Flickr - image and video hosting website
CopyTrans HEIC for Windows - A plugin that lets you view HEIC photos on Windows and convert them to JPG by right-clicking.
Imgur - Imgur is a free and simple image hosting service with image editing feature. Signup is optional.
XnView MP - XnView is a free software that allows you to view, resize and edit your images. It supports more than 500 different formats!
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.
iMazing HEIC Converter - iMazing HEIC converter is a free Mac and PC app which converts photos from HEIC to JPEG or PNG.