# How to scan a QR code on a computer

> No desktop operating system ships a general QR scanner, so use a browser-based one, upload a screenshot or point your webcam at the code. A client-side scanner decodes the image in the browser without uploading it, shows the text, and needs no installation on Windows, macOS or Linux.

Source: https://useqr.app/docs/scanning/how-to-scan-a-qr-code-on-a-computer · Last reviewed 2026-08-21 · UseQR is free forever, no signup.

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## The quickest route: a browser scanner

Computers do not have a Camera-app-with-a-banner flow the way phones do, but they do not
need one. Open a [browser-based scanner](/scan) and give it the code one of three ways:

- **Upload or drag in an image**: a screenshot, a saved PNG, a photo from your phone.
- **Paste** an image straight from the clipboard.
- **Use the webcam** and hold the code up to it.

A well-built scanner runs entirely **client-side**: the decoding happens in your
browser's own JavaScript, the image never leaves your machine, and nothing is installed.
It also shows you the decoded **text** rather than blindly opening it, exactly what you
want when [checking a suspicious code](/docs/security/how-to-check-a-qr-code-before-opening).
The mechanics of how in-browser decoding works are on the
[browser scanning page](/docs/scanning/qr-scanning-in-a-browser).

## What each operating system gives you natively

| OS | Built-in QR scanning |
|---|---|
| **Windows** | The Camera app includes a barcode mode in recent versions: webcam only, no image files. Details: [scanning on Windows](/docs/scanning/qr-scanning-on-windows) |
| **macOS** | **None.** Preview and Quick Look cannot decode a code. Details: [scanning on a Mac](/docs/scanning/qr-scanning-on-mac) |
| **Linux** | Nothing in the desktop shells; `zbarimg` on the command line is the standard tool. Details: [scanning on Linux](/docs/scanning/qr-scanning-on-linux) |

That table is why the browser route wins: it is the only method that behaves identically
on all three platforms and handles both image files and the webcam.

## The drag-a-screenshot flow

The most common desktop case is a QR code **on the screen**, in an email, a PDF, a
slide, a web page. The camera flow is useless there; the screenshot flow takes seconds:

1. Screenshot the code (Windows: `Win+Shift+S`, macOS: `Cmd+Shift+4`, Linux: your
   screenshot tool).
2. Drag the image into the scanner page, or paste it.
3. Read the decoded text, then open it if it looks right.

Cropping is unnecessary as long as the code is sharp, decoders locate the code within a
larger image on their own.

## Last resort: point your phone at the screen

If a phone is within reach, its camera will read a code off your monitor. It works, but
monitors add glare and refresh artefacts, so raise the screen brightness and hold the
phone square-on. The failure modes of this route have
[their own page](/docs/scanning/scanning-a-qr-code-off-a-monitor).

## Do not install a desktop scanner app

For a one-off scan, a downloaded "QR reader" utility is the worst option on the table:
most are ad-supported, several phone home with whatever they decode, and none of them do
anything a client-side web scanner cannot. The exception is genuine bulk work
(warehouse-style scanning stations), which is better served by
[hardware scanners](/docs/scanning/hardware-barcode-scanners-and-qr).

## FAQ

### Can I scan a QR code without a phone?
Yes. Upload a screenshot or image of the code to a browser-based scanner, or hold the
code up to your webcam. The decoding runs in the browser itself, so nothing is installed
and the image is not uploaded to a server.

### How do I scan a QR code that is on my screen?
Screenshot it (Win+Shift+S on Windows, Cmd+Shift+4 on macOS), then drag the screenshot
into a browser-based scanner. The decoder finds the code inside the image, so precise
cropping is not required.

### Does Windows or macOS have a built-in QR scanner?
Windows has a barcode mode in recent versions of the Camera app, webcam only. macOS has
nothing built in, Preview and Quick Look cannot decode QR codes. On both, a browser
scanner is the practical answer.

### Is it safe to use an online QR scanner?
Use one that decodes client-side, meaning the image is processed in your browser and
never uploaded. It should show the decoded text first rather than opening the link
automatically, so you can read the destination before visiting it.

## Try it

- https://useqr.app/scan
- https://useqr.app/validate