TROUBLESHOOTING · · BY QRVISUAL
QR Code Not Scanning? A Step-by-Step Troubleshooting Guide
Quick answer: First decide whether the camera cannot read the pattern or the scanned destination does not work. Test the original downloaded file, then change one design or link problem at a time.
Separate a scan failure from a link failure
If the phone recognizes the code and shows a link, the pattern was decoded. A missing page, login screen, expired domain or blocked connection is a destination problem. Open the exact decoded URL in a browser. If no content is recognized at all, investigate the image and scanning conditions first.
Use this diagnostic order
- Test the original export. Upload the PNG to the image scanner. A cropped screenshot or heavily compressed chat image is a different file.
- Restore the border. Leave clear space on every side. DENSO WAVE specifies a four-module quiet zone for ordinary QR codes; a module is one small square in the pattern.
- Restore classic contrast. Use dark modules on a plain light background. Remove photographic backgrounds and decorative filters.
- Remove the logo temporarily. If scanning returns, simplify the logo treatment and test a higher error-correction level.
- Increase the physical size. Test a printed sample from the distance people will actually use.
When the screen preview works but the print does not
Check whether the printer or design program stretched the image. Glossy lamination can reflect overhead lights; folds can cut through a corner marker; a curved bottle can distort a pattern that looked fine on a flat monitor. Move the code away from seams and high-curvature areas. Ask the printer for a sample on the real material before a full run.
A larger PNG or an SVG export can help when the artwork was enlarged beyond its original resolution. Neither can repair a poor destination or guarantee a scan at every viewing angle. The PNG versus SVG guide explains how to choose the source file.
When image upload works but camera scanning does not
Check camera permission for the HTTPS site, clean the lens, improve lighting and hold the complete code in view. Try the phone's normal camera as a comparison. If another application is using the camera, close it and try again. Do not share an unfamiliar decoded link without reviewing its address.
When the code scans but opens the wrong thing
Return to the generator and inspect the content field. A social QR opens the profile URL shown in the form, not the display name printed beside it. A PDF QR opens a public link; it does not contain an uploaded PDF. A static code cannot be changed after export, so regenerate it when its encoded content is wrong.
For a batch, test several rows and compare the filenames with the spreadsheet. Save one known-good export so you can distinguish a generation issue from later image editing.
Sources and further reading
Related guides
Something unclear or a step that did not work? Contact QRVisual or suggest an improvement.