Francesco Sganga

Optimize images (jpg, png) in your WordPress site by converting them to .webp extension (it uses PHP GD library) 
WP Media Optimizer (.webp) only works with Firefox and Chrome (at this time).
— SAFARI NOW SUPPORTS .WEBP images —
Now with LAZY LOAD FEATURE!
IMPORTANT: WPMOWEBP works only in the frontend side of your website (e.g. not in wp-admin/)
ABOVE THE FOLD Feature is not really “for dummies” but with some tests you can really improve your PAGE SPEED RATE! Hope you can appreciate this feature.
USAGE
Simply install and activate it, and your images will be optimized.
You can send a Feature Request from the Plugin Settings Page. 
I hope you will use this form so I can add new features to this simple and wonderfurl plugin!
You can enable the new Lazy Load Feature by making a little donation to the author, you will receive a life time token for this feature and future improvements.
HOW IT WORKS
When anyone access to a WordPress page, plugin check for images already converted to .webp. 
If one or more images have not been already converted, the plugin converts them immediately. 
Converted images are stored in a subfolder of wp-content folder: wp-content/wpmowebp
TROUBLESHOOTING
If WordPress go out of memory try to add 
define(‘WP_MEMORY_LIMIT’, ‘256M’); 
to your wp-config.php
Enjoy your new WordPress Plugin.

WP Media Optimizer (.webp)

Automatically optimize images in your Wordpress site by converting them to .webp extension

Prateek Kathal

This is not the official plugin for TinyPNG. Please go to the following link for the official plugin – https://wordpress.org/plugins/tiny-compress-images/
This is a WordPress Plugin used to connect with the TinyPNG.com API and optimize/reduce the size of your PNG file on the go. Its fast and reliable.
Instructions on How to Use:
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Put in the correct email address and the TinyPNG API Key associated with it. (If you haven’t made one yet, you can visit this link to make one – https://tinypng.com/developers )
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Upload the PNG file using the uploader. As soon as the uploading finishes, the plugin will connect to the TinyPNG API and get you the Optimized image. (The files uploaded and optimized are saved in the TInyPNG folder in the main wordpress media folder. For eg – /wp-content/TinyPNG )
</li>
</ol>
Note :- Because of too much work and less of time, I am not able to work on this plugin much. I asure of you testing it in all WordPress Platforms, but any updates on its features wont be possible before July. Sorry for the inconvenience.

TinyPNG for WordPress

Reduce/Optimize Image Size by connecting to the TinyPNG API

WP Media Optimizer (.webp) vs TinyPNG for WordPress