Scan a QR on a computer from camera, screenshot, image, or PDF
On Windows, open Camera, switch to its barcode or QR mode when available, and hold a printed code in front of the webcam. For a QR already on the computer, take a clear screenshot or save the image, then upload it to QRFlow's browser reader; decoding runs locally and works across Windows, macOS, Linux, and Chromebook. A QR inside a PDF can be captured as an image first. Crop loosely enough to preserve the white quiet zone, avoid a tiny or blurred source, and copy the decoded result before opening it. Treat unknown login and payment codes as sensitive.
Use Windows Camera for a printed code in front of a webcam.
Upload screenshots or saved images to the local reader.
Preserve the quiet zone and inspect sensitive destinations.
在电脑上从相机、截图、图片或 PDF 扫描二维码
在 Windows 上打开相机 App，在支持时切换到条形码或二维码模式，然后把印刷二维码放到摄像头前。二维码已经显示在电脑上时，可以截取清晰截图或保存图片，再上传到 QRFlow 浏览器读取器；解码会在本地完成，适用于 Windows、macOS、Linux 和 Chromebook。PDF 中的二维码可以先截成图片。裁剪时保留二维码周围白色留白区，不要使用太小或模糊的源图；打开目标前先复制并检查解码结果。未知登录码和付款码应按敏感内容处理。
印刷二维码可放在 Windows 相机前读取。
截图或图片可上传到本地读取器。
保留留白区，并检查敏感目标。
How we verify this guide
Before this page is included in the public guide directory, its examples are compared with the payload produced by the linked QRFlow generator and with the export and scan-readiness controls available in the current build. Camera, lighting, paper, print size, and destination apps can still change the result, so important print runs should always be tested on the final material and real devices.
On a computer, the fastest method depends on where the QR code is. Use the Windows Camera barcode mode for a printed code, or decode a screenshot or saved image in the browser on Windows, macOS, Linux, or Chromebook.
Diagnose a business card QR code that won't scan: test the file, then fix size, quiet zone, contrast, glare, blur, vCard density, styling, or print damage.