QR code generator

A code that never expires

What you type is written into the code itself. A phone that scans it reads your link directly: nothing passes through this site, so there is nothing here that could expire, be switched off or be counted. The code works for as long as the page it points to exists.

That is the difference with the “dynamic” codes sold by subscription, which point to the vendor’s address and redirect from there. They can be edited after printing and they report scans; they also stop working when the subscription does.

Error correction

Every QR code carries spare information, so a reader can rebuild what a scratch, a fold or a glare has hidden. The level sets how much: more correction makes a tougher code, and a denser one for the same content.

Printing it so it scans

Keep the clear margin around the code: the standard asks for four modules of it, and the files this page gives you include it. Print dark on light. A code with light modules on a dark ground is read by many phones and refused by others. Give a printed code at least 2 cm (about 0.8 in) across for something held in the hand, and one tenth of the distance it will be read from beyond that.

Use the SVG for print: it is a drawing, sharp at any size. The PNG is for places that only take images. Whatever you choose, scan the printed proof with two different phones before the print run.

Shorter content makes a coarser, sturdier code. If you are sharing a Wi-Fi network, a long random key from the password generator costs nothing to the people scanning it.