How to scan a QR code from a screenshot or photo on Android

Someone sends you a QR code in a chat. A ticket arrives as a screenshot. A menu is a photo. The camera is no use, because the code is on the same screen the camera would need to look at. Here are the ways to read a code that is already on your phone, and the reasons it sometimes fails.

1. Google Lens in the Photos app

Open the image in Google Photos. At the bottom there is a Lens button. Tap it and Lens scans the picture, finds the QR code and shows the result above it: a link to open, text to copy, a Wi-Fi network to join.

This works on almost every Android phone with nothing to install. It needs a connection for most results, and the image goes to Google for processing.

2. Circle to Search

On Pixel phones and recent Samsung phones, long-press the home button or the gesture bar while the code is on screen, then circle it. The result appears below. It works inside any app, so there is no need to screenshot first. Same caveat: online, and processed by Google.

3. Chrome

If the code is on a web page, long-press the image and choose Search image with Google Lens. Chrome sends the image to Lens and shows the link.

4. An offline scanner app

Scanner apps have a scan from image button that opens the gallery. Pick the screenshot or photo and the app decodes it. The difference from the three options above is where the work happens: an app with on-device decoding reads the code on the phone and uploads nothing.

That matters for three kinds of content:

• Wi-Fi codes. The password is in the code. Decoding it locally means it stays local.
• Contact cards. Names, numbers and addresses.
• Barcodes. Lens reads product barcodes too, but a dedicated scanner handles the full set: EAN-13 and EAN-8 on groceries, UPC on American products, Code 128 and Code 39 on parcels and tickets, ITF and Codabar in warehouses and libraries, and the two-dimensional Data Matrix, PDF417 and Aztec on boarding passes and ID documents.

QR Barcode Scanner Generator does it this way. Tap the image button on the scan screen, pick a picture, and the result appears with the same actions as a live scan: connect to the Wi-Fi, add the contact, open or copy the link. Everything decodes on the device and the scan goes into a private history on the phone that you can clear any time.

Why an image fails to scan

The message is usually "no code found in image". The causes, in order of how often they happen:

• Too small. The code is a thumbnail in a big screenshot. Crop so the code fills most of the frame.
• Cut off. All four corners have to be visible, including the three large squares that mark a QR code's position.
• No quiet zone. A QR code needs a white margin around it, about four modules wide. A code cropped right to its edge often fails. Leave a border when you crop.
• A photo of a screen. The pixel grid of the screen and the pixel grid of the camera interfere and produce a moire pattern that hides the code. Take a screenshot instead, or ask for the image file.
• Blur or glare. A photo taken at an angle under a lamp. Retake it square on, in even light.
• Inverted colours. Light modules on a dark background. Most readers expect dark on light. Some cope, many do not. Inverting the image fixes it.
• Damaged code. QR codes recover from up to about 30 percent damage depending on their error correction level. Past that, nothing will read them.

A note on what the code might do

A QR code is a link or a piece of text you cannot read yourself. A code in a screenshot from a stranger deserves the same caution as a link from a stranger. Any decent scanner shows you the content before opening it. Read the domain before you tap.