What Is a QR Code? How QR Codes Work and How to Make One for Free

QR codes — those square black-and-white patterns — are everywhere. Restaurants, concert tickets, payment apps, business cards, even gravestones. But what exactly is a QR code, and how do you create one?

What Is a QR Code? QR stands for 'Quick Response.' It's a type of 2D barcode invented in 1994 by Denso Wave (a Toyota subsidiary) to track vehicle parts during manufacturing. Unlike traditional barcodes that store data in one direction, QR codes store data in both horizontal and vertical dimensions — which is why they hold much more information.

How QR Codes Work: A QR code contains data encoded in a grid of black and white squares. The three large corner squares are 'finder patterns' that help scanners orient the code. The remaining squares encode the actual data — which can be a URL, text, contact info, Wi-Fi credentials, or even cryptocurrency addresses.

Error Correction: One clever feature of QR codes is built-in error correction. Even if up to 30% of the code is damaged or obscured, it can still be read. This is why you can add logos to QR codes and they still work.

Common Uses Today: Contactless payments (PromptPay in Thailand, Venmo in the US). Restaurant menus and ordering. Business card sharing. Wi-Fi password sharing. Event tickets and boarding passes. Product packaging and marketing.

Create Your Own: Zelve Tool AI's free QR Code Generator lets you create QR codes from any text or URL. Choose your error correction level, size, and download as a PNG. No signup required.