ACDSee - ACDSee is an image viewer that uses very little system resources, and it has a small, sleek size that won't take up much space on your system.
Flickr - image and video hosting website
digiKam - Professional Photo Management with the Power of Open Source
Imgur - Imgur is a free and simple image hosting service with image editing feature. Signup is optional.
PhotoPrism.app - PhotoPrism® is an AI-Powered Photos App for the Decentralized Web. It makes use of the latest technologies to tag and find pictures automatically without getting in your way. You can run it at home, on a private server, or in the cloud.
XnView MP - XnView is a free software that allows you to view, resize and edit your images. It supports more than 500 different formats!