QR Code Error Correction Levels
Definition: Error correction is a built-in QR code feature that allows the code to be read even when partially damaged, obscured, or covered by a logo.
QR codes use Reed-Solomon error correction with four levels: L (Low, 7% recovery), M (Medium, 15%), Q (Quartile, 25%), and H (High, 30%). Higher error correction means more redundant data, making the code denser but more resilient. Level H is required when placing a logo over part of the code.
Key points
- Level L: 7% damage recovery — smallest code
- Level M: 15% — good default balance
- Level Q: 25% — for moderate wear environments
- Level H: 30% — required for codes with logos
- Higher correction = denser code = larger print needed
Frequently asked questions
Which error correction level should I use?
Use H (30%) if adding a logo. Use M (15%) for general purpose. Use L (7%) for maximum data capacity or clean/controlled environments.
Can I add a logo with Level L?
Not recommended. Level L only recovers 7% of data — a logo covers more than that. Use Level H (30%) or Q (25%) for codes with logos.
Does error correction affect scanning speed?
Not noticeably. Modern scanners process all error correction levels in milliseconds.
Related terms
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