TinyPNG - Make your website faster and save bandwidth. TinyPNG optimizes your PNG images by 50-80% while preserving full transparency!
A.I. Gigapixel - AI based image resizer
ImageOptim - Faster web pages and apps.
AI Img Enlarger - Enlarge Images Without Losing Quality Online
TinyJPG - Compress JPEG images with perfect quality and file size
waifu2x - Online/Offline tool to upscale images