Why a QR code can tolerate a logo
A QR code does not store the information only once. It encodes it with redundancy: besides the data, it includes error-correction codewords that can rebuild part of the content if the drawing gets damaged. Levels L, M, Q and H recover about 7%, 15%, 25% and 30% of the codewords. A centered logo takes advantage of that margin.
But redundancy is not a license to cover any area. The three large corner squares — the position patterns — tell the camera where the code is and how it is rotated. If you cover them, a reader may fail to find it even though the rest is intact. The same goes for the timing strip and the outer white margin.
The 20–25% rule
The logo should occupy a clear minority of the area. In a 29 × 29-module QR code, a logo covering 12 × 12 modules is already at the limit and removes information in the center, where data usually sits. The longer the content — a URL with parameters, a full vCard — the denser the code becomes and the less advisable it is to cover it.
| Content | Recommended logo | Level |
|---|---|---|
| Short URL | Up to 25% of the area | H |
| Long URL or vCard | Up to 15% | H |
| Text or Wi-Fi | No logo or minimal | Q/H |
There is no universal figure: it depends on the QR version and the print quality. The only serious validation is scanning the final result, not the file on screen.
Contrast, margin and file
- Contrast: dark modules on a light background. A white logo on a black QR code works better than a dark logo on a dark QR code.
- Margin: leave four white modules around it. If the logo touches the border, the reader loses its reference.
- Vector: export SVG or PDF for print. A 512 px PNG enlarged to 20 cm produces irregular modules.
- Gloss: glossy lamination reflects ceiling light; matte scans better on posters and tables.
Five-phone test: print the QR code at its final size and scan it with five different phones, two of them old, at the real distance. If any fails, reduce the logo before the print run.
What to do if the logo is mandatory
If the brand demands a large logo, there are safer alternatives: place it outside the code, next to it, or blend the brand color into the modules without covering information. You can also use a frame with the logo in a corner of the display piece, not inside the drawing. The QR code does not need to carry the brand inside it to be recognizable: the whole piece — poster, table, card — already communicates it.
And if the code is dynamic, remember that the logo does not affect the destination: you can change the URL without reprinting, but a badly printed drawing will not get fixed.
Frequently asked questions
What percentage can the logo cover?
Between 20% and 25% of the area at most; less if the content is long.
Which correction level do I use?
H, the highest, to have room against the logo and wear.
Can I put the logo in a corner?
Not over the position patterns. Better in the center or outside the code.
Does the logo affect the URL?
No. It only affects how readable the drawing is.