How to use the QR code reader
- Upload image: click the drop area, press Enter or Space while it has focus, drag a file onto it or paste with Ctrl+V. Screenshots and photos both work.
- Use camera: switch tabs, press Start camera, allow access and hold the code inside the frame. Scanning stops when a code is read.
- Read What the code contains. It names the type, lists the fields and shows the Raw content. Use Copy content or, for web links, Open link.
- For Wi-Fi codes the tool lists Network name, Security and Password. The password stays hidden until you press Show.
How it reads the code
The first time you scan, the page loads jsQR 1.4.0. It draws your image on a canvas, scales it to at most 3,200 pixels on the long side, finds the three square corner markers, reads the grid of modules and applies Reed-Solomon error correction, which lets a code with level H recover from up to 30% damage, according to Denso Wave, the inventor of the format. If nothing is found, it tries again on halves, quarters and ninths of the picture, so a small code in a large photo, or a picture with several codes, still works and every code found is listed. Camera frames are checked about eight times a second. The decoded text is shown as plain text and is never run or opened for you.
Worked example
Press Scan the sample code. The result is typed as a Link that goes to clicksolvetools.com, and the Raw content is https://clicksolvetools.com. Before you scan anything, the page already shows this result so you can see the layout.
Limits and edge cases
- It reads QR codes only. UPC, EAN and other barcodes need a barcode scanner, and you can make your own with the barcode generator.
- Photos need a sharp, flat code at least about 100 pixels wide. Glare, heavy blur, folds and very low contrast are the usual causes of a miss.
- iPhone HEIC photos do not open in most browsers. Take a screenshot of the picture or save it as JPG first.
- Files over 30 MB are refused. The camera needs a secure page and your permission, and the Upload tab works without either.
- To make a code instead of reading one, use the QR code generator.
Frequently asked questions
How do I scan a QR code from a screenshot or an image on my computer?
Open the Upload image tab and drop the file on the drop area, choose it from the file picker, or copy the image and press Ctrl+V. The decoder runs in your browser, so the image never leaves your computer.
Is it safe to open a link from a QR code?
Not always. The FTC warns that scammers hide harmful links in QR codes, including stickers placed over real ones. This tool shows where a link goes, flags unencrypted, numeric and look-alike addresses, and never opens it for you. Check the address for a switched letter and skip codes you were not expecting.
Why will my QR code not scan?
The usual causes are a small or blurry code, glare, a damaged or folded print, and a code with no blank border around it. Crop the picture tightly around the code, increase the contrast, or retake the photo from straight on.
Can a QR code hold a Wi-Fi password?
Yes. A Wi-Fi code stores the network name, security type and password as text in the form WIFI:T:WPA;S:name;P:password;;. This reader recognizes that format and lists the fields, with the password hidden until you press Show.
Sources: Denso Wave, QR Code error correction; ZXing, Barcode Contents; FTC, scammers hide harmful links in QR codes.