QR Code Size Guide

How big should a QR code be? A practical look at the relationship between print size, scan distance and reliability.

Size follows scan distance

The key rule of thumb: the further away people scan from, the bigger the code must be. A widely used guideline is a 10:1 ratio — the scan distance should be no more than about ten times the width of the code. A 2 cm code suits arm's-length scanning; a billboard needs a code many centimetres wide.

On-screen sizing

For codes shown on a screen, make sure they're displayed crisply and large enough that a second phone can capture them. Avoid scaling a small raster image up, which blurs the modules.

Print sizing

For print, don't go below roughly 2 cm (0.8 in) square for close-range scanning, and scale up for posters and signage. Use vector SVG so the code stays sharp at any size (see the printing guide).

Data density matters too

More data means more modules, and more modules mean each module is smaller at a given print size. If you must encode a lot, either enlarge the code or shorten the data. Our generators warn you when content is getting dense.

Quiet zone

Always keep the empty margin around the code — typically four modules wide. It doesn't count toward the "readable" area but it's essential for reliable scanning.

Always test

No formula guarantees a scan in every environment. Print a proof at the final size, on the final material, and test it with several phones before you commit.