What is a QR code?
A QR code (Quick Response code) is a two-dimensional barcode that can store URLs, plain text, contact information, Wi-Fi credentials, and much more. Unlike traditional barcodes that only hold a few dozen characters, a QR code can hold up to 4,296 alphanumeric characters. They are designed to be scanned quickly by smartphone cameras and dedicated readers.
How do QR codes work?
QR codes encode data as a matrix of black and white squares. The pattern includes finder patterns in three corners (so the scanner knows the orientation), alignment patterns for distortion correction, and the actual encoded data. Error-correction built into the format means a QR code can still be read even if up to 30% of it is obscured or damaged.
Common uses for QR codes
QR codes are widely used on restaurant menus, product packaging, business cards, event tickets, payment systems (like Apple Pay and Google Pay), and marketing materials. Developers use them to share URLs, app download links, and API endpoints quickly. They are also useful for sharing Wi-Fi passwords without typing them out.
Tips for better QR codes
Use a larger size (300×300 or bigger) for print materials where the code will be viewed from a distance. Keep your target URL short — long URLs produce denser, harder-to-scan QR codes. Always test your generated QR code with at least two different phone cameras before publishing. Add sufficient white space (quiet zone) around the code when embedding it in designs.