QR Code and Barcode Color Contrast Checker
A colorful QR code or barcode only works when the bars are much darker than the background. Pick the color of the bars and the background to see the contrast ratio, the print contrast used for barcodes, and a separate check for red-light scanners, which see red as if it were white. That is why a red barcode on white often fails at a shop till while a phone reads it.
Apply the colors in the QR code styling tool, the bulk QR code generator or any barcode generator on the site. Dark bars on a light background is always the safest choice.
What the numbers mean
- Contrast ratio (1 to 21): the web accessibility measure. 4 or more is a good sign for phone cameras.
- Print contrast: how much less light the bars reflect than the background. Barcode standards ask for about 70% or more.
- Red scanner: the same calculation using only the red channel, as a red laser sees it. Blue and black bars score well; red, orange and yellow bars score badly.
- Inverted codes (light on dark) are read by many phones but not by all scanners. Test before you print.