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Browser and Screen Sizes - JavaScript API#


CSS offers powerful media queries that alter the layout depending on the screen sizes, including but not limited to changes between landscape and portrait mode on mobile devices.

The Ui/Screen module exposes a consistent interface to execute JavaScript code based on the same media queries that are available in the CSS code already. It features support for unmatching and executing code when a rule matches for the first time during the page lifecycle.

Supported Aliases#

You can pass in custom media queries, but it is strongly recommended to use the built-in media queries that match the same dimensions as your CSS.

Alias Media Query
screen-xs (max-width: 544px)
screen-sm (min-width: 545px) and (max-width: 768px)
screen-sm-down (max-width: 768px)
screen-sm-up (min-width: 545px)
screen-sm-md (min-width: 545px) and (max-width: 1024px)
screen-md (min-width: 769px) and (max-width: 1024px)
screen-md-down (max-width: 1024px)
screen-md-up (min-width: 769px)
screen-lg (min-width: 1025px)

on(query: string, callbacks: Object): string#

Registers a set of callback functions for the provided media query, the possible keys are match, unmatch and setup. The method returns a randomly generated UUIDv4 that is used to identify these callbacks and allows them to be removed via .remove().

remove(query: string, uuid: string)#

Removes all callbacks for a media query that match the UUIDv4 that was previously obtained from the call to .on().

is(query: string): boolean#

Tests if the provided media query currently matches and returns true on match.


Temporarily prevents the page from being scrolled, until .scrollEnable() is called.


Enables page scrolling again, unless another pending action has also prevented the page scrolling.


The Environment module uses a mixture of feature detection and user agent sniffing to determine the browser and platform. In general, its results have proven to be very accurate, but it should be taken with a grain of salt regardless. Especially the browser checks are designed to be your last resort, please use feature detection instead whenever it is possible!

Sometimes it may be necessary to alter the behavior of your code depending on the browser platform (e. g. mobile devices) or based on a specific browser in order to work-around some quirks.

browser(): string#

Attempts to detect browsers based on their technology and supported CSS vendor prefixes, and although somewhat reliable for major browsers, it is highly recommended to use feature detection instead.

Possible values: - chrome (includes Opera 15+ and Vivaldi) - firefox - safari - microsoft (Internet Explorer and Edge) - other (default)

platform(): string#

Attempts to detect the browser platform using user agent sniffing.

Possible values: - ios - android - windows (IE Mobile) - mobile (generic mobile device) - desktop (default)

Last update: 2021-01-08