<link href='https://fonts.googleapis.com/css?family=Open+Sans' rel='stylesheet' type='text/css'>

<div class="section parallax-window" data-parallax="scroll" data-image-src="http://dummy-images.com/people/dummy-1600x900-WeekiWacheeSpring.jpg">
  <h1>SECTION ONE</h1>
  <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin urna tellus, auctor a fermentum id, dignissim vel sem. Interdum et malesuada fames ac ante ipsum primis in faucibus. Quisque imperdiet dolor mattis rutrum pellentesque. Ut lorem tellus, condimentum non gravida sit amet, maximus sed est. Vestibulum sed metus dolor. Proin laoreet velit vel felis eleifend molestie sit amet in felis. Donec fermentum eget urna id egestas.</p>
</div>

<div class="section">
  <h1>SECTION TWO</h1>
  <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin urna tellus, auctor a fermentum id, dignissim vel sem. Interdum et malesuada fames ac ante ipsum primis in faucibus. Quisque imperdiet dolor mattis rutrum pellentesque. Ut lorem tellus, condimentum non gravida sit amet, maximus sed est. Vestibulum sed metus dolor. Proin laoreet velit vel felis eleifend molestie sit amet in felis. Donec fermentum eget urna id egestas.</p>
</div>

<div class="section parallax-window" data-parallax="scroll" data-image-src="http://dummy-images.com/people/dummy-1600x900-SarahVaughan.jpg">
  <h1>SECTION THREE</h1>
  <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin urna tellus, auctor a fermentum id, dignissim vel sem. Interdum et malesuada fames ac ante ipsum primis in faucibus. Quisque imperdiet dolor mattis rutrum pellentesque. Ut lorem tellus, condimentum non gravida sit amet, maximus sed est. Vestibulum sed metus dolor. Proin laoreet velit vel felis eleifend molestie sit amet in felis. Donec fermentum eget urna id egestas.</p>
</div>

<div class="section">
  <h1>SECTION FOUR</h1>
  <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin urna tellus, auctor a fermentum id, dignissim vel sem. Interdum et malesuada fames ac ante ipsum primis in faucibus. Quisque imperdiet dolor mattis rutrum pellentesque. Ut lorem tellus, condimentum non gravida sit amet, maximus sed est. Vestibulum sed metus dolor. Proin laoreet velit vel felis eleifend molestie sit amet in felis. Donec fermentum eget urna id egestas.</p>
</div>

<div class="section parallax-window" data-parallax="scroll" data-image-src="http://dummy-images.com/buildings/dummy-1600x900-NYSkyline.jpg">
  <h1>SECTION FIVE</h1>
  <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin urna tellus, auctor a fermentum id, dignissim vel sem. Interdum et malesuada fames ac ante ipsum primis in faucibus. Quisque imperdiet dolor mattis rutrum pellentesque. Ut lorem tellus, condimentum non gravida sit amet, maximus sed est. Vestibulum sed metus dolor. Proin laoreet velit vel felis eleifend molestie sit amet in felis. Donec fermentum eget urna id egestas.</p>
</div>
/* Demo Styles */
body {
  margin: 0 0;
  padding: 0 0;
  font-family: 'Open Sans', sans-serif;
  background: #000;
}
.section {
  padding: 200px 20px;
  text-align: center;
  color: #fff;
}

.section-two {
  padding: 200px 20px;
  text-align: center;
  color: #fff;
}
p {
  max-width: 600px;
  padding: 0 30px;
  margin: 0 auto;
  line-height: 1.6em;
}
/*!
 * parallax.js v1.4.2 (https://pixelcog.github.io/parallax.js/)
 * @copyright 2016 PixelCog, Inc.
 * @license MIT (https://github.com/pixelcog/parallax.js/blob/master/LICENSE)
 */

;(function ( $, window, document, undefined ) {

  // Polyfill for requestAnimationFrame
  // via: https://gist.github.com/paulirish/1579671

  (function() {
    var lastTime = 0;
    var vendors = ['ms', 'moz', 'webkit', 'o'];
    for(var x = 0; x < vendors.length && !window.requestAnimationFrame; ++x) {
      window.requestAnimationFrame = window[vendors[x]+'RequestAnimationFrame'];
      window.cancelAnimationFrame = window[vendors[x]+'CancelAnimationFrame']
        || window[vendors[x]+'CancelRequestAnimationFrame'];
    }

    if (!window.requestAnimationFrame)
      window.requestAnimationFrame = function(callback) {
        var currTime = new Date().getTime();
        var timeToCall = Math.max(0, 16 - (currTime - lastTime));
        var id = window.setTimeout(function() { callback(currTime + timeToCall); },
          timeToCall);
        lastTime = currTime + timeToCall;
        return id;
      };

    if (!window.cancelAnimationFrame)
      window.cancelAnimationFrame = function(id) {
        clearTimeout(id);
      };
  }());


  // Parallax Constructor

  function Parallax(element, options) {
    var self = this;

    if (typeof options == 'object') {
      delete options.refresh;
      delete options.render;
      $.extend(this, options);
    }

    this.$element = $(element);

    if (!this.imageSrc && this.$element.is('img')) {
      this.imageSrc = this.$element.attr('src');
    }

    var positions = (this.position + '').toLowerCase().match(/\S+/g) || [];

    if (positions.length < 1) {
      positions.push('center');
    }
    if (positions.length == 1) {
      positions.push(positions[0]);
    }

    if (positions[0] == 'top' || positions[0] == 'bottom' || positions[1] == 'left' || positions[1] == 'right') {
      positions = [positions[1], positions[0]];
    }

    if (this.positionX != undefined) positions[0] = this.positionX.toLowerCase();
    if (this.positionY != undefined) positions[1] = this.positionY.toLowerCase();

    self.positionX = positions[0];
    self.positionY = positions[1];

    if (this.positionX != 'left' && this.positionX != 'right') {
      if (isNaN(parseInt(this.positionX))) {
        this.positionX = 'center';
      } else {
        this.positionX = parseInt(this.positionX);
      }
    }

    if (this.positionY != 'top' && this.positionY != 'bottom') {
      if (isNaN(parseInt(this.positionY))) {
        this.positionY = 'center';
      } else {
        this.positionY = parseInt(this.positionY);
      }
    }

    this.position =
      this.positionX + (isNaN(this.positionX)? '' : 'px') + ' ' +
      this.positionY + (isNaN(this.positionY)? '' : 'px');

    if (navigator.userAgent.match(/(iPod|iPhone|iPad)/)) {
      if (this.imageSrc && this.iosFix && !this.$element.is('img')) {
        this.$element.css({
          backgroundImage: 'url(' + this.imageSrc + ')',
          backgroundSize: 'cover',
          backgroundPosition: this.position
        });
      }
      return this;
    }

    if (navigator.userAgent.match(/(Android)/)) {
      if (this.imageSrc && this.androidFix && !this.$element.is('img')) {
        this.$element.css({
          backgroundImage: 'url(' + this.imageSrc + ')',
          backgroundSize: 'cover',
          backgroundPosition: this.position
        });
      }
      return this;
    }

    this.$mirror = $('<div />').prependTo('body');

    var slider = this.$element.find('>.parallax-slider');
    var sliderExisted = false;

    if (slider.length == 0)
      this.$slider = $('<img />').prependTo(this.$mirror);
    else {
      this.$slider = slider.prependTo(this.$mirror)
      sliderExisted = true;
    }

    this.$mirror.addClass('parallax-mirror').css({
      visibility: 'hidden',
      zIndex: this.zIndex,
      position: 'fixed',
      top: 0,
      left: 0,
      overflow: 'hidden'
    });

    this.$slider.addClass('parallax-slider').one('load', function() {
      if (!self.naturalHeight || !self.naturalWidth) {
        self.naturalHeight = this.naturalHeight || this.height || 1;
        self.naturalWidth  = this.naturalWidth  || this.width  || 1;
      }
      self.aspectRatio = self.naturalWidth / self.naturalHeight;

      Parallax.isSetup || Parallax.setup();
      Parallax.sliders.push(self);
      Parallax.isFresh = false;
      Parallax.requestRender();
    });

    if (!sliderExisted)
      this.$slider[0].src = this.imageSrc;

    if (this.naturalHeight && this.naturalWidth || this.$slider[0].complete || slider.length > 0) {
      this.$slider.trigger('load');
    }

  };


  // Parallax Instance Methods

  $.extend(Parallax.prototype, {
    speed:    0.4,
    bleed:    0,
    zIndex:   -100,
    iosFix:   true,
    androidFix: true,
    position: 'center',
    overScrollFix: false,

    refresh: function() {
      this.boxWidth        = this.$element.outerWidth();
      this.boxHeight       = this.$element.outerHeight() + this.bleed * 2;
      this.boxOffsetTop    = this.$element.offset().top - this.bleed;
      this.boxOffsetLeft   = this.$element.offset().left;
      this.boxOffsetBottom = this.boxOffsetTop + this.boxHeight;

      var winHeight = Parallax.winHeight;
      var docHeight = Parallax.docHeight;
      var maxOffset = Math.min(this.boxOffsetTop, docHeight - winHeight);
      var minOffset = Math.max(this.boxOffsetTop + this.boxHeight - winHeight, 0);
      var imageHeightMin = this.boxHeight + (maxOffset - minOffset) * (1 - this.speed) | 0;
      var imageOffsetMin = (this.boxOffsetTop - maxOffset) * (1 - this.speed) | 0;

      if (imageHeightMin * this.aspectRatio >= this.boxWidth) {
        this.imageWidth    = imageHeightMin * this.aspectRatio | 0;
        this.imageHeight   = imageHeightMin;
        this.offsetBaseTop = imageOffsetMin;

        var margin = this.imageWidth - this.boxWidth;

        if (this.positionX == 'left') {
          this.offsetLeft = 0;
        } else if (this.positionX == 'right') {
          this.offsetLeft = - margin;
        } else if (!isNaN(this.positionX)) {
          this.offsetLeft = Math.max(this.positionX, - margin);
        } else {
          this.offsetLeft = - margin / 2 | 0;
        }
      } else {
        this.imageWidth    = this.boxWidth;
        this.imageHeight   = this.boxWidth / this.aspectRatio | 0;
        this.offsetLeft    = 0;

        var margin = this.imageHeight - imageHeightMin;

        if (this.positionY == 'top') {
          this.offsetBaseTop = imageOffsetMin;
        } else if (this.positionY == 'bottom') {
          this.offsetBaseTop = imageOffsetMin - margin;
        } else if (!isNaN(this.positionY)) {
          this.offsetBaseTop = imageOffsetMin + Math.max(this.positionY, - margin);
        } else {
          this.offsetBaseTop = imageOffsetMin - margin / 2 | 0;
        }
      }
    },

    render: function() {
      var scrollTop    = Parallax.scrollTop;
      var scrollLeft   = Parallax.scrollLeft;
      var overScroll   = this.overScrollFix ? Parallax.overScroll : 0;
      var scrollBottom = scrollTop + Parallax.winHeight;

      if (this.boxOffsetBottom > scrollTop && this.boxOffsetTop <= scrollBottom) {
        this.visibility = 'visible';
        this.mirrorTop = this.boxOffsetTop  - scrollTop;
        this.mirrorLeft = this.boxOffsetLeft - scrollLeft;
        this.offsetTop = this.offsetBaseTop - this.mirrorTop * (1 - this.speed);
      } else {
        this.visibility = 'hidden';
      }

      this.$mirror.css({
        transform: 'translate3d(0px, 0px, 0px)',
        visibility: this.visibility,
        top: this.mirrorTop - overScroll,
        left: this.mirrorLeft,
        height: this.boxHeight,
        width: this.boxWidth
      });

      this.$slider.css({
        transform: 'translate3d(0px, 0px, 0px)',
        position: 'absolute',
        top: this.offsetTop,
        left: this.offsetLeft,
        height: this.imageHeight,
        width: this.imageWidth,
        maxWidth: 'none'
      });
    }
  });


  // Parallax Static Methods

  $.extend(Parallax, {
    scrollTop:    0,
    scrollLeft:   0,
    winHeight:    0,
    winWidth:     0,
    docHeight:    1 << 30,
    docWidth:     1 << 30,
    sliders:      [],
    isReady:      false,
    isFresh:      false,
    isBusy:       false,

    setup: function() {
      if (this.isReady) return;

      var $doc = $(document), $win = $(window);

      var loadDimensions = function() {
        Parallax.winHeight = $win.height();
        Parallax.winWidth  = $win.width();
        Parallax.docHeight = $doc.height();
        Parallax.docWidth  = $doc.width();
      };

      var loadScrollPosition = function() {
        var winScrollTop  = $win.scrollTop();
        var scrollTopMax  = Parallax.docHeight - Parallax.winHeight;
        var scrollLeftMax = Parallax.docWidth  - Parallax.winWidth;
        Parallax.scrollTop  = Math.max(0, Math.min(scrollTopMax,  winScrollTop));
        Parallax.scrollLeft = Math.max(0, Math.min(scrollLeftMax, $win.scrollLeft()));
        Parallax.overScroll = Math.max(winScrollTop - scrollTopMax, Math.min(winScrollTop, 0));
      };

      $win.on('resize.px.parallax load.px.parallax', function() {
          loadDimensions();
          Parallax.isFresh = false;
          Parallax.requestRender();
        })
        .on('scroll.px.parallax load.px.parallax', function() {
          loadScrollPosition();
          Parallax.requestRender();
        });

      loadDimensions();
      loadScrollPosition();

      this.isReady = true;
    },

    configure: function(options) {
      if (typeof options == 'object') {
        delete options.refresh;
        delete options.render;
        $.extend(this.prototype, options);
      }
    },

    refresh: function() {
      $.each(this.sliders, function(){ this.refresh() });
      this.isFresh = true;
    },

    render: function() {
      this.isFresh || this.refresh();
      $.each(this.sliders, function(){ this.render() });
    },

    requestRender: function() {
      var self = this;

      if (!this.isBusy) {
        this.isBusy = true;
        window.requestAnimationFrame(function() {
          self.render();
          self.isBusy = false;
        });
      }
    },
    destroy: function(el){
      var i,
          parallaxElement = $(el).data('px.parallax');
      parallaxElement.$mirror.remove();
      for(i=0; i < this.sliders.length; i+=1){
        if(this.sliders[i] == parallaxElement){
          this.sliders.splice(i, 1);
        }
      }
      $(el).data('px.parallax', false);
      if(this.sliders.length === 0){
        $(window).off('scroll.px.parallax resize.px.parallax load.px.parallax');
        this.isReady = false;
        Parallax.isSetup = false;
      }
    }
  });


  // Parallax Plugin Definition

  function Plugin(option) {
    return this.each(function () {
      var $this = $(this);
      var options = typeof option == 'object' && option;

      if (this == window || this == document || $this.is('body')) {
        Parallax.configure(options);
      }
      else if (!$this.data('px.parallax')) {
        options = $.extend({}, $this.data(), options);
        $this.data('px.parallax', new Parallax(this, options));
      }
      else if (typeof option == 'object')
      {
        $.extend($this.data('px.parallax'), options);
      }
      if (typeof option == 'string') {
        if(option == 'destroy'){
            Parallax['destroy'](this);
        }else{
          Parallax[option]();
        }
      }
    })
  };

  var old = $.fn.parallax;

  $.fn.parallax             = Plugin;
  $.fn.parallax.Constructor = Parallax;


  // Parallax No Conflict

  $.fn.parallax.noConflict = function () {
    $.fn.parallax = old;
    return this;
  };


  // Parallax Data-API

  $(document).on('ready.px.parallax.data-api', function () {
    $('[data-parallax="scroll"]').parallax();
  });

}(jQuery, window, document));

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

  1. //cdnjs.cloudflare.com/ajax/libs/jquery/2.2.2/jquery.min.js