QR Code Not Scanning? 15 Reasons Why and How to Fix Them

Nothing is more frustrating than a QR code that won't scan. Whether you created it yourself or are trying to scan someone else's code, this guide covers the most common problems and solutions.

1. QR Code is Too Small

Problem: The QR code is too small for cameras to read the pattern clearly.

Solution: Follow the 10:1 distance-to-size ratio. A QR code should be at least 1/10th the scanning distance. For business cards, minimum 2×2 cm. For posters scanned from 2 feet away, at least 2×2 inches.

2. Low Contrast Colors

Problem: Light colors on light backgrounds or dark on dark make it hard for scanners to detect edges.

Solution: Maintain at least 40% contrast. Dark foreground on light background works best. Classic black on white is most reliable.

3. Inverted Colors

Problem: White QR code on dark background may not scan on all devices.

Solution: Always use darker colors for the QR pattern and lighter colors for the background. Some older scanner apps don't support inverted codes.

4. Missing Quiet Zone

Problem: No white space around the QR code makes it hard for scanners to detect where the code ends.

Solution: Maintain a quiet zone at least 4 modules wide (about 0.25 inches) on all sides. Don't let text or images touch the code.

5. Blurry or Low Resolution

Problem: Resizing a small image made the code pixelated and unreadable.

Solution: Always use vector formats (SVG, EPS) for print. Download at 300 DPI minimum. Never scale up a small PNG.

6. Too Much Data Encoded

Problem: Long URLs or lots of text create dense patterns that are hard to scan.

Solution: Use URL shorteners for long links. Keep text minimal. Consider dynamic QR codes for complex data.

7. Physical Damage

Problem: Scratches, stains, fading, or wear damaged the printed code.

Solution: Use higher error correction (Level H: 30%) for codes in harsh environments. Laminate important codes. Replace damaged ones.

8. Poor Lighting

Problem: Too dark, glare, or shadows prevent proper scanning.

Solution: Ensure adequate lighting. Avoid glossy surfaces that cause glare. Position codes away from direct sunlight reflection.

9. Broken or Expired Link

Problem: The code scans but the website doesn't load (404 error).

Solution: The QR code itself works—the issue is the destination. Check the URL is correct and the page exists.

10. Camera Issues

Problem: Dirty lens, focus problems, or old camera hardware.

Solution: Clean your camera lens. Hold the phone steady. Make sure the whole code is in frame. Try moving closer or further.

11. QR Scanning Not Enabled

Problem: Phone's native camera doesn't have QR scanning enabled.

Solution: iPhone: Settings → Camera → enable "Scan QR Codes". Android: Usually enabled by default, or use Google Lens.

12. Outdated Operating System

Problem: Older phones may not have native QR scanning.

Solution: Update to iOS 11+ or Android 9+. Or download a dedicated QR scanner app from the app store.

13. Custom Design Covers Critical Areas

Problem: Logo or design covers finder patterns (the three large squares in corners).

Solution: Never cover the three corner squares. Keep logos in the center. Don't obscure more than 30% of the code.

14. Curved or Distorted Surface

Problem: QR code printed on a curved surface (bottle, mug) is distorted.

Solution: Use higher error correction. Make the code larger. Position it on the flattest part of the surface.

15. Corrupted QR Code Data

Problem: The QR code was generated incorrectly or contains invalid data.

Solution: Regenerate the QR code using a reliable generator. Test before printing. Verify the encoded data is correct.

Quick Troubleshooting Checklist

• ✓ Is the code at least 2×2 cm?
• ✓ Is there high contrast between colors?
• ✓ Is there white space around the code?
• ✓ Is the code clear and not blurry?
• ✓ Is the camera lens clean?
• ✓ Is there good lighting without glare?
• ✓ Have you tested with multiple devices?
• ✓ Does the destination URL work?