What Is a QR Code?

A QR (Quick Response) code is a two-dimensional barcode — a grid of black and white squares that encodes text, a web address, or other short pieces of data. You've seen them on restaurant menus, product packaging, event tickets, and business cards. Point a phone camera at one, and it decodes almost instantly.

How it's different from a regular barcode

A traditional barcode — the kind on a can of soup — is one-dimensional. It only stores data along a single line, and a scanner has to read it left to right at roughly the correct angle. That limits how much information it can hold: usually just a product number that a database looks up.

A QR code stores data in two dimensions, both across and down the grid. That gives it dramatically more capacity — up to a few thousand characters, depending on the error correction level — and it can be read by a camera from almost any angle or orientation, not just straight-on.

What's actually inside the pattern

The black and white squares (called modules) aren't decorative — each one encodes a bit of binary data. Three of the corners have larger square markers that tell a scanner "this is a QR code, and here's how it's oriented," which is why you can scan one upside down or at an angle and it still works.

Beyond the raw data, a portion of every QR code is dedicated to error correction: redundant information that lets the code still be read even if part of it is dirty, torn, or covered by a logo. That's a deliberate design choice, not a flaw — more on how it works in our error correction guide.

What people actually use QR codes for

How to make one

You don't need a dedicated app or account. A browser-based tool like QRToolCraft converts any text or link into a QR code in a few seconds, lets you add a logo and adjust error correction, and generates the whole thing locally in your browser — nothing you type gets uploaded anywhere.