Most people know how to point a phone camera at a QR code. The harder case is a code that is already on your phone: a screenshot someone sent you, a photo in your gallery, or a code on a web page. You cannot point a camera at your own screen, so here is how to scan it instead.

Scan a QR code from a photo or screenshot

Install a QR scanner that can read images. I use QR Code Scanner: Barcode Maker , which is free on Google Play.

Open the app and tap the gallery button next to the camera view.

Pick the screenshot or photo that has the code.

The app reads it and shows what is inside: a link, a WiFi network, a phone number, a contact card or plain text.

That is all. No second phone and no printing.

Scan a code in the dark or from far away

If the code is on a poster across the room or in a dim restaurant, two things help. Turn on the flashlight with the torch button, and use the zoom slider to bring a small code closer.…