Curious Programmer

Emulating rendering options in Chrome DevTools

#103 | August 27, 2021 | Estimated 3 minute read

I wrote an article about Simulating mobile devices in Chrome way back in 2016. I decided to extend it with this article where I cover different rendering options that can be emulated from simple to extreme accessibility features.

Let's dive right in. Open the tools, go to more tools on the main shish-kebab menu icon and click on Rendering. A new bottom split tab should open which should have options that look like 👇

Rendering tab An example of the contents in the Rendering tab which is displayed after you click on More tools > Rendering

Scroll down to the Emulate CSS media type option and checkout the selectable options. Changing the media type will force the selected media type so that you can test between print and screen styles! This way you don't have to print preview each time.

👇 are examples of the media types in action

@media print {
  ...;
}

@media screen {
  ...;
}

While you're at it, you can read the complete guide to CSS media queries article from CSS-Tricks.

Light vs Dark

If you have light and dark themes on your site you are most likely determining which one to use by default based on OS/browser preference. This little override emulates the CSS media feature prefers-color-scheme which forces the media type based on your selection: light or dark.

Vestibular motion

Our vestibular system is key to controlling balance and eye movement. People with vestibular disorders have the option to remove or replace the types of motion-based animation that trigger discomfort which gets set in the prefers-reduced-motion browser preference.

/* Applies styles when Reduced Motion is enabled */
@media screen and (prefers-reduced-motion: reduce) {
}

Read an introduction to the Reduced Motion Media Query, an article from CSS-Tricks.

Read another article, this one is titled "New in Chrome 74: Prefers-reduced-motion media query", an article from LogRocket.

Supported colors

Test the approximate range of colors that are supported by the user agent and the output device. Read about the expanding gamut of color on the web, an article from CSS-Tricks.

Vision deficiencies

New to Chrome 83, the new Emulate vision deficiencies feature to gives a better idea of how people with different types of vision deficiencies experience your site.

  • Protanopia: the inability to perceive any red light.
  • Deuteranopia: the inability to perceive any green light.
  • Tritanopia: the inability to perceive any blue light.
  • Achromatopsia: the inability to perceive any color except for shades of grey (extremely rare).

Read about simulating color vision deficiencies, an article from Chrome Developers.

Summary

With just one tab, Chrome DevTools can help you emulate your web applications from simple to extreme accessibility features. Keep an eye out for new features.