Choosing the right type
URL codes are the most common and the most flexible: a scan opens the page in the browser. If the destination might change later, point the code at a short link you control so you can redirect it without reprinting. WiFi codes save guests from typing passwords and are ideal for cafes, rentals and offices; they work natively on iOS and Android cameras. Email, phone and SMS codes pre-fill the right app so the person only has to tap send or call. SMS codes with a keyword are widely used for text-message opt-ins: a code that encodes "JOIN" to your number lets someone subscribe in one tap, which pairs well with the opt-in disclosure generator for the consent language next to it.
Error correction: how much damage a code can take
QR codes include redundant data so they still scan when partly obscured or damaged. The four levels recover roughly 7%, 15%, 25% and 30% of the code. Higher correction means a denser grid, which needs more space or a closer scan. Medium (15%) is the right default for screens and clean prints. Use Quartile or High for codes that will be printed small, placed outdoors, or have a logo overlaid in the middle. Keep the encoded text short in those cases, because long URLs plus high correction produce very dense codes.
Colours, contrast and the quiet zone
Scanners look for dark modules on a light background. The generator checks the contrast between your two colours and warns when it falls below 3:1 or when the foreground is lighter than the background, both of which cause scan failures on some phones. Brand colours usually work fine for the foreground as long as they are dark enough; a navy or deep violet on white scans as well as black does. Avoid light foregrounds, patterned backgrounds and gradients.
The margin, also called the quiet zone, is the blank border around the code. The specification recommends four modules; the default here is two, which works on screens and most prints. If your code is going on a busy background or near other graphics, increase the margin to four so the scanner can find the edges.
PNG or SVG?
Download the PNG for websites, slides, documents and anywhere the code is shown at a fixed size. Choose a size at least as large as it will be displayed; 512 pixels is plenty for most uses. Download the SVG for anything that will be printed or resized: business cards, posters, menus, packaging and vehicle graphics. An SVG is vector, so it stays perfectly sharp at any size and designers can place it directly in their layout software.
Testing before you print
- Scan the preview with at least two phones, one iPhone and one Android, using the built-in camera app.
- Print a test page at the real size and scan it from the distance people will actually use. As a rule of thumb, the code should be at least one tenth of the scanning distance wide.
- If the code sits on a dark surface, invert the colours only if you have tested that it scans, or better, put it on a white label.
- Check the destination on a phone, not just a desktop, since that is how almost everyone who scans will see it.
Everything on this page runs in your browser: the text you enter, including WiFi passwords, is encoded locally and never sent to a server. If you use the Share button, the inputs are placed in the link, so do not share a link that contains a WiFi password with people who should not have it.