Why can’t browsers print directly to USB receipt printers?
Because browsers are built to prevent exactly that. A web page that could send raw data to any USB device would be a security catastrophe — so the browser sandbox forbids it, deliberately and permanently. This is the central plumbing problem of every browser-based POS system: the software runs in a tab, the receipt printer hangs off a USB port, and the platform standing between them is designed to keep web pages away from hardware. Every solution to web receipt printing is a way around this wall — and the differences between the workarounds matter.
Why the obvious answers fail
- window.print() — the browser’s print dialog treats the page as a document: it paginates for A4/Letter, invites the user to click through a dialog on every sale, and mangles ESC/POS entirely (raw commands are not a document). Receipts need silent, instant, raw printing; the print dialog offers none of the three.
- Silent-print browser flags (kiosk mode) — remove the dialog but still route through the document-printing pipeline, still driver-dependent, still incapable of raw ESC/POS features like cutting and cash-drawer pulses. Fragile in exactly the ways checkout lanes cannot afford.
- WebUSB — the real API has real limits: it is Chromium-only, requires a permission prompt per device, and — decisively — standard printer device classes are blocked from WebUSB claiming on most platforms, because the OS holds the printer interface. It solves adjacent problems; it does not solve receipt printing.
- Cloud printing services — relay the job over the internet to come back to a printer three feet away: added latency on every receipt, a hard dependency on connectivity at the worst possible moment (a busy checkout during an outage), and business data transiting third-party infrastructure. See our security comparison for the full picture.
The answer that works: a local bridge
The pattern the industry converged on is a small native application on the same machine as the printer: it has real OS-level USB access (which native apps are allowed to have), and it exposes a local HTTPS API on localhost. The browser POS sends the receipt to https://localhost — ordinary web traffic, fully sandbox-legal — and the bridge writes raw ESC/POS bytes to the printer. Silent, instant, no dialog, full command support including cuts and drawer pulses, and no internet round-trip: the print job never leaves the machine.
This is exactly what AnyPrint is: DAXTOP’s free Windows bridge that pairs once with your browser-based POS and prints raw ESC/POS to any compatible USB thermal printer from then on. It exists because DAXTOP’s own POS platform (daxtop.com) is browser-based and needed the wall solved properly — and the same bridge works for any web POS through its documented local API.