What is a QR Code?
A QR Code (Quick Response Code) is a two-dimensional matrix barcode invented by DENSO WAVE in Japan in 1994. Unlike traditional one-dimensional barcodes that store information only horizontally, QR codes store data in both horizontal and vertical directions, enabling significantly greater data capacity.
High Capacity
Can store up to 7,089 numeric characters or 4,296 alphanumeric characters, far exceeding one-dimensional barcodes.
Error Correction
Built-in Reed-Solomon error correction allows the code to be read even when partially damaged or obscured, with up to 30% error recovery.
Fast Recognition
Three finder patterns (corner squares) help scanners quickly locate the code, enabling 360-degree scanning from any angle.
Wide Applications
Widely used in mobile payments, product tracing, business cards, WiFi sharing, URL linking, and many everyday scenarios.
QR Code Error Correction Levels
QR codes have four error correction levels. Higher levels provide better damage tolerance but reduce data capacity. This tool defaults to M level (recommended), balancing error tolerance and capacity:
| Level | Recovery Rate | Best For |
|---|---|---|
| L (Low) | ~7% | Clean environments, when maximum data capacity is needed |
| M (Medium) | ~15% | General use (recommended default) |
| Q (Quartile) | ~25% | Industrial environments or minor damage expected |
| H (High) | ~30% | Harsh environments, or when embedding a logo |