An ultra-light jQuery plugin that tells you if the element is in the viewport, but with a twist. Did you say demo?

Current version: 1.1.0

• Added support for :in-viewport selector as per joeframbach's suggestion.

• Download either isInViewport.js or isInViewport.min.js ( or bower install isInViewport )
• Add it after you include jQuery
• You're ready to go!

As of version 1.1.0, the :in-viewport selector is preferred way of using the plugin.
Syntax is as below:

$( 'selector:in-viewport' )

When used as a selector it returns all the elements that match. Since it returns the element(s) it can thus be chained with other jQuery methods.

$( 'div:in-viewport' ).css( 'background-color', 'red' );

This will set the background-color as red for all divs that are in the viewport.

$( selector ).isInViewport()

This returns true if the element is in the viewport and false otherwise.

As of version 1.1.0, you can use the :in-viewport selector with the tolerance passed as a parameter to the selector. This removes the need to loop over a collection of elements and to test them all separately using .isInViewport() method. The syntax is given below:

$( 'selector:in-viewport( tolerance )' )

$( 'div:in-viewport( 100 )' ).css( 'background-color', 'red' );

This will set the background-color as red for all divs that are in the viewport with a tolerance of 100px.

With the advanced usage it becomes very easy to build things like menus with items that get auto-highlighted based on which section you are on, transition effects when an element comes into the viewport, etc.

• Note that the :in-viewport selector does not support the debug parameter.
• If you need to use debug then use the method call syntax:
  isInViewport( {"tolerance": 100, "debug": true} )

$( selector ).isInViewport( {"tolerance" :100, "debug": true} )

.isInViewport() takes two options:

• tolerance specfies the upper limit in pixels of when the element is deemed in viewport.
  It defaults to 0.
• debug enables logging to the console.
  It defaults to false.

See the examples in the examples directory for more clarity.

Chrome, Firefox 3.0+, IE6+, Safari 4.0+, Opera 10.0+

• :in-viewport selector does support chaining.
• .isInViewport() doesn't support chaining as it returns a boolean value.
• To use with IE < 9 use jQuery <= 1.7.0