QR Studio test-scans every design as you edit it. If the badge says May not scan, follow the suggestions it shows.
Contrast
Scanners need a dark code on a light background. Aim for a contrast ratio of 4:1 or higher (shown in the preview). Light-on-dark ("inverted") codes work on modern phones but fail on some older scanners.
Logos
Logos hide part of the code. Lynqr removes the modules under the logo cleanly and locks error correction to High, which can recover about 30% of the code. Keep logos at or below ~25% of the code width, and use a badge (circle or rounded square) so the logo stands apart.
Error correction
| Level | Recovers | Use when |
|---|---|---|
| L | ~7% | Clean screens, smallest code |
| M | ~15% | Default for most uses |
| Q | ~25% | Outdoor or rough surfaces |
| H | ~30% | Logos, stickers that may scuff |
Higher levels make the pattern denser, so print slightly larger.
Quiet zone
Leave blank space around the code: at least 2 modules (the default), and 4 for print. Frames add their own padding.
Print size
A good rule is scan distance ÷ 10. A code scanned from 30 cm should be at least 3 cm wide. Dense codes (long URLs, big vCards) need more space. Dynamic codes stay small because they only encode a short address.
Formats
- SVG: infinitely scalable, for designers and large prints.
- PDF sheet / card: print-ready, vector.
- PNG: up to 4096 px, transparent background supported.
- JPEG: solid background, for tools that don't accept PNG.