QR Codewith Logo

QR codes carry spare data, called error correction, so they can still be read when part of the code is dirty or torn. A logo in the middle is just a planned bit of damage: the scanner rebuilds the covered squares from the spare data.

This tool always uses the highest level, H, which can rebuild about 30% of the code. The logo's box is capped at 30% of the width, which is about 9% of the area, so there's plenty of room left for a scuff or a bad print.

Most logo codes that don't scan break one of these rules:

• The logo covers the three big corner squares. Scanners use them to find the code, so the logo must sit in the middle only.
• The logo is too big. Keep it to about a fifth of the width unless you've tested it on several phones.
• Low contrast. A pale code colour or a busy background hides the squares, whatever the logo.
• No quiet zone. Keep at least a 2-module blank border around the code.
• A long link. More characters mean smaller squares, and small squares break first. Shorten the link before you add a logo.

A simple, square mark works best: an icon, a monogram or the first letter of your brand. A wide wordmark shrinks to fit the box and becomes hard to read.

Use a PNG with a transparent background, or an SVG. Leave 'Clear space behind the logo' on, so the squares under the logo are removed and it sits on a clean backdrop. Turn it off only for a transparent logo you want floating over the code.

Scan the preview with at least two phones, an iPhone and an Android if you can, from the distance people will actually use. Try it in dim light too.

Then print one copy at the real size and scan that. A code that works on screen can fail on glossy paper, a curved cup or a dark wall. If any test is slow, make the logo a little smaller or the code a little bigger.