Design causes
If multiple phones fail even on a large, sharp screen preview, start with design. Quiet zone, contrast, finder clarity, logo obstruction, and extreme module styles are frequent culprits.
- Quiet zone too small or invaded by nearby art (measure in modules, not a fixed pixel habit)
- Low contrast, gradients washing out modules, or inverted light-on-dark schemes
- Logo too large for the matrix density—remember 10–35% UI range is not a safety rating
- ECC too low for logo/damage expectations, or ECC so high that modules became tiny at your print size
- Decorative frames or text overlapping the symbol (QRburst does not offer composed frame/CTA export—keep CTA text outside the code)
Capture and print causes
If the code works on screen but fails on paper—or works only when you hover very close—suspect physical size, resolution handoff, blur, compression, glare, or curved substrates.
- Artwork too small for distance or for a high QR version (dense modules)
- PNG exported too small for the inches it was placed into; SVG resampled poorly downstream
- JPEG/PDF compression smudging module edges
- Gloss laminate reflections under spotlights
- Cropping during layout that eats the quiet zone
| Observation | Try next |
|---|---|
| Must stand very close | Increase physical size; shorten payload if version is high |
| Works on matte proof, fails on gloss | Matte finish or reposition lighting/code |
| Edges look soft in print PDF/PNG | Raise DPI or prefer SVG placement; avoid extra recompression |
| Fails only at an angle | Enlarge; reduce perspective stress; check mounting flatness |
Destination vs decode
Sometimes the QR is fine: the phone decodes instantly, but the page 404s, the certificate warns, the Wi-Fi password is wrong, or a redirect chain confuses users. That is not a quiet-zone problem.
Confirm the decoded string matches what you intended. For URLs, open them. For Wi-Fi, remember credentials are plaintext to anyone who scans—and a “failure to join” may be network policy, not QR artwork.
- Decode success + bad page → fix hosting/DNS/HTTPS, not module style
- Users report “nothing happens” → some apps need an explicit open step; check UX copy near the code
- Intermittent redirects → test the live short link or CMS slug separately from the QR image
Fix checklist
Work top to bottom until scans stabilize across two phones and, for print jobs, a physical proof.
- 1. Decode the current image—does any decoder return the exact payload?
- 2. Restore high-contrast dark-on-light solids; protect finders
- 3. Set quiet zone to Generous (4 modules) unless layout truly cannot spare it
- 4. Reduce logo size; keep ECC at H for logo codes; clear logo background on
- 5. Shorten the payload or increase physical size if density is high
- 6. Re-export with appropriate DPI or SVG; avoid recompression
- 7. Run P3 analysis and P4 stress tests in QR Lab as layered evidence
- 8. Proof-scan the final physical output at real distance and lighting