What do QR error-correction levels L, M, Q, and H mean?
Compare the four QR correction levels by capacity, damage tolerance, and logo use.
QR levels L, M, Q, and H can recover approximately 7%, 15%, 25%, and 30% of codewords. Higher correction improves damage tolerance but creates a denser symbol for the same input.
What changed in this update?
Level selection was rewritten around logo use and data density.
Which level fits each use?
M is a balanced default for clean digital use. Consider Q for packaging, outdoor use, or a small logo. H suits higher damage risk; L fits controlled cases where capacity matters most.
Is higher error correction always better?
No. Higher levels require more modules for the same data. At a fixed physical size, those modules become smaller and can be harder to scan from a distance.
How do logos interact with correction?
Q or H provides recovery margin when a logo covers the center, but finder patterns, the quiet zone, and large data areas must remain clear.
Frequently asked questions
What should the default level be?
M is a practical starting point for general use.
Does H mean I can cover 30% of the image?
No. The percentage is approximate codeword recovery, not a guarantee that any 30% area can be hidden.