The quick brown fox jumps over the lazy dog
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Text Size

px

Styles
Permalink

Who can use this color combination?

Contrast Ratio

8.41:1

WCAG Grading

AAA

~Population
Vision Type
Simulation

68

%

Regular Vision (Trichromatic)

AAA

Can distinguish all three primary color, little to no blurriness

Text

1.3

%

Protanomaly

AAA

Trouble distinguishing reds

Text

1.5

%

Protanopia

AAA

Red blind - Can’t see reds at all

Text

5.3

%

Deuteranomaly

AAA

Trouble distinguishing greens

Text

1.2

%

Deuteranopia

AAA

Green blind - Can’t see greens at all

Text

0.02

%

Tritanomaly

AAA

Trouble distinguishing blues

Text

<0.03

%

Tritanopia

AAA

Blue blind - Can’t see blues at all

Text

<0.1

%

Achromatomaly

AAA

Partial color blindness, sees the absence of most colors

Text

<0.1

%

Achromatopsia

AAA

Complete color blindness, can only see shades

Text

33

%

Cataracts

AA

Clouding of the lens in the eye that affects vision

Text

2

%

Glaucoma

AAA

Slight vision loss

Text

31

%

Low Vision

AA

Decreased and/or blurry vision (not fixable by usual means such as glasses)

Text
Situational Vision Events
Simulation

Direct Sunlight

AA

Simulating what direct sunlight on a phone/screen would be

Text

Night Shift Mode

AAA

Simulating what would be seen on phones/screens with night mode on

Text

What is whocanuse.com?

It's a tool that brings attention and understanding to how color contrast can affect different people with visual impairments.

The Web Content Accessibility Guidelines (WCAG) covers a wide range of recommendations for making Web content more accessible. Just a tiny part of making the web more accessible is accommodating for those with a form of blindness or low vision.

The standard grading system is a great start, but I thought I'd try to humanize the people who are affected by the different grades.

Where did you get the info from?

The percentages are sourced from both colour-blindness.com and Vision Australia. P.S. You're both the best, thankyou ✌️

Your maths is off, it doesn't add up to 100%...?

Good eyes! (haha) The population data provided are estimates for individual impairments, and don't cover the vast amount of visual impairments in the world. This is to give you not just an understanding of how color contrast affects different people but also who it can affect.

I'm fascinated by how this works, can you tell me more?

Of course! There's a few stages to get to this point. First we figure out the contrast between two HEX values. For this we're using a plugin called Chrome.js - this does the heavy lifting for us. Once we have the ratio (and using font size and font weight) we can apply a grade to that specific color combo.

For the color blindness options we're using another plugin aptly called Color-blind that converts our HEX codes in to ones that would be seen by people with the different impairments, then we can apply our same process to obtain the color ratios and determine their grade.

For cataracts, glaucoma, low vision, and the situational events I've personally created simulations to help identify their rating.

What does a failing grade mean?

The grading uses a combination of color contrast, text size and text weight. A fail simply means that the color combination offers some visual strain to the person seeing it and should be avoided if possible.

Can I help contribute?

Absolutely! Feel free to fork the repo and submit a PR with any helpful additions or changes.

v1.0.0

Created & maintained byCorey@CoreyGinnivan