More content makes the code harder to scan
How QR codes work
Two-dimensional barcodes include stacked and matrix formats. Stacked barcodes combine multiple rows of linear codes. Matrix codes use a grid of dark and light modules to represent binary data.
Data representation
Dark modules represent binary 1; light modules represent binary 0.
Error correction capacity
- Level L: recovers approximately 7% of data codewords
- Level M: recovers approximately 15% of data codewords
- Level Q: recovers approximately 25% of data codewords
- Level H: recovers approximately 30% of data codewords