Imagify - Online and CMS Image Compression Made Easy
Image Compression
Image Optimization and Compression Plugin for WordPress and API by ShortPixel
ShortPixel is an image optimization and compression API and WordPress plugin that helps improve your website performance. Lossy, glossy and lossless compression available.
The #1 image optimizer for WordPress Agencies - WP Compress
TinyPNG – Compress PNG images while preserving transparency
Gumlet - Real-time Image Optimisation and Global CDN
EWWW Image Optimizer