How QR Codes Work and How to Scan Them Safely

A QR code is a square pattern of black and white modules that stores information, most often a web address. Your phone camera reads the pattern and opens the link.

How they work

The code contains data in a standard format, plus error correction so that it still works when partly damaged or covered. Anyone can generate one for free, which is why they are so common.

Everyday uses

• Restaurant menus and event tickets.
• Wi-Fi sharing.
• Payments and boarding passes.
• Linking to apps and product information.

The risks

A QR code does not show you where it leads. Criminals put stickers over real codes on parking meters or posters, or send codes in emails, leading to fake login or payment pages.

Scan safely

• Look at the preview of the link before opening it.
• Be careful if the code is a sticker placed over another one.
• Never enter passwords or card details on a page you reached from an unexpected code.
• Be suspicious of codes that ask you to install an app or urgent payments.
• Use the camera or a trusted scanner rather than random apps.

Create your own responsibly

If you make codes for a business, use a short clear address on your own domain and test it. Printed codes should be checked regularly.

QR codes are convenient, and a moment of checking keeps them safe.