Flickr - image and video hosting website
Imgur - Imgur is a free and simple image hosting service with image editing feature. Signup is optional.
Google Photos - All your photos are backed up safely, organized and labeled automatically, so you can find them fast, and share them how you like.
500px - Connect, get inspired, and grow your skills.
Pixpa - Pixpa is an all-in-one platform to create beautiful, professional portfolio websites, client galleries and online stores without any coding knowledge.
ImageShack - Unlimited space to host images, easy to use image uploader, albums, photo hosting, sharing, dynamic image resizing on web and mobile.