QR Code Generator

A QR code (Quick Response code) is a two-dimensional matrix barcode invented by Denso Wave in 1994. It encodes data as a pattern of black and white squares that any camera-enabled device can read instantly. Unlike one-dimensional barcodes, QR codes can store hundreds of characters (URLs, contact cards, Wi-Fi credentials, plain text, and more) in a compact, scannable image.

How QR codes work: Data is encoded using Reed-Solomon error correction, which means a QR code remains readable even when part of it is damaged, dirty, or obscured. The error correction level you choose (L, M, Q, H) controls how much of the code can be lost while still allowing full recovery: L handles 7%, H handles 30%. Higher correction makes the code denser but more resilient.

Size and resolution: The physical size of a QR code doesn't affect what it encodes, but it does affect scan reliability. A 256 px image is ideal for web and digital use. 512 px or 1024 px are better for print materials where you need crisp output at larger sizes.

Color customization: Any high-contrast foreground/background combination works. The scanner measures the contrast between dark modules and the light background, so ensure at least a 4:1 contrast ratio. Avoid light-on-dark QR codes in environments where readers may not support inverted colors.

Where QR codes are used: Product packaging, restaurant menus, business cards, event tickets, Wi-Fi sharing, payment links, marketing campaigns, and app deep links. They bridge physical and digital worlds with a single camera scan, requiring no app on modern smartphones.