Connecting a thermal printer by Bluetooth
Published , updated
A receipt has to print in one action. The cashier presses a button and paper comes out. Anything that adds a confirmation step, a preview or a choice of printer is wrong for a counter, no matter how normal it looks on a desktop.
That is why the till does not use the browser print dialog. It builds the receipt as ESC/POS instructions, the language thermal printers actually speak, and sends those bytes to the paired printer directly.
What ESC/POS means here
ESC/POS is a set of instructions thermal printers have understood for decades. Rather than a page description, it is a stream of small commands: print this text, make it bold, feed the paper, cut.
The useful consequence is that the printer needs no driver and no font package. It receives instructions it already knows. It is also why Urdu goes across as an image rather than text, since the instruction set has no Urdu characters to reference.
Bluetooth or USB-C
Both work, and the choice is physical rather than technical.
- Bluetooth suits a counter where the tablet moves, or where running a cable is awkward. The pairing is done once during setup.
- USB-C suits a fixed station. Nothing to re-pair, nothing to lose to interference, and the printer can usually draw power from the same arrangement.
Shops with a tablet that leaves the counter tend to prefer Bluetooth. Shops with a till that never moves tend to prefer the cable.
When printing stops working
In rough order of how often each is actually the cause:
- Paper. An empty roll produces exactly the same silence as a software fault.
- The pairing dropped. Check the printer is still paired in the tablet’s own Bluetooth settings, not in the till. A printer that was switched off and on sometimes comes back unpaired.
- The printer is asleep or out of charge. Battery models power down.
- Another device grabbed it. Bluetooth printers generally accept one connection at a time, so a second tablet that paired with it earlier can hold it.
Only after those four is it worth looking at the till itself. The pattern that points at software rather than hardware is a printer that pairs, stays paired, and prints a test page from the operating system but nothing from the till.
Setup is done for you
Pairing the printer and printing a real test ticket is part of installation, done on site rather than left as a first task. That is deliberate: the step where someone gives up on a new system is usually the one where the hardware will not talk to the software on day one.
Questions
Can a browser print to a thermal printer directly?
A browser can send bytes straight to a paired thermal printer rather than going through the operating system print dialog. The till builds the receipt as printer instructions and hands them over, so no driver or print preview is involved.
Why not just use the normal print dialog for receipts?
The print dialog is built for pages of paper, so it adds margins, scaling and a confirmation step to something that has to happen in under a second. Sending printer instructions directly keeps a receipt to one action at the counter.
What should be checked first when a thermal printer will not print?
Check that the printer is paired with the tablet at the operating system level and that it has paper, before looking at the till at all. Most printing failures at a counter are a dropped pairing or an empty roll rather than software.
Ask about your own shop
Every shop is set up by hand, so the first step is a conversation. If this will not fit what you do, we will tell you.