QR & Barcode

QR codes and barcodes: tiny images that carry real data

A barcode is a way to store text as a pattern of light and dark that a camera or laser can read faster and more reliably than a human typing. The tools here let you create that pattern for a link, a contact, a WiFi network, or a product SKU — and read one back the other way. The leap from old-style stripes to the square QR code is mostly about how much you can pack in and how robustly it survives a scan.

What actually lives inside the squares

A QR code is not magic; it is a grid of black and white modules encoding bytes. The three big squares in the corners are finder patterns that tell a scanner where the code is and which way is up, so it reads correctly even when held at an angle or rotated. The rest is your payload plus formatting bits. Crucially, a QR code stores meaning by convention: a string starting with WIFI: tells a phone to offer to join a network, a BEGIN:VCARD block becomes a contact, and a plain https://link opens a browser. The square itself is dumb — the phone's operating system interprets the text it finds.

Error correction is why a scuffed code still works

The single cleverest thing about QR codes is built-in redundancy. Using Reed–Solomon error correction, the encoder adds extra data so the code can be read even when part of it is dirty, torn, or covered by a logo. There are four levels — L, M, Q, and H — recovering roughly 7%, 15%, 25%, and 30% of the code respectively. That is why a logo can sit in the centre of a marketing QR code without breaking it: the extra correction data fills in for the obscured modules. Higher correction means a denser, busier code, so it is a trade-off between resilience and how small you can print it. Our generator lets you pick the level directly.

Scanning, and where 1D barcodes still win

QR codes are two-dimensional, so they hold hundreds of characters; classic 1D barcodes like EAN-13 and Code 128 hold only a short number or string but scan instantly from a fixed laser at a checkout. That is why retail still runs on stripes while posters and packaging moved to QR. Reading happens entirely on-device with our open-source QR code decoder— your camera frame is analysed locally and never uploaded, which matters when the code contains a WiFi password or personal contact details.

Which tool do I need?

The right tool depends on what should happen when someone points a camera at the code. If you want a scan to open a web page or show plain text, the QR code generator is the general-purpose starting point. To let visitors join your WiFi without typing the password— the classic café, rental, or guest-room case — use the WiFi QR code, which builds the credential string for you. For a scan-to-save business card on a badge, signature, or trade-show stand, the vCard contact QRdrops your details straight into a phone's address book, while the SMS QR code is built for text-to-join campaigns and feedback prompts where a scan opens a ready-addressed message.

Selling a physical product? You almost certainly want a 1D barcode (EAN, UPC, or Code 128) rather than a QR code, since checkout lasers read those. And when you are handed a code and want to know what is inside it before trusting it, the QR code decoder reads the payload on your own screen first.

Popular QR & barcode tools

• QR Code Generator
• WiFi QR Code
• vCard Contact QR
• SMS QR Code
• Barcode Generator
• QR Code Decoder