How to Create a QR Code

By  on  

QR codes aren't everyone's cup of tea but I quite like them. If I see something I want to remember or check out later, especially when on the road, it's super easy to take a quick picture -- it's much easier than trying to remember a URL and much faster than typing it in on a tiny keyboard.

If you need to generate QR codes, for a client or yourself, there's a really nice JavaScript project: node-qrcode. Let's look at the different wys and output formats you can use to create a QR code!

Start by installing the library:

yarn add qrcode

Create QR Code Image Data

With the QR code utility available, you can generate a data URI for the QR code which you can use with an <img> element:

const generateQR = async text => {
  try {
    console.log(await QRCode.toDataURL(text))
  } catch (err) {
    console.error(err)
  }
}

generateQR("https://davidwalsh.name");

/*
data:image/png;base64,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
*/

Create a QR Code in Terminal

If you want to see the QR code in the terminal via Node.js, you can do so by passing a config object:

const generateQR = async text => {
  try {
    console.log(await QRCode.toString(text, {type: 'terminal'}))
  } catch (err) {
    console.error(err)
  }
}

Create a QR Code Image

You can generate a PNG, SVG, or UTF8 image for the QR code:

const generateQR = async text => {
  try {
    await QRCode.toFile('./davidwash-qr-code.png', text);
  } catch (err) {
    console.error(err)
  }
}

Create a QR Code on Canvas

If you use a utility like Browserify and webpack, you can use qrcode on the client side:

var canvas = document.getElementById('canvas');
const generateQR = async text => {
  try {
    await QRCode.toCanvas(canvas, text)
  } catch (err) {
    console.error(err)
  }
}

generateQR("https://davidwalsh.name");

This awesome QR code library also allows you to create much more than I've shown here, including binary data and with a variety of options. If you need to create a QR code, look no further than node-qr code!

Recent Features

  • By
    Conquering Impostor Syndrome

    Two years ago I documented my struggles with Imposter Syndrome and the response was immense.  I received messages of support and commiseration from new web developers, veteran engineers, and even persons of all experience levels in other professions.  I've even caught myself reading the post...

  • By
    6 Things You Didn&#8217;t Know About Firefox OS

    Firefox OS is all over the tech news and for good reason:  Mozilla's finally given web developers the platform that they need to create apps the way they've been creating them for years -- with CSS, HTML, and JavaScript.  Firefox OS has been rapidly improving...

Incredible Demos

  • By
    Sexy Album Art with MooTools or jQuery

    The way that album information displays is usually insanely boring. Music is supposed to be fun and moving, right? Luckily MooTools and jQuery allow us to communicate that creativity on the web. The XHTML A few structure DIVs and the album information. The CSS The CSS...

  • By
    MooTools-Like Element Creation in jQuery

    I really dislike jQuery's element creation syntax. It's basically the same as typing out HTML but within a JavaScript string...ugly! Luckily Basil Goldman has created a jQuery plugin that allows you to create elements using MooTools-like syntax. Standard jQuery Element Creation Looks exactly like writing out...

Discussion

  1. Daniel Morales Lira

    I thought you were going to show how to do it without libraries :(

  2. Any library for creating QR code in ReactJS ?

  3. root

    is it a link of a QRcode

    generateQR("https://davidwalsh.name");
    

Wrap your code in <pre class="{language}"></pre> tags, link to a GitHub gist, JSFiddle fiddle, or CodePen pen to embed!