viewstat is a frontend-only JavaScript library that provides various tools to interact with CSS media queries and the viewport. It's features include:

• Polyfills for matchMedia and requestAnimationFrame.
• Screen/Viewport information, such as reliable width, height and devicePixelRatio detection as well as screen parameters like refresh rate and color depth.
• Media query tools to check support for individual rules, units and to determine the current values of media queries such as width and resolution.

• Chome 10 (tested)
• Edge 12
• Firefox 3.5 (tested)
• Opera 10
• IE 9 (tested)

Install the package using npm or yarn:

npm i viewstat@latest

yarn add viewstat@latest

To import from JavaScript:

// import the package as a bundle
import * as viewstat from "viewstat";

console.log(viewstat.VERSION);

Types and UMD exports are also available.

Although not recommended, the library can also be loaded directly into a web page via a CDN link:

<script type="text/javascript" src="https://unpkg.com/viewstat@latest/build/viewstat.umd.min.cjs" defer></script>

Note that this library must be loaded after the body element.

Get the current screen's refresh rate:

import { screen } from "viewstat";

const refreshRate = await screen.getRefreshRate();

Test support for the dppx unit in resolution media queries:

import { media } from "viewstat";

const supportsResolutionWithDPPX = media.supportsRangedMediaUnit("resolution", "dppx");

Check compatibility of requestAnimationFrame

import { getCompatInfo } from "viewstat";

const { name, supported } = getCompatInfo("requestAnimationFrame");
// e.g.
// supported: true
// name: "webkitRequestAnimationFrame"

Documentation is available here. Alternatively, it can be built directly from source.

Contributing to this project is strongly encouraged as I currently have little time to continue active development.

Development on this project requires Git and npm. Download the repository and install the dependencies:

git clone https://github.com/solarunes/viewstat.js viewstat
cd viewstat
npm install

Run a local development server. This will provide a local build in the dev directoy. HMR and live reload are supported by default.

npm run dev

More information and contributing guidelines are available on GitHub