QR code generator

About the QR Code Generator

Introduction

A QR code stores text in a square grid of dark and light modules that any phone camera can read. This generator creates codes for links, plain text, Wi-Fi logins, contact cards, e-mails, text messages, phone numbers and map locations. You can change the colours, use rounded or dot-shaped modules, add your logo and download the result as PNG for documents and the web or as SVG for print. It also works the other way round: drop a screenshot or photo and the code in it is decoded.

How to use it

1. Choose what the code should do – open a link, join a Wi-Fi network, save a contact … – and fill in the form. The code updates as you type.

2. Optionally adjust the look: error correction, style, colours, margin and a logo. Warnings appear if the colours make the code hard to scan.

3. Press Download PNG or SVG, or copy the image straight into a document or chat. Choose 2048 px or 4096 px for print, or use the SVG, which stays sharp at any size.

4. To read a code, drop an image onto Read a QR code from an image or paste a screenshot with Ctrl + V. A Wi-Fi code shows the network name and password; Edit in generator loads any code into the form so you can change it and make a new one.

Short links: develzone.org/qr, /wifiqr opens the Wi-Fi form and /qrread jumps to the reader. Pasting a web address into the search box on the home page offers a QR code for it.

Static codes – no expiry, no tracking

Many QR websites create dynamic codes: the code holds a short link to their server, which redirects to your address and counts the scans. When the subscription ends or the service closes, every printed code stops working. The codes made here are static – your link, Wi-Fi password or contact is stored in the pattern itself. They work forever, offline, and nobody sees who scans them. To change the content later, you print a new code.

What the formats look like

Phones recognise a few text formats and offer the matching action. The Encoded text box shows exactly what goes into the code:

• Wi-Fi – WIFI:T:WPA;S:MyNetwork;P:secret;; – the camera offers to join the network. Special characters such as ; and : in the name or password are escaped with a backslash automatically.

• Contact – a vCard 3.0 (BEGIN:VCARD …) that phones save to the address book in one tap.

• E-mail – mailto: with subject and message, SMS – SMSTO:number:message, phone – tel:, location – geo:lat,lon, which opens the map app.

Error correction and size

QR codes contain extra Reed–Solomon data so they still scan when part of the code is dirty, damaged or covered. Level L can restore about 7 % of the code, M 15 %, Q 25 % and H 30 %. Higher levels need more modules, so the code gets denser. M is a good default; a logo in the centre covers part of the code and needs H – the generator switches to it when you add one.

The version (1 to 40) is the grid size: version 1 is 21 × 21 modules, each version adds 4, up to 177 × 177. Shorter content gives a smaller version with bigger modules that scan from further away – a short link is better than a long one with tracking parameters. Keep the white margin (quiet zone) of 4 modules around the code: without it, scanners struggle to find the edge.

Design tips

• Use dark modules on a light background with strong contrast. Inverted (light on dark) codes are not read by every scanner.

• Test the final code with two or three different phones before printing – especially with a logo, custom colours or the dot style.

• For print, make the code at least about 2 × 2 cm, and bigger for posters seen from a distance.

Privacy

Codes are generated and images are decoded entirely in your browser – nothing you type or drop here is sent to a server. The Share button creates a link with the content and the look of your code, but it never includes a Wi-Fi password.

Interesting facts

• QR stands for Quick Response. The code was invented in 1994 by Denso Wave, a Toyota group company, to track car parts in factories. Denso Wave chose not to enforce its patent, which is a big reason the format spread everywhere. It is standardised as ISO/IEC 18004.

• The three large squares in the corners are finder patterns: they tell the scanner where the code is and how it is rotated, from any angle.

• The largest QR code (version 40, level L) holds 7,089 digits, 4,296 letters and digits, or 2,953 bytes of text.

• Each code is drawn with one of eight mask patterns, chosen to avoid large blocks of the same colour that would confuse a scanner.