Check your QR code colours
Pick a code colour and a background. You see the contrast ratio, whether phones will read it, and the nearest colours that fix it if they won't.
Your codes are made in your browser. Nothing you type is sent anywhere.
Contrast
6.7 : 1
Enough to scan in good light, but close to the limit. Print a test and scan it where the code will hang.
Black on white is 21 : 1. Codes need at least 4 : 1; aim for 7 : 1 or more for print.
Try instead
Version 2 · 25×25 modules · Level M · 19 bytes
Colours and error correction
How to check your QR code colours
- 01Choose the code colour and the background, or type their hex values.
- 02Read the contrast ratio and what it means for scanning.
- 03If it's too low, select a suggested colour to apply it.
- 04Select Test scan, then download the code in your colours.
Questions
How much contrast does a QR code need?
At least 4 to 1 between the code and the background, and 7 to 1 or more is safer for print. Black on white is 21 to 1. Below 4 to 1, many phones fail to separate the squares from the background.
Can I use brand colours?
Yes, if the code colour is much darker than the background. Dark blues, greens, purples, and reds usually work on white. Yellow, orange, light grey, and pastels usually don't. The suggestions keep your colour's hue and only make it darker or lighter.
Can a QR code be light on a dark background?
Many newer phones read inverted codes, but some phones and older scanner apps can't. For anything printed in quantity, keep the code darker than its background.
How is the ratio worked out?
With the same relative-brightness formula used for text accessibility (WCAG). It compares how bright each colour looks to the eye, not their hue, which is also what matters to a camera.
Why does Test scan pass but you still warn me?
The test reads a perfect digital image. Phone cameras see glare, shadows, and ink spread, so faint colours that read on screen can still fail in print.
Do you see what I type?
No. Your codes are made in your browser. Nothing you type is sent anywhere.
Related tools
- Will it scan?Pass or fail for a code printed small, blurred, or faded.
- Custom QR codeDot shapes, corner shapes, and gradients, each checked to scan.
- Transparent QR codePNG and SVG with no background, checked on your surface.
- QR code with logoYour logo in the centre, checked to scan after it goes in.
- Size calculatorSmallest print size from scan distance and your real content.
QR Code is a registered trademark of DENSO WAVE INCORPORATED. Codes are read back with ZXing-C++ and zxing-wasm (licences).