QR Code Error Correction Levels Explained (L, M, Q, H)
Every QR code contains extra data that lets scanners recover the message even when part of the code is dirty, damaged or covered. This is called error correction, and you can choose how much to include.
The four levels
- L (Low): recovers about 7% of the data.
- M (Medium): about 15%.
- Q (Quartile): about 25%.
- H (High): about 30%.
The trade-off
More error correction means a denser pattern with smaller squares. A high level is more forgiving but harder to scan on tiny prints. A low level is simpler and cleaner but fragile.
Which one should you use?
- Clean digital screens: L or M is fine.
- General printing: M or Q.
- Outdoor, stickers or rough surfaces: Q or H.
- With a logo in the center: H, because the logo covers part of the data.
Why logos work
A centered logo hides part of the pattern, and error correction fills the gap. At level H, up to roughly 30% can be unreadable. Loqo sets the level to High automatically when you upload a logo, and keeps the logo between 12% and 28% of the code width. For the full workflow, read how to add a logo to a QR code.
Do not rely on the maximum
The percentages describe ideal conditions. A large logo, low contrast and a tiny print together can still break a code, so always test. See common scanning problems and fixes.
Related guides
- Static vs Dynamic QR Codes: Which One Do You Need?
- SVG vs PNG for QR Codes: Which Format Should You Download?
- How to Make a QR Code Menu for Your Restaurant (Free)
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