Lazyload images, iframes or any src* element until they are visible in the viewport.
npm install lazyloadjs --save
See more examples.
<!DOCTYPE html>
<html>
<head>
<title>lazyload</title>
</head>
<body>
<script src="lazyload.min.js"></script>
<!-- A lot of content -->
<!-- A lot of content -->
<img
data-src="real/image/src.jpg"
src="data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw=="
onload="lzld(this)">
</body>
</html>
Make sure your webpage is in standards mode.
Viewport computing is badly handled by browsers when in quirksmode.
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.
lazyloadjs
is an npm module and is compatible with browserify.
global.myLazyload = require('lazyloadjs')();
<img
data-src="real/image/src.jpg"
src="data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw=="
onload="myLazyload(this)">
Per default, lazyloadjs
exposes the lzld
instance on the global
object. So that in most cases, you just need to require it in your webpage.
opts
is an object with these defaults:
{
container: document.body,
offset: 333,
src: 'data-src' // or function(elt) { return customSrc }
}
opts.container
is the referencing container, it's the viewport, defaults to document.body
opts.offset
is a length in pixels used to compute when an element will
soon be visible. So that you load it just before it becomes visible.
src
is the attribute name storing the real src of the element to load.
src
can also be a function
, so that you can have your custom src
computing algorithm.
You can use it to lazyload High DPI/retina images.
npm run examples
Launch the dev server:
npm run dev
Browse to https://localhost:8080/__zuul.
We provide a pre-built version of lazyloadjs
in build/lazyload.min.js
.
But you can build your own:
npm run build
You get the build in build/lazyload.min.js
.
Please consider using browserify.
Tens of millions of pageviews are served each month using this project:
- fasterize.com
lazyload
was first developed at fasterize (WPO solution) - lemonde.fr
- pluzz.francetv.fr
- pcinpact.com
- elpais.com
- playtv.fr
- voyages-sncf.com
- rue89.com
- flipkart.com
- clubic.com
- achetezfacile.com
- mapado.com
- decitre.fr
- base-orb.fr
- kokoroe.co
.. And many unlisted websites, add yours!
Also see LICENCE.fasterize
(The MIT Licence)
Copyright (c) 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.