A friend forwards you a photo of a menu board with the code in the corner. Your camera cannot scan a code that is already sitting on your own screen, and pointing the phone at a mirror is not the answer. This gap, between a code in the world and a code in a file, is the one Google Lens fills better than anything else on a phone.
Lens accepts images, not just scenes
The camera scanning you are used to is a live decode. Video frames stream past, a decoder looks for the three corner squares, and the moment it locks on, a notification appears. That pipeline needs a physical code in front of the lens.
Lens works differently. It takes a still image, from the camera or from storage, and analyzes it for anything it recognizes, with codes among the things it can read. That single design difference is why Lens handles screenshots, saved photos, and pictures somebody sent you, which the plain camera cannot touch.
From the camera on many Android phones
On a lot of Android devices, Lens is reachable from inside the camera app: a mode, an icon, or a shortcut you tap before you frame the shot. Where it sits depends entirely on the phone maker, the Android version, and the version of the apps installed, and manufacturers rearrange their camera interfaces regularly. Treat it as "there is probably a way in from the camera on this phone" and go looking, rather than following a fixed sequence of taps from any tutorial.
Worth knowing before you hunt: on most modern Android phones, the plain camera already recognizes codes on its own. If you are pointing at a physical poster, you may never need Lens at all. Our guide to scanning a QR code covers the built-in paths on each platform.
For a photo or screenshot you already have
This is the case Lens was made for. Open the image in your photo app and look for the option that analyzes the picture. On many Android devices, that capability is built into the gallery app directly, and the result comes back as a highlighted region over the code with the decoded content underneath.
Availability again varies by device and app version. When it is missing, or when the image lives on a machine that has no Lens at all, an upload-based tool does the same job in a browser tab: scan a QR code from a picture takes the file and returns the content without installing anything.
On an iPhone
Lens is not part of the iOS camera. It arrives through Google's own apps, so the entry point is inside the Google app or Chrome rather than anywhere in the system camera. Which of those apps exposes it, and where the control sits, shifts with app updates, so look for the image-search style action inside whichever Google app you have installed.
Recent versions of iOS can also detect codes inside images in the photo library without any of that, using the system's own text and object recognition. Version differences matter here, so check what your phone does before installing anything: it may already handle the screenshot you are trying to read.
On a desktop, through Chrome
For a code embedded in a web page, Chrome on the desktop has the shortest path. Right-click the image and choose the Lens-style search action in the context menu. The side panel that opens will surface the decoded content when it recognizes a code, and you can follow it from there without picking up your phone.
That covers images already on a page. For a code arriving as a file attachment, a PDF, or something on a webcam-visible sheet of paper, scanning on a computer covers the upload and webcam routes. A browser-based QR code scanner handles both without an install.
When the plain camera is the better tool
Lens is not always the fast option. For a physical code in front of you, the built-in camera wins: it decodes locally in a fraction of a second, and the notification appears before Lens would have finished uploading anything.
Use the camera for posters, menus, packaging, and event tickets that exist as objects. Use Lens, or an upload tool, when the code is already an image: a screenshot, a saved photo, a picture in a message thread, a scanned document.
There is a third case that deserves a different tool entirely. When you did not choose the code yourself, and especially when it appeared in a message from someone you do not know, a QR code reader that shows you the destination as text before it opens anything is the safer instrument. Reading a code without opening the link explains why the preview step is worth the extra two seconds.
Lens is a cloud service, and that matters
Recognition in Lens happens on Google's servers, not on your phone. The image, or a processed version of it, generally leaves the device to get an answer back. For a menu board that is a non-event. For a screenshot, it deserves a second of thought, because you are sending the entire picture, not the part you care about.
Think about what else is in the frame. A screenshot of a conference badge might include the attendee list behind it. A screenshot of a payment request might include a bank balance in the status area, an email address, or a colleague's name in a notification banner. You uploaded all of it, not just the black-and-white square.
Google publishes what it does with Lens images in its own help and privacy documentation, and those terms get revised, so read the current version rather than a summary written by anyone else. The alternative when the image is sensitive is a decoder that runs locally, either on the device or inside your browser tab, so nothing is transmitted at all.
Next time a screenshot arrives with a code in it, crop the image down to the code and its white margin before you send it anywhere, then decode that crop instead of the full screenshot.
