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    Reveal CSS animation as you scroll down a page
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    WOW.js Build Status

    Reveal CSS animation as you scroll down a page. By default, you can use it to trigger animate.css animations. But you can easily change the settings to your favorite animation library.


    • Smaller than other JavaScript parallax plugins, like Scrollorama (they do fantastic things, but can be too heavy for simple needs)
    • Super simple to install, and works with animate.css, so if you already use it, that will be very fast to setup
    • Fast execution and lightweight code: the browser will like it ;-)
    • You can change the settings - see below

    Follow @mattdelac_ for updates as WOW evolves.





    Commercial license

    If you want to use WOW.js to develop commercial sites, themes, projects, and applications, the Commercial license is the appropriate license. With this option, your source code is kept proprietary. Purchase a WOW.js Commercial License at

    Open source license

    If you are creating an open source application under a license compatible with the GNU GPL license v3, you may use this project under the terms of the GPLv3.


    It just take seconds to install and use WOW.js! Read the documentation ➫



    • Bower
       bower install wowjs
    • NPM
       npm install wowjs

    Basic usage

    In order to hide all elements when they are supposed to be hidden. (Anti Flickering)

    • CSS .wow { visibility: hidden; }

    • HTML

      <section class="wow slideInLeft"></section>
      <section class="wow slideInRight"></section>
    • JavaScript
    new WOW().init();

    Advanced usage

    • HTML
      <section class="wow slideInLeft" data-wow-duration="2s" data-wow-delay="5s"></section>
      <section class="wow slideInRight" data-wow-offset="10"  data-wow-iteration="10"></section>
    • JavaScript
    var wow = new WOW(
        boxClass:     'wow',      // animated element css class (default is wow)
        animateClass: 'animated', // animation css class (default is animated)
        offset:       0,          // distance to the element when triggering the animation (default is 0)
        mobile:       true,       // trigger animations on mobile devices (default is true)
        live:         true,       // act on asynchronously loaded content (default is true)
        callback:     function(box) {
          // the callback is fired every time an animation is started
          // the argument that is passed in is the DOM node being animated
        scrollContainer: null // optional scroll container selector, otherwise use window

    Asynchronous content support

    In IE 10+, Chrome 18+ and Firefox 14+, animations will be automatically triggered for any DOM nodes you add after calling wow.init(). If you do not like that, you can disable this by setting live to false.

    If you want to support older browsers (e.g. IE9+), as a fallback, you can call the wow.sync() method after you have added new DOM elements to animate (but live should still be set to true). Calling wow.sync() has no side effects.


    You're more than welcome to contribute to this project. Please note: your code may be used as part of a commercial product if merged. Be clear about what license applies to your patch. The MIT license or public domain unlicense are permissive, and allow integration of your patch into this project as part of a commercial product.

    The library is written in CoffeeScript, please update file.

    We use grunt to compile and minify the library:

    Install needed libraries

    npm install

    Get the compilation running in the background

    grunt watch


    Bug tracker

    If you find a bug, please report it here on Github!


    Developed by Matt Delac,


    Thanks to everyone who has contributed to the project so far:

    Initiated and designed by Vincent Le Moign, @webalys

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