QR code not scanning? Causes and fixes

1. Check the phone

• QR scanning is switched off. On iPhone, go to Settings → Camera and make sure Scan QR Codes is on. On Android the option lives in the camera app's settings (often called Google Lens suggestions or Scan QR codes) and varies by manufacturer.
• Dirty lens or poor light. Wipe the lens and add light; avoid backlighting.
• Too close or too far. The code should fill a good part of the frame. Move back if the camera can't focus, closer if the code is tiny.
• The code is on your own screen. You can't point the camera at its own display — scan it from the image instead.

Still nothing? Try Google Lens or the browser-based QR reader — if another decoder reads it, the problem is the phone, not the code.

2. Check the design

• Low contrast. Dots must be clearly darker than the background in brightness, not just a different hue. Mid-grey on light grey, yellow on white or navy on black all fail.
• Inverted colours. Light dots on a dark background are not read by many scanners. Use dark on light.
• No quiet zone. The code needs a clear margin — ideally 4 modules — on every side. Text, borders or a busy background touching the code is a classic failure.
• Logo too big. A centre logo only works because of error correction; keep it to roughly 10–15% of the area, use level H, and never cover the three corner squares.
• Over-styled modules. Heavily rounded, tiny or decorative dots, or a gradient that fades toward the background, lower the contrast scanners rely on.

More in design best practices.

3. Check the print

• Printed too small. Use the 10:1 rule — the code's width should be at least a tenth of the scanning distance — and avoid going below about 2 cm. See sizes and print resolution.
• Blurry image. An upscaled low-resolution PNG has soft module edges. Export at the final size or use SVG — see PNG vs SVG.
• Glare. Glossy lamination, screens and shop windows reflect light across the code. Use matte finishes where you can.
• Curved or creased surface. Bottles, cups and folds distort the grid. Print larger, keep the code away from folds and raise error correction.
• Damage and wear. Scratches and dirt accumulate outdoors. Error correction helps, but replace worn codes.

4. Check the content

• Too much data. Long URLs and full contact cards make a dense, fine grid. Shorten the link or point to a web page. See QR code capacity.
• It scans but "doesn't work". The code is fine; the content is wrong — a typo in the URL, a page that was moved, or a Wi-Fi password that changed. Read the raw content with the reader to see exactly what is encoded.
• A dynamic code expired. If the code was made with a subscription service, it may redirect through their server and stop when the plan ends. See can QR codes expire.
• Wi-Fi joins but fails. Usually unescaped special characters or the wrong security type — see the Wi-Fi QR format.

Test before you print

Scan the final artwork — at real size, on the real material — with at least one iPhone and one Android phone, from the distance people will actually stand. Checking a proof costs minutes; reprinting a batch costs much more.

Frequently asked questions