Scan a menu, a Wi-Fi sign, a ticket — a square of dots opens the right page. That square is a QR code. This post explains how it works and how to make one.
1. What is a QR code
QR (Quick Response) is a 2D barcode that stores text or a link in a grid of black/white modules. A phone camera reads it instantly and acts on it — open a URL, join Wi-Fi, add a contact.
2. How it stores data
The pattern uses finder squares (the three big corners) for orientation, then encodes data in the remaining modules with error-correction. That correction lets a slightly dirty or partial code still scan — handy on screens and prints.
3. What can you put in it
- A URL — the most common use.
- Plain text, an email, a phone number.
- Wi-Fi credentials (SSID + password) for guests to join instantly.
- vCard contact info.
4. Make one free, in your browser
Jisubao's generator turns text or a URL into a scannable QR image you can download. It runs locally in your browser — what you enter stays on your device. Paste, click generate, save the image.
👉 Try it now: Jisubao QR Code Generator →
5. Tips for a clean scan
- Keep high contrast: dark modules on a light background.
- Don't shrink too much; small codes are harder to scan.
- Test with your own phone before printing.