Print QR code in thermal printer by using a free plugin to send ESC POS commands

How to print QR codes on Thermal printer

Summary: In this post I will show you how to print readable QR codes on a thermal printer (also called ticket printer, pos printer, etc.) using JavaScript and a plugin.

If you have followed my posts, you will know that a long time ago I developed a plugin and I have added new features, until today we print QR codes on a thermal printer.

Some time ago I showed you how to print a ticket /receipt directly from browser, today we will use it to print a QR code.

Print QR codes on a thermal printer

The process is simple, but I recommend to try the hello world example first:

Print ticket in thermal printer directly from browser

Download the plugin and run it, remember to give it permissions if required. It will be executed in the background.

Then install your printer and make sure it is shared.

Now open an HTML document, include the script and then in another script create a ConectorPluginV3 object like this:

const imprimirQr = async (nombreImpresora) => {
    const contenido = "Soy el contenido de un QR. Visita parzibyte.me";
    if (!contenido) {
        return alert("Escribe el contenido del QR");
    }
    const conector = new ConectorPluginV3(URLPlugin);
    conector.Iniciar();
    conector.EscribirTexto("Veamos un QR:");
    conector.Feed(1);
    conector.ImprimirCodigoQr(contenido, 160, 2, ConectorPluginV3.TAMAÑO_IMAGEN_NORMAL);
    conector.Iniciar(); //Nota: esto solo es necesario en ocasiones, por ejemplo en mi impresora debo hacerlo siempre que acabo de imprimir una imagen
    conector.Feed(1);
    const respuesta = await conector
        .imprimirEn(nombreImpresora);
    if (respuesta === true) {
        alert("Impreso correctamente");
    } else {
        alert("Error: " + respuesta);
    }
}

You can call the ImprimirCodigoQr method after or before anything, and align it like everything else, just make sure you call it after a Feed.

Remember to put the name of your printer when calling imprimirEn. When testing it in my case it is like this:

Print QR code in thermal printer by using a free plugin to send ESC POS commands
Print QR code in thermal printer by using a free plugin to send ESC POS commands

Try it yourself

If you want to generate and print QR codes by yourself without writing any line of code, navigate to this example (remember that the plugin must be running and the printer must be shared).

You can see its code here.


I am available for hiring if you need help! I can help you with your project or homework feel free to contact me.
If you liked the post, show your appreciation by sharing it, or making a donation

3 thoughts on “How to print QR codes on Thermal printer”

  1. This looks like it will do exactly what I am looking to accomplish … however the example page recognizes my thermal printer (Seiko Smart Label 650) but errors out when attempting to print.

    So – I downloaded the plug-in and tried from my own pages and the printer wakes but errors before actually printing anything.

    Is the printer incompatible?- Thoughts?

    I am interested in the pro version of plug in if can get to work
    thx

    1. Hi this is from the on-screen example log
      6/14/2020, 11:50:22 PM Cargando lista…
      6/14/2020, 11:50:24 PM Lista cargada
      6/14/2020, 11:50:27 PM Imprimiendo…
      6/14/2020, 11:50:27 PM Al imprimir el código QR tenemos: Impreso correctamente

      I can email you the GET and POST from the console of helpful
      The printer wakes and the print head resets but no printing. (the printer does work for other labels)

Leave a Comment

Your email address will not be published. Required fields are marked *