CopyTrans HEIC for Windows - A plugin that lets you view HEIC photos on Windows and convert them to JPG by right-clicking.
ImageGlass - You can use Image to view your digital images and photos of many different formats.
XnView MP - XnView is a free software that allows you to view, resize and edit your images. It supports more than 500 different formats!
Universal Viewer - Universal Viewer is an advanced file viewer for wide range of formats. Supported file formats are:
iMazing HEIC Converter - iMazing HEIC converter is a free Mac and PC app which converts photos from HEIC to JPEG or PNG.
Phiewer - Image Viewer - Phiewer is the easiest and fastest way to view your images, videos and even audio files.