QR Code Won't Scan

If your QR code isn't scanning properly, follow this troubleshooting guide to identify and fix the issue.

Quick Checklist

Before diving deeper, verify these common issues:

  • QR code is printed large enough (minimum 2cm × 2cm)
  • There’s sufficient contrast between colors
  • The image isn’t blurry or pixelated
  • There’s a quiet zone (white space) around the code
  • The destination URL is valid and working
  • The phone camera is clean and functioning

Common Causes and Solutions

1. QR Code Too Small

Problem: The QR code is printed or displayed too small to scan reliably.

Solution:

  • Minimum size: 2cm × 2cm (0.8” × 0.8”) for scanning at 10cm distance
  • For distance scanning, use this formula: Size = Distance ÷ 10
    • 1 meter away → 10cm QR code
    • 3 meters away → 30cm QR code

How to fix:

  1. Download the QR code at a larger size (512px or 1024px)
  2. Reprint or resize the image
  3. Use SVG format for unlimited scaling without quality loss

2. Poor Color Contrast

Problem: The foreground and background colors are too similar, making the code hard to read.

Solution:

  • Ensure at least 40% contrast difference between colors
  • Dark colors work best for the foreground (dots)
  • Light colors work best for the background

Good combinations:

  • Black on white ✓
  • Dark blue on white ✓
  • Black on light yellow ✓

Bad combinations:

  • Yellow on white ✗
  • Light gray on white ✗
  • Red on dark red ✗

How to fix:

  1. Edit your QR code in SnapGlyph
  2. Choose higher-contrast colors
  3. Re-download and replace the old code

3. Inverted Colors

Problem: Light foreground on dark background can confuse some scanners.

Solution: While some modern scanners handle inverted codes, many don’t. Always use:

  • Dark foreground (dots)
  • Light background

How to fix:

  1. Edit your QR code
  2. Swap the foreground and background colors
  3. Regenerate the code

4. Missing Quiet Zone

Problem: Content or borders are too close to the QR code edges.

Solution: Every QR code needs a “quiet zone”—empty space around all edges:

  • Minimum: 4 modules (the small squares that make up the code)
  • Recommended: 10% of the QR code size on each side

How to fix:

  1. Add padding/margin around the QR code when placing it
  2. Avoid borders that touch the code
  3. Keep other design elements away from edges

5. Low-Quality Image

Problem: The QR code appears blurry, pixelated, or distorted.

Causes:

  • Downloaded at too small a size then enlarged
  • Heavy JPEG compression
  • Multiple rounds of saving/compression
  • Stretched or skewed during placement

Solution:

  1. Download from SnapGlyph at the largest size you need
  2. Use PNG or SVG format (not JPEG)
  3. Never stretch or skew the code—always maintain 1:1 aspect ratio
  4. For print, use at least 300 DPI

6. Physical Damage or Obstruction

Problem: The printed code is damaged, dirty, or partially covered.

Solution:

  • Replace damaged codes
  • Clean dirty surfaces
  • Ensure nothing covers any part of the code
  • Consider lamination for outdoor codes
  • Use QR code stickers designed for durability

7. Complex Pattern Issues

Problem: Certain styling patterns may reduce scannability on older devices.

Solution: If using decorative patterns:

  1. Test with multiple devices before printing
  2. “Square” pattern has highest compatibility
  3. “Dots” pattern may have issues with some scanners
  4. Rounded corners are generally fine

8. Destination URL Issues

Problem: The QR code scans but shows an error or wrong page.

Check:

  • Is the URL correct? (typos happen)
  • Is the destination website working?
  • Does the URL require login?
  • Has the page been moved or deleted?

How to fix:

  1. Test the URL directly in a browser
  2. Edit the QR code to update the URL
  3. With tracking enabled, the QR code updates automatically

Testing Your QR Code

Before Printing

  1. Test on multiple devices:

    • iPhone and Android
    • Old and new phones
    • Different QR scanner apps
  2. Test at different distances:

    • 15cm (6 inches)
    • 30cm (12 inches)
    • Expected viewing distance
  3. Test in different lighting:

    • Bright light
    • Dim light
    • Direct sunlight (for outdoor codes)

After Printing

  1. Scan the actual printed code
  2. Test from the distance people will use
  3. Check the destination loads correctly
  4. Verify tracking is working (if enabled)

Scanner Recommendations

If you’re having trouble scanning, try these apps:

iPhone:

  • Built-in Camera app (iOS 11+)
  • Built-in Code Scanner in Control Center

Android:

  • Google Lens
  • Built-in camera app (most modern Android phones)

Both:

  • Google app (has built-in QR scanner)

When Tracking Codes Don’t Work

If QR codes with tracking enabled aren’t working:

  1. Check the tracking URL: Go to SnapGlyph and verify the tracking URL is active
  2. Test the redirect: Visit the tracking URL directly in a browser
  3. Check destination: Ensure the final destination URL is valid
  4. Server status: Check if SnapGlyph services are operational

Getting Help

If you’ve tried everything and the code still won’t scan:

  1. Screenshot the issue: Show the code and error (if any)
  2. Note the device: What phone/scanner are you using?
  3. Contact support: Include QR code ID and screenshots
  4. We’ll help: Our team can analyze the code and suggest fixes

Prevention Tips

To avoid scanning issues in the future:

  1. Always test before printing in bulk
  2. Use high contrast colors
  3. Download at proper size for your use case
  4. Use SVG for print materials
  5. Keep URLs short when possible (shorter = simpler code = easier scan)
  6. Use tracking so you can update URLs without reprinting

Next Steps