How to use it
- Choose Link, Text or Wi-Fi and fill in the field that appears.
- Pick an error correction level and a size. PNG for documents and messaging, SVG for print and design work.
- Press Generate and download the code, then scan it with your phone to confirm it before printing.
How the code is generated
The content is encoded with a small open-source QR encoder running in your browser, using byte mode with UTF-8, so Arabic, Turkish and any other script scans exactly as typed. The smallest QR version that fits the text is chosen automatically, a four-module quiet zone is drawn around it as the standard requires, and the result is either painted onto a canvas for the PNG or written as a path for the SVG. Nothing is stored and nothing is sent: a Wi-Fi password you type here goes into the image and nowhere else.
Error correction, and which level to choose
A QR code carries redundant data so it can still be read when part of it is dirty, torn or covered. Level L survives about 7 percent damage, M about 15, Q about 25 and H about 30. Higher levels make a denser code, which is harder to scan from a distance or at a small size. M is the right default. Use H if you intend to place a logo over the centre, and L only when the content is long and the code must stay sparse.
Wi-Fi codes
The Wi-Fi option writes the network name, security type and password in the format that both Android and iOS recognise, so scanning the code offers to join the network without typing anything. The password is written into the code in plain text; anyone who scans it has it, so print it where only guests will see it.
Questions
Do these codes expire or need an account?
No. The code contains the content itself, not a link to a service, so it works forever and nobody can switch it off or track scans. That is also why it cannot be edited after printing.
How much text fits?
Up to about 2,900 characters of plain Latin text at the lowest error correction, and less for other scripts and higher levels. A code that long is hard to scan; keep links short and use a URL for anything longer.
PNG or SVG?
SVG scales to any size without blur and is what a printer or designer will ask for. PNG is right for a document, a message or a web page. Both encode the same content.