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The wp-webp Plugin gives your site the ability to show images in WebP format using WebPJS by Dominik Homberger 
It simply adds the javascript as describe at http://webpjs.appspot.com/ to your site. 
You can choose between adding to the header or the footer and you can choose if it’s added allways or just 
when the browser used does not support WebP itself.
Credits: 
 Thanks to Dominik Homberger who developed the grep WebPJS (http://webpjs.appspot.com/) 
 which is included in the subdir webpjs

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