QR codes that scan from print
Size, error correction, and quiet zones — the three things that decide a scan.
Updated · 4 min read
A QR code that fails in print almost always fails for one of three reasons: printed too small for the scanning distance, error correction chosen wrong for its environment, or the white margin around it invaded by design elements. All three are decisions you make before printing — here's how to get each one right.
Size: the 10:1 distance rule
The working heuristic: a code should be at least one tenth of its scanning distance. Scanned from 30 cm (hand-held flyer), 3 cm is workable — in practice 2–3 cm is the floor for anything hand-held, and business cards should not go below 2 cm. A poster read from 3 meters needs a 30 cm code; signage read from across a street needs to scale accordingly. When in doubt, print a test at final size and scan it with a mid-range phone in bad light — not your flagship in good light.
Density compounds this: every extra character adds modules (the little squares), and more modules at the same
physical size means smaller modules. Short URLs produce coarser, more forgiving codes — one more reason to
encode example.com/r/x2 rather than a 200-character tracking URL.
Error correction: L, M, Q, H
QR codes carry redundancy that lets them survive damage. The four levels can restore roughly L ≈ 7%, M ≈ 15%, Q ≈ 25%, H ≈ 30% of the symbol. Higher isn't automatically better — more redundancy means more modules, which at fixed print size means finer detail. Pick by environment: M for clean indoor print (menus, flyers, packaging), Q or H for outdoor, laminated, or abuse-prone surfaces — and H whenever a logo overlays the center, because that logo is literally consuming your damage budget.
The quiet zone is part of the code
The spec requires a clear margin of 4 modules on every side — scanners use it to find the symbol's edges. The most common print failure we see isn't size at all: it's a designer nudging the code against a colored panel, a border, or body text, and the scanner can no longer isolate it. Keep the margin white (or the code's own background color), and keep contrast high and dark-on-light — inverted codes break on a meaningful share of readers.
Print checklist
- Shortest URL you can arrange; HTTPS included.
- ≥ 2 cm hand-held; ≥ 1/10 of scanning distance otherwise.
- Error correction M indoors, Q/H outdoors or logo'd.
- 4-module quiet zone, dark code on light ground.
- Export as SVG so any print size stays razor sharp, then test-scan the actual proof.
Our generator exports print-ready SVG and PNG with the quiet zone built in, error-correction control, and a Wi-Fi mode for network-join codes — free, in your browser.