Scanning a QR Code That Is on Another Screen

Codes on computers, TVs and other phones are convenient, but screens have their own problems.

Common problems

• Flicker or stripes. Cameras and screens refresh at different rates, and this can show as moving bands.
• Moiré patterns. Rippling patterns appear when a camera looks at the fine pixel grid of a screen.
• Glare from windows and lights on the glass
• Brightness that is too low or too high
• Small size if the code is tiny on a large screen

Fixes

• Move slightly closer or farther to change the moiré pattern.
• Tilt a little to reduce glare.
• Raise screen brightness on the phone or monitor showing the code.
• Enlarge the code on screen if the page allows it.
• Wait a moment for the scanner to focus.

If you are showing the code

• Increase brightness to maximum.
• Turn off dark mode or any tint that lowers contrast.
• Clean the screen.
• Show the code on a plain white background.

Codes on a TV

A code shown on a TV across a room is often too small. Move nearer or ask whether the code can be displayed larger.

Saved images

If someone sends you a QR code as an image, you can scan it from another device. If you need to scan it on the same phone, some scanners let you pick an image from your gallery.