XnView MP - XnView is a free software that allows you to view, resize and edit your images. It supports more than 500 different formats!
Flickr - image and video hosting website
IrfanView - IrfanView ... one of the most popular viewers worldwide.
Imgur - Imgur is a free and simple image hosting service with image editing feature. Signup is optional.
FastStone Image Viewer - FastStone Image Viewer is a fast, stable, user-friendly image browser, converter and editor.
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.