QR Code Generator

A QR code is a two-dimensional grid that encodes text. When someone points a camera at it, the app reads the pattern back into that text and acts on it — opening a URL, joining a WiFi network, or starting an email. Everything about the behaviour comes from the encoded string, which is why the content type you pick matters: a link is stored as a plain URL, a WiFi code as a "WIFI:T:WPA;S:network;P:password;;" string, an email as a "mailto:" URL, and an SMS as "SMSTO:". Scanners recognise those prefixes and offer the right action.

The codes generated here are static. The destination is baked into the pattern itself, so the code works forever, cannot expire, and reports nothing back to us or anyone else. That is the important difference from most "free" QR generators, which quietly produce dynamic codes: those encode a short redirect URL on the provider's domain, which lets them count scans — and lets them break every printed code you own if they change their pricing or shut down. A static code has no such dependency.

Error correction is the setting people most often get wrong. QR codes use Reed–Solomon coding to stay readable when part of the pattern is damaged, and you can choose how much redundancy to include: Low recovers about 7%, Medium 15%, Quartile 25% and High 30%. Higher levels need a denser grid for the same content, so they produce a busier code. Medium is right for almost everything. Go to High only if you plan to place a logo over the centre or print onto a surface that will scuff.

Two other things decide whether a code actually scans in the real world. The quiet zone — the blank margin — must be there; scanners use it to find the code's edges, and a code cropped tight to the pattern often fails. And contrast has to be strong, with a dark pattern on a light background. Inverted codes (light on dark) fail on many readers, so if you are colouring the code, darken the foreground rather than lightening the background.

For anything going to a printer, download the SVG. It is vector, so it scales from a business card to a billboard with perfectly crisp edges, whereas a PNG enlarged past its pixel size develops soft, unreliable borders. As a rule of thumb, a printed code should be at least 2×2 cm, and larger if it will be scanned from more than arm's length.