Contrast Swatch

Image microservice for color contrast information

Usage

Contrast swatch images can be used in any place an image is rendered. The URL accepts a foreground and background color.

https://contrast.now.sh/cff/40f

HTML

<img src="https://contrast.now.sh/cff/07c" alt="color contrast indicator" />

Markdown

![color contrast indicator](https://contrast.now.sh/cff/07c)

React

You can wrap the image in a React component (or any templating engine) for generating documentation.

import React from 'react'

export default ({
  foreground,
  background,
  ...props
}) =>
  <img
    {...props}
    src={`https://contrast.now.sh/${foreground}/${background}`}
    alt='color contrast indicator'
  />

RGB

Compare two rgb values, or an rgb and a hex value:

https://contrast.now.sh/rgb(204,255,255)/40f

Customization

Use URL queries to customize the styles.

https://contrast.now.sh/cff/40f?width=256&height=96&fontSize=1.25

Pass/Fail Label

Font Size

Size

Width & Height

Custom Text

Font Weight

Radius

Options

Option	Description
size	Width & height in pixels
width	Width of image in pixels
height	Height of image in pixels (font size will scale based on height)
fontSize	Relative font size (default 1)
fontWeight	Font weight (default 1)
label	Show a pass/fail label based on the WCAG Criteria
radius	Border radius
baseline	Shift text baseline down
text	Render any custom text

Metadata

A JSON response with color contrast information can be fetched by adding the type=json query to the URL.

https://contrast.now.sh/cff/40f?type=json

Note: the returned JSON schema might change in a future version

Related

• Colorable
• Use Contrast

MIT License