QR Code Not Working? 30 Reasons & Fixes

Design problems (the most common)

1. Low contrast. Light-gray on white, gold on cream, pastel anything — the camera needs dark modules on a light background. Fix: darken the code, lighten the background.
2. Inverted colors. White code on a dark background fails in many camera apps. Keep the modules darker than the background — always.
3. Missing quiet zone. The white margin (≥4 modules wide) around the code is required. Cropping the code flush against artwork breaks the finder patterns' detection.
4. Logo too big. A center logo over ~20% of the area burns through the error-correction budget. Shrink it — details in QR with logo done right.
5. Too much data. A 500-character URL makes a dense, fragile grid. Shorten the URL (or use a dynamic code — its short redirect keeps the pattern sparse).
6. Over-styling. Extreme module shapes, gradients with light stops, or artistic blending pushed too far. Style, then test on two phones before shipping.
7. Error correction too low for the design. Logos and busy backgrounds need level H (30%). QRolling sets this automatically when you add a logo.
8. Distorted proportions. The code was stretched non-uniformly in a design tool. A QR must stay perfectly square.

Print problems

1. Printed too small. Minimum 2×2 cm for arm's-length scans. Posters need more: rule of thumb — code width ≥ scan distance ÷ 10. Full table in the QR size guide.
2. Low-resolution export. A 200px PNG blown up to poster size = mush. Export SVG (vector) for anything printed.
3. Glossy surface glare. Lamination and glossy paper bounce light straight into the lens. Use matte finishes.
4. Ink bleed. On absorbent paper, heavy ink fattens modules until they merge. Ask the print shop for a test run.
5. Curved or creased surface. Cups, sleeves, and folded flyers distort the grid. Keep codes on the flattest area, sized generously.
6. Faded by sun or wear. Outdoor codes bleach out in months. Reprint, or laminate matte.
7. Printed mirror-flipped. It happens (transfer printing, window decals applied backwards). A mirrored QR never scans.
8. Dark protective sleeve or tinted glass between code and camera kills contrast.

Phone-side problems

1. QR scanning disabled in the camera settings (some Android brands ship it off). Enable "Scan QR codes."
2. Dirty lens. The silent #1. Wipe it.
3. Too close or too far — frame the whole code with margin; let autofocus settle a second.
4. Poor light. Shadows over the code, or a dim room. Add light, or use the flash.
5. Old OS. iPhones before iOS 11 and Androids before ~9 don't scan natively. Use Google Lens or update.
6. Scanning a screen with the same phone. You can't camera-scan your own screen — screenshot it and use scan-from-picture methods or our online scanner.
7. Moiré/flicker from a display. Scanning off a monitor sometimes fights refresh patterns — raise screen brightness, hold farther back.

Destination problems (the code scans, but…)

1. Typo in the URL. The scan works and lands on a 404. Always test the destination, not just the scan.
2. Expired dynamic code. The subscription behind the redirect lapsed — on any provider, the redirect dies. (A code with the destination inside the pattern cannot expire at all.)
3. Link shortener domain blocked or dead. Some shorteners get flagged by corporate networks; if the shortener shuts down, every code through it dies.
4. HTTP instead of HTTPS, or a missing https:// prefix — some phones refuse or mangle it.
5. The destination blocks phones. A desktop-only intranet page or region-locked content fails exactly where QRs are scanned: on phones.
6. WiFi QR with a typo'd password or wrong security type — the scan "works" but the join fails. Regenerate carefully with the WiFi QR generator.
7. Someone stickered over your code. Public codes get maliciously replaced. Check the physical code matches what you printed.

The 60-second diagnostic

1. Scan with two phones (one iPhone, one Android). Both fail → the code/print. One fails → that phone.
2. Scan the digital original on screen. Screen works, print fails → print problem (size, glare, ink).
3. Code scans but the page is wrong → destination problem: fix the URL, or swap it live if it's dynamic.