printer and a 62mm x 29mm die-cut label roll. Most of the guts are ready to be expanded to other printers, labels, and features, but I've not gotten there yet.
This work is heavily inspired by the brother_ql Python library by Philipp Klaus that uses PyUSB to send commands to Brother QL-series label printers.