What is a QR code?
A quick reference for how QR codes actually work, where the name comes from, and what they're good for — written for anyone who scans them, not just people who build with them.
The short answer
A QR code (short for "Quick Response" code) is a two-dimensional barcode — a grid of black and white squares — that stores data your phone's camera can read in an instant. Unlike the barcodes on grocery items, which only hold a short string of numbers, a QR code can hold thousands of characters: a web address, Wi-Fi credentials, a contact card, plain text, and more.
How a QR code actually works
Three of the four corners of a QR code have a distinctive square-in-a-square pattern — the finder patterns. These let a scanner instantly figure out the code's orientation and size, even if the photo is taken at an angle. The data itself is encoded across the remaining grid using a system called Reed-Solomon error correction, which means a QR code can still scan correctly even if up to 30% of it is damaged, dirty, or obscured by a logo. That's the same property that lets manufacturers safely place a brand logo in the center of a code without breaking it — and it's why a QR code generator lets you choose an "error correction level": higher levels tolerate more damage in exchange for a denser, more detailed-looking code.
What people actually use QR codes for
Sharing something instantly
A link to a website, a Wi-Fi network's credentials, a phone number, an email draft, a calendar event, or a digital business card — anything you'd otherwise have to type out by hand.
Proving something is genuine
A QR code issued against a real database record — like Qrauthix's Simple and Secure QR tiers — can be checked live at scan time, which is what makes product authentication and anti-counterfeiting possible. A plain QR code can't do this on its own; see static vs. dynamic QR codes below.
Static vs. dynamic QR codes
Most free QR code generators — including ours — produce static codes: the content is baked directly into the code itself and never changes. That's perfect for a Wi-Fi password or a one-off event flyer. A dynamic QR code instead points to a service that can redirect, update, or verify the destination after the code has already been printed — read the full comparison on our dynamic vs. static QR codes page.
Make your own
If you just need a QR code for a link, Wi-Fi network, contact card, or event, our free QR code generator makes one in your browser — no account, no payment, and nothing you type is ever stored. If you need QR codes that are verified live against a real product catalog, see how Qrauthix's Simple and Secure QR tiers work instead.
Ready to make one?
Generate a free QR code in your browser — no account needed.