QR Code Reader

Read QR codes from images.

Upload a QR image and decode it locally in the browser. No uploaded file is sent to a server.

Images are decoded locally. Links are shown as text and never opened automatically.
Decoded textWaiting
-decoded type
Choose an image to begin.

How it works

The image is drawn to a local canvas and QR pixels are passed to a browser-side decoder.

Image data is read with FileReader and decoded in the browser.

Practical examples

  • Choose a phone screenshot to extract a URL as text before deciding whether to visit it.
  • Scan a saved Wi-Fi QR image and copy the decoded payload for review.
  • Use the canvas preview to verify that the selected file contains the entire code rather than a cropped corner.

How to read the result

  • Decoded type classifies common URL, email, phone, and Wi-Fi payloads; everything else is labeled as text.
  • A Not found result means the decoder could not locate a QR matrix in the rendered image.
  • Links are returned as text and are never opened automatically.

Limits and privacy notes

  • Blur, glare, heavy compression, cropping, or low contrast can prevent decoding.
  • The reader scans one still image and does not access the camera.
  • The selected image is decoded in the page and is not uploaded.

Method used

  • FileReader loads the selected image and the page draws it onto a canvas, scaling very large images down to at most 900 pixels per side.
  • The decoder receives the canvas RGBA pixel buffer and searches it for a QR code.
  • Only decoded text and a simple payload classification are shown; the page does not follow URLs or execute payload content.
Safety

Read before opening

  • Decoded links are not opened automatically.
  • Copy and inspect the destination first.
  • Type classification is a quick hint, not a security verdict.
Image quality

Improve scans

  • Use a sharp, uncropped image.
  • Avoid low contrast.
  • Canvas preview confirms the selected file.
Privacy

Local image handling

  • The image is drawn in the browser.
  • No upload is needed for decoding.
  • Clear the file input before scanning another image.

Frequently asked questions

Does the reader upload my image?

No. The selected file is drawn to a canvas and decoded by JavaScript in this page.

Will a decoded link open automatically?

No. URLs are displayed as text so you can inspect them before copying or opening them elsewhere.

Why does a visible QR code sometimes return Not found?

Cropping, blur, glare, low contrast, or aggressive image compression can hide the square patterns the decoder needs.

Can this page scan with my camera?

No. This version reads a selected image file or screenshot only.

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