Quick Response Codes were developed in 1994 by Toyota’s subsidiary Denso Wave to allow automotive components to be scanned at high speed. QR Codes provide an easy way to print machine-readable information on paper. In its most compressed form, a single QR code contains several thousand characters.
QR codes have recently become popular also as a simple means to feed information into smartphones, usually web addresses, from newspapers, subway advertisements or museum displays. Special apps can read and decode the QR Code through the smartphone’s camera, and automatically open the related web page in the smartphone’s web browser.
Beware that QR Codes can be malicious. Since they are impossible to decode with the human eye, there is no way for you to determine if the web page that will open in your device is the one you expect, or if it’s safe. We recommend scanners with built-in web security checks, e.g. Norton Snap or QR Pal, both available both for iOS and Android devices.
If you don’t have a QR Code scanner in your device, visit the app store and download one of the many alternatives. Before you install a QR Code reader, consider the following:
Start your QR Code scanning app and wait for the camera to power up. If your device has more than one camera, e.g. front and back, ensure you’ve selected the back camera so that you can focus the camera on the barcode using the display on the front.
When your display shows the image from the camera, point it at the QR Code. Try to get as close as you can. You should be able to see how the camera automatically adjusts its focus and scans the code. The QR Code is automatically corrected for read errors, so it’s unlikely that you will get an incorrect reading.
When the app has decoded the QR Code, the URL is usually displayed on the screen. Some QR Code readers decipher shortened URLs (beginning with domain names like bit.ly, ow.ly or goo.gl), which makes it easier for you to verify the true destination address. QR Code readers with reputation control will also give you a report on the reputation of the site you will be visiting.
If you feel secure that the address you just scanned is safe, approve it and watch it open in your smartphone’s web browser.
Many laptops have built-in cameras above their screens to facilitate video conference calls. Such web cameras can also be used to scan barcodes from another computer’s screen to open a particular web page in the laptop.
The easiest way to scan a barcode from a computer screen with a laptop is to hold the laptop upside down with the camera pointing at the barcode image on the screen. It doesn’t matter that the QR code is upside-down.