Reed-Solomon Error Correction Explained: Levels L, M, Q, & H
Learn how mathematical error tolerance works in QR codes. When to choose Level L for minimal density versus Level H for logos and outdoor durability.
QR codes use Reed-Solomon error correction, the same mathematical error-correcting algorithm used on compact discs (CDs) and deep-space satellite transmissions.
Level L (Low): Restores up to 7% of damaged or obscured codewords. It produces the cleanest, least dense pattern. Ideal for short URLs on clean, protected digital displays.
Level M (Medium): Restores up to 15% of damaged codewords. This is the global standard default for most general marketing collateral and flyers.
Level Q (Quartile): Restores up to 25% of damaged codewords. Recommended for outdoor posters and industrial shelf tags exposed to weather.
Level H (High): Restores up to 30% of damaged codewords. This level is essential whenever you embed a company logo in the center of the code, or when printing on high-wear items like floor decals or event wristbands.
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