You have probably noticed the scannability of a QR Code despite dirt or damage. And you have also seen QR Codes with a logo. Despite there being a damage or an error, the QR Code scans perfectly fine. This is because of QR Code error correction feature.
QR Codes have error correction capability. This means they can restore the data if the code is dirty or damaged. Hence, a QR Code keeps functioning even when a part of it is removed, damaged or even obscured with a finger.
How does QR Code Error Correction work
Error correction happens by implementation of Reed-Solomon Code. In a nutshell, it adds backup data to the QR Code mathematically.
There are four levels of error correction:
1.Level L: up to 7% error correction capability
2. Level M: up to 15% error correction capability
3. Level H: up to 25% error correction capability
4. Level Q: up to 30% error correction capability
Raising the level improves error correction capability and also makes the QR Code dense.
Besides making the QR Code scannable, error correction also creates a room for creativity. It is error correction that allows you to add logo to your QR Codes. By removing some data from QR Code, it introduces an error. Then the logo is added. Hence, one should always choose a higher level of error correction while creating a QR Code with logo.
How to decide the level of error correction
Factors such as operating environment and QR Code size are important determinants of error correction level.
- In case of an environmental setup such as industries, where QR Code may get dirty, Level Q or H may be chosen. It will help to maintain the scannability despite wear-and-tear
- For general marketing purposes, Level L and M are suitable
High levels of error correction are also recommended as one decides to get a QR Code tattooed. This is because higher the level of error correction, greater the data modules and thus, greater the scannability.
That’s all you need to know about QR Code error correction feature.