Dark designs are everywhere and a black QR code on them looks like a hole. The tempting fix is to invert the code. Sometimes that is fine. Often it is a gamble you did not need to take.
What the standard says
ISO/IEC 18004 defines a QR code as dark modules on a light background. Decoders are free to also try the reverse, and good ones do, but nothing requires it. So an inverted code works on any scanner that tries both polarities and fails on any that does not.
Who reads them and who does not
| Scanner | Inverted codes |
|---|---|
| iPhone Camera (iOS 11 and later) | Yes |
| Recent Android camera apps and Google Lens | Usually |
| Older third-party scanner apps | Often not |
| Point-of-sale and access-control scanners | Frequently not |
| Web-based decoders | Varies |
When inverted is acceptable
- On a screen, for an audience using recent phones: an app onboarding screen, a conference slide, a TV.
- When you have tested with the actual scanner that will be used.
- When a fallback exists, such as the URL printed alongside.
Do this
An inverted code on a slide at a tech conference, with the short URL printed beneath it.
Not this
An inverted code on a bus-shelter poster read by whoever walks past with whatever phone they own.
The safer alternative
Put a normal code on a white tile, then place the tile on the dark design. Round the corners of the tile, give the code its quiet zone inside it, and the design stays dark while the code stays standard.
Do this
White rounded tile, black code inside with a four-module margin, on the dark background.
Not this
White modules straight onto the dark background because the tile 'broke the look'.
Common mistake
Inverting the code and also using a dark brand colour for the background that is not quite dark enough. Now it is both inverted and low contrast. Check the ratio either way with the contrast checker.
Try it in QR Studio
QR Studio warns when you pick an inverted pair and offers the tile layout as a one-tap alternative.
Checklist
- Decided whether the audience’s scanners are known
- If inverted, tested with the oldest scanner likely to be used
- Contrast ratio still 4.5 to 1 or better
- URL or fallback printed nearby for public placements
- Preferred the white tile where any doubt remained
Try it yourself
Upload your inverted artwork. The tester tries both polarities and tells you whether it only reads one way round.