Kilian Valkhof

Building tools that make developers awesome.

Detecting media query support in CSS and JavaScript

CSS & HTML, Javascript, Web, 13 July 2021

Recently I needed a way to detect support for a media query in CSS and Javascript. To detect if a browser supports a certain CSS feature, you can use @supports () { ... }, but that doesn’t work for media queries. In this article I’ll show you how you can detect support for media queries regardless of if they are turned on.

Increasing access to your website with “prefers-reduced-data”

Accessibility, 12 July 2021

The upcoming “prefers-reduced-data” media query will make your site more accessible in the “more people can now enter the building” meaning of accessibility. In this recording of my talk given at Shortstack conference you will learn strategies to start implementing this feature now and make your site available to even more people.

Fixing contrast issues, on your own site and elsewhere

Accessibility, 8 June 2021

Insufficient text contrast is the most common accessibility issue on websites today. According to the WebAIM Million report for 2021, 86.4% of home pages world wide have low contrast text. What’s worse, this number has been increasing the past three years.

Prescriptive software is better than descriptive software

Web, 5 April 2021

For a while now I’ve been telling people that I want Polypane to be prescriptive, not descriptive. In this article I want to expand on that and explain what I mean when I say “prescriptive”.

I’m speaking at Webdirections Hover!

CSS & HTML, 12 March 2021

April 30th I will be speaking at Webdirections Hover on a topic very dear to me: New and future media queries. Read on for more info on the conference, how to get tickets and a discount!

Polypane browser for responsive web development and design Hi, I'm Kilian. I make Polypane, the browser for responsive web development and design. If you're reading this site, that's probably interesting to you. Try it out!

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Go on a text adventure in Facebook Messenger.


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Drag-and-drop lossless compression of PNG and JPG images for web.

Messenger Demo Viewer

Demo your (bot) interactions on Messenger.