Error correction level
Error correction capability allows to successfully scan a QR Code even if the symbol is dirty or damaged. Four levels are available to choose according to the operating environment.
Higher levels offer a better error resistance but reduce the symbol's capacity.
If the chances that the QR Code symbol may be corrupted are low (for example if it is showed through a monitor) is possible to safely use a low error level such as Low or Medium.
Possible levels are shown below:
| Level | Error resistance |
|---|---|
| L (Low) | ~7% |
| M (Medium) | ~15% |
| Q (Quartile) | ~25% |
| H (High) | ~30% |
The percentage indicates the maximum amount of damaged surface after which the symbol becomes unreadable.