How to connect USB in Chrome & find device numbers (VID / PID)
Open this page in Google Chrome, Microsoft Edge, or Opera (Safari and Firefox do not support WebUSB).
Connect the Xprinter XP-420B via USB and power it on. WebUSB works on localhost or over https://.
Click Connect printer and select your printer from the browser pairing popup.
Choose paper size, enter label details or import CSV, then click Print.
How to find your printer's number (Vendor ID & Product ID)
If your printer does not appear in the connection dialog, it may use a different USB Vendor ID (VID) or Product ID (PID). You can check its numbers using:
In Google Chrome: Open a new browser tab and navigate to chrome://usb-internals or chrome://device-log. Unplug and replug the USB cable to identify the printer and view its hex VID and PID numbers.
On macOS: Go to > About This Mac > System Report > Hardware > USB. Click the printer to view its Vendor ID (e.g. 0x0483, 0x6868, 0x0416) and Product ID (e.g. 0x5720, 0x0200).
On Windows: Open Device Manager > Universal Serial Bus devices (or Printers) > right-click your printer > Properties > Details > Hardware Ids to see VID_xxxx&PID_yyyy.
On Linux: Run lsusb in the terminal to inspect all connected USB devices and their ID xxxx:yyyy identifiers.