Pick the right size
A code needs to be about 1/10 of the scanning distance: 2 cm across for a business card read at 20 cm, 10 cm on a poster read at 1 m, 50 cm on a sign read from 5 m. When in doubt, go bigger.
Keep the quiet zone
Leave white space around the code, at least 4 of its small squares wide. Don't let text or borders touch it.
Contrast matters
Dark code on a light background, always. Avoid light colours for the code, busy photos behind it and inverted (light-on-dark) codes: many phone cameras struggle with them. The designer warns you when contrast is too low.
Choose the file format
- PNG: screens, social media, office printers. Download at 1024 px or more.
- SVG / PDF / EPS (Pro): professional print. They're vector, so they stay sharp at any size. Send your printer the PDF.
Test before you print a thousand
Print one copy at the real size and scan it with two different phones (iPhone and Android), in the light where it will be used. Your short link never changes, so you can change the destination later without reprinting.
On the item
Add a short line next to the code saying what people get ("See our menu", "Save my contact"). Codes with a reason to scan get scanned more.