Breakthroughs, discoveries, and DIY tips sent every weekday. Terms of Service and Privacy Policy. Quick Response (QR) codes were popular before the COVID-19 pandemic ...

QR codes — or "Quick Response" codes — are square-shaped barcodes that can be scanned by mobile devices. They are used for a variety of applications, from pulling up a restaurant menu to directing ...

This story originally featured on Popular Science. Quick Response or QR codes were popular even before the coronavirus pandemic, but now they’re everywhere: from restaurant menus and tickets, to ...