QR Code Generator
Generate QR codes for URLs, Wi-Fi, contacts, and plain text.
What is a QR code?
A QR code (Quick Response code) is a type of two-dimensional barcode that stores information in a grid of black and white squares. Originally developed by Denso Wave in 1994 for tracking automotive parts, QR codes became ubiquitous in the smartphone era because they can be scanned instantly by any device with a camera — no separate barcode scanner required.
QR codes can encode text, URLs, Wi-Fi credentials, contact cards (vCard), email addresses, phone numbers, calendar events, and more. The amount of data that can be encoded depends on the QR code version (size) and error correction level: the maximum is around 3,000 alphanumeric characters. Higher error correction levels allow the code to be read even when partially obscured, but reduce the amount of data that can be encoded.
Common use cases for developers: share a URL without typing it on a mobile device, distribute Wi-Fi credentials to guests, create contactless digital business cards, link physical items (signs, products, packaging) to web pages, and enable two-factor authentication app enrollment.
Common mistakes
- QR code too small to scan — For reliable scanning, a QR code should be at least 2.5 cm × 2.5 cm when printed. If the code encodes a long URL, it requires more cells and needs to be printed larger.
- Low contrast — The finder pattern (the three square corners) and the code cells need sufficient contrast with the background. White-on-light-grey or dark-on-dark codes may not scan reliably.
- Short URL vs full URL — Long URLs create dense QR codes that are harder to scan. Consider using a URL shortener for very long URLs, or better, use a short canonical URL for physical materials.