Lazyload images, iframes, divs, widgets untill they are visible in the viewport.
Battle tested against IE8+ Android Ch FF.
<!doctype html>
<script src="lazyload.min.js"></script>
<body>
<!-- You should not lazyload first images of your website -->
<img src="not/lazyloaded.jpg" />
<img
data-src="real/image/src.jpg"
src=data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==
/>
<iframe
data-src="yourpage.html"
src="about:blank"
onload=lzld(this)></iframe>
</body>If you do not want to use a data-uri as your src, you can also use the provided b.gif which is the tiniest gif ever.
On most websites, you better let the first top images not bound to lzld method. So that they shows really fast.
Here are the options and defaults. All parameters are optional.
var myLzld = lazyload({
container: document.body,
offset: 200,
src: 'data-src' // or function(elt) { return customSrc }
});- container: Which element to be used as the
viewport - offset: When watched element is
offsetpx near the viewport bounds, show it (horizontal, vertical) - src: Where to find the real src of your element, either in another attribute (data-src) or using a custom function
When giving a function to the src param, you can implement a custom src selector.
So you can handle resolution dependent images.
<!doctype html>
<script src="lazyload.min.js"></script>
<script>
var lazyHd = lazyload({ src: hidpi });
function hidpi(img) {
if(window.devicePixelRatio > 1) {
return img.getAttribute('data-src-hd');
}
}
</script>
<body>
<img
data-src-hd="images/src-hd.jpg"
src="images/src-desktop.jpg"
onload=lazyHd(this) />
</body>Here you go! You are now loading a standard desktop image and loading the hd version when needed. You could also load a blank image at start and choose either the desktop or hd version.
If your function does not returns anything special then the initial src= image will not be changed.
Open test/test.html or use a headless browser:
# you may need to install phantomjs manually if you are on osx or windows
npm install -g mocha-phantomjs phantomjs
npm testYou need package.json dependencies and grunt.
npm install
npm install -g grunt-cli
grunt watchStart an http-server in root dir:
npm install http-server -g
http-serverOpen test/test.html, code, test.
We use closure compiler.
CLOSURE_PATH="~/path/to/compiler.jar" gruntYou get a build/lazyload.min.js file.
compiler.jar is google closure compiler .jar location.
Millions of pageviews are served using this project:
- fasterize.com
lazyloadwas first developed at fasterize (WPO solution) - lemonde.fr
- pluzz.francetv.fr
- pcinpact.com
- elpais.com
- playtv.fr
- voyages-sncf.com
- rue89.com
Also see LICENCE.fasterize
(The MIT Licence)
Copyright (c) 2012-2013 Vincent Voyer
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.