QR Code Generator
Input text or URL to generate QR code instantly.
How to Use
- Enter a URL or text in the input field.
- Click "Generate" — the QR code appears instantly below.
- Scan with any device or click "Download" to save the PNG.
How It Works
A QR code is basically a black-and-white checkerboard. Black squares represent 1, white squares represent 0 — it stores data in binary. The three big squares in the corners are "position markers" — your phone finds them first to determine the code's orientation and size. The rest of the grid is your data, protected by error correction encoding. Even if up to 30% of the code is damaged, it can still be scanned. This tool uses the qrcode.js library, running entirely in your browser.
Tips & Tricks
- • Leave enough white margin around the QR code (at least 1/10 of the code width)
- • High contrast works best — dark background, light foreground
- • If printing on business cards, test it with a real scan first — screen clarity doesn't guarantee print clarity
FAQ
How much data can a QR code hold?
Up to 4,296 characters (alphanumeric) or 7,089 digits. For Chinese characters, about 1,000+ characters. More than enough for a URL.
Do QR codes expire?
The QR code itself never expires — it's a static image. But if the link it points to is deleted or changed, scanning it leads nowhere. So "expired" QR codes are really just broken links.
Why won't my QR code scan?
Common reasons: the code is too small, lighting is dim, the code is wrinkled or dirty, or the camera isn't focused. Also, if your error correction level is too low and a logo covers too much, it won't scan.
Real-World Example
Zhang runs a small restaurant and was tired of reprinting menus every time he changed dishes. He put his menu online and printed QR codes on every table. Customers scan to browse the digital menu, and updating dishes costs nothing. "Five minutes to generate the QR code, saved six months of printing costs."