GUIDE深度 · Deep dive
Why a QR Code Will Not Scan
Failures usually come from blur, glare, cropping, low contrast or inversion. Crop the full code with its quiet zone, brighten/avoid glare, hold the camera steady, and try inverting a reversed code.
Crop to the code plus quiet zone; do not cut corners.
Raise contrast/resolution.
10-30 cm away, hold steady for 1-2 seconds.
Avoid glare/shadows; clean the lens.
FAQ
Can inverted codes scan?
This tool tries both polarities; if it still fails, invert the image.
Can it scan a code on screen?
Yes; raise screen brightness and avoid moiré.