QR codes are pixelated black and white squares that perform magic when we point the cameras on our phones at them—but what’s going on that makes this little spell possible? QR codes are akin to the ...

How big your code should be printed depends on how many characters you “encode” into it. It can take an absolute maximum 7,000 characters, but realistically most people will encode about 20 letters or ...

When you scan a QR code, the QR reader in your phone’s camera deciphers the code, and the resulting information triggers an action on your phone. If the QR code holds a URL, your phone will present ...

*Refers to the latest 2 years of stltoday.com stories. Cancel anytime. QR codes are visual patterns that store data smartphones can read. AP Photo/Vincent Yu Among the many changes brought about by ...