How to Generate QR Codes

March 22, 2026 · 6 min read

QR codes are those square barcodes you see everywhere — restaurant menus, event tickets, product packaging, and marketing materials. They encode data (usually a URL) that any smartphone camera can scan instantly. Whether you need to generate one for a project, a business card, or a WiFi login, this guide covers every approach.

What Is a QR Code?

QR stands for "Quick Response." Invented in 1994 by Denso Wave for tracking automotive parts, QR codes can encode up to 4,296 alphanumeric characters. They use Reed-Solomon error correction, meaning they still work even if part of the code is damaged or obscured.

QR codes can encode several types of data:

URLs — the most common use case (e.g., https://utilshed.com)
Plain text — any string up to ~4KB
WiFi credentials — format: WIFI:T:WPA;S:NetworkName;P:Password;;
vCards — contact information
Email addresses — mailto:user@example.com
Phone numbers — tel:+15551234567

Method 1: Use a Free Online Generator

The fastest way to create a QR code is with an online tool. No signup, no install — just paste your data and download the image.

Generate a QR Code Instantly

Enter any URL or text to generate a downloadable QR code.

Open QR Code Generator

Method 2: Generate QR Codes in JavaScript

The qrcode npm package is the most popular choice for Node.js and browser-based QR code generation.

Install

npm install qrcode

Generate in Node.js (save to file)

const QRCode = require('qrcode');

// Generate and save as PNG
await QRCode.toFile('qr.png', 'https://utilshed.com', {
  width: 300,
  margin: 2,
  color: { dark: '#000000', light: '#ffffff' }
});

// Generate as data URL (for embedding in HTML)
const dataUrl = await QRCode.toDataURL('https://utilshed.com');
console.log(dataUrl); // data:image/png;base64,...

Generate in the browser

<canvas id="qr"></canvas>
<script src="https://cdn.jsdelivr.net/npm/qrcode/build/qrcode.min.js"></script>
<script>
  QRCode.toCanvas(document.getElementById('qr'), 'https://utilshed.com');
</script>

Method 3: Generate QR Codes in Python

pip install qrcode[pil]

import qrcode

# Simple generation
img = qrcode.make('https://utilshed.com')
img.save('qr.png')

# With customization
qr = qrcode.QRCode(
    version=1,
    error_correction=qrcode.constants.ERROR_CORRECT_H,
    box_size=10,
    border=4,
)
qr.add_data('https://utilshed.com')
qr.make(fit=True)
img = qr.make_image(fill_color='black', back_color='white')
img.save('qr_custom.png')

The error_correction parameter controls how much of the QR code can be damaged and still scan:

ERROR_CORRECT_L — 7% recovery
ERROR_CORRECT_M — 15% (default)
ERROR_CORRECT_Q — 25%
ERROR_CORRECT_H — 30% (use this if you want to add a logo overlay)

Method 4: Command Line

Generate QR codes directly from the terminal:

# Using qrencode (Linux/macOS)
sudo apt install qrencode   # Debian/Ubuntu
brew install qrencode        # macOS

qrencode -o qr.png 'https://utilshed.com'
qrencode -t UTF8 'https://utilshed.com'  # Print to terminal

Method 5: Using a QR Code API

If you need to generate QR codes dynamically without installing anything, use a public API:

# Google Charts API (simple, no auth needed)
https://chart.googleapis.com/chart?chs=300x300&cht=qr&chl=https://utilshed.com

# Or use curl to download
curl -o qr.png "https://chart.googleapis.com/chart?chs=300x300&cht=qr&chl=https://utilshed.com"

WiFi QR Codes

One of the most practical QR code use cases — let guests connect to your WiFi by scanning a code instead of typing the password:

# WiFi QR code format
WIFI:T:WPA;S:MyNetworkName;P:MyPassword;;

# For open networks (no password)
WIFI:T:nopass;S:MyNetworkName;;

# For WEP (legacy)
WIFI:T:WEP;S:MyNetworkName;P:MyPassword;;

Paste the WiFi string into any QR code generator and share the resulting image. Most modern phones will auto-detect the WiFi format and offer to connect.

Best Practices

Size matters — QR codes should be at least 2cm x 2cm for reliable scanning. For billboards or signs, use at least 10cm.
Contrast is key — Use dark foreground on light background. Avoid low-contrast color combinations.
Use URL shorteners for long URLs — Shorter data = simpler QR code = easier to scan.
Test before printing — Always scan your QR code with multiple phones before using it in print.
Use high error correction for print — ERROR_CORRECT_H (30%) is recommended for physical media that might get scratched or folded.
Add a quiet zone — Leave white space around the QR code (most libraries add this by default with the margin option).

Try It Now

Need a QR code right now? Use the free QR Code Generator on UtilShed — paste any URL or text, customize the size, and download instantly.

Related tools you might find useful:

URL Encoder — encode URLs before embedding them in QR codes
Base64 Encoder — encode binary data as text for QR payloads
Password Generator — generate a strong WiFi password, then create a QR code for it