Ever wondered how a QR code with a logo in the middle, or a scuffed corner, still scans? The answer is error correction: extra data stored in the code that lets a scanner rebuild whatever is missing.
The four levels
| Level | Recovers up to | Best for |
|---|---|---|
| L (Low) | about 7% of the code | Clean screens, short links, maximum data |
| M (Medium) | about 15% | Everyday use and most print |
| Q (Quartile) | about 25% | Print that may get scuffed |
| H (High) | about 30% | Codes with a center logo, outdoor or rough use |
The trade-off
Higher error correction means more redundant data, so the code gets denser — more, smaller squares. A denser code needs to be printed larger to stay readable, so do not pick H for a tiny business-card code unless you need it.
Why logos need level H
A logo covers part of the pattern. Level H gives the scanner enough redundancy to reconstruct what is hidden. BestQR switches to H automatically when you add a center icon. Keep the logo to roughly a fifth of the code's width or less, and never cover the three large corner squares. More in our logo guide.
Which level should you choose?
- Plain code, short link, on screen: L or M.
- Printed flyers, menus and cards: M or Q.
- Anything with a logo, or in harsh environments: H.
Error correction is not a license to be careless
It protects against damage, not against poor contrast or tiny print. Check the basics with the color checker and validator, and test every code you print.
Frequently asked questions
What error correction level does BestQR use?
Plain codes use level M. When you add a center logo, the generator switches to level H automatically.
Does higher error correction make a QR code bigger?
It makes the pattern denser, so the same printed width holds smaller squares. Print a little larger if you choose a higher level.
Can a damaged QR code always be recovered?
Only up to the level's limit. Damage to the three large corner squares is more serious than damage elsewhere.