Filestack - Filestack is file uploading software designed for cloud usage applications.
Cloudinary - Cloudinary is a cloud-based service for hosting videos and images designed specifically with the needs of web and mobile developers in mind.
Uploadcare - CDN, content delivery, content delivery network, file handling, image processing, cloud storage.
imgix - Real-time Image Processing. Resize, crop, and process images on the fly, simply by changing their URLs.
Transloadit - Versatile file uploading and processing service for developers
Cloudimage - Cloudimage.io is the easiest way to resize, store, and deliver your images to your customers through a rocket fast CDN.