XnView MP stands for Multi Platform = it is available for Windows, Linux and MacOS. It is a continuation of the older XnView Classic. In my opinion it is a great alternative to Windows photos app or any Linux image viewer that comes preinstalled. I even think it is an alternative to IrfanView. It is really fast and simple to use, supports more than 500 image formats, has built in folder browser, image converter, editor... AND MORE!
iMazing HEIC Converter - iMazing HEIC converter is a free Mac and PC app which converts photos from HEIC to JPEG or PNG.
IrfanView - IrfanView ... one of the most popular viewers worldwide.
Apowersoft Free HEIC Converter - Apowersoft Free HEIC Converter is a web-based application that helps to convert HEIF (.
FastStone Image Viewer - FastStone Image Viewer is a fast, stable, user-friendly image browser, converter and editor.
iMyFone HEIC Converter - iMyFone HEIC converter can convert your iPhone's HEIC photos to JPEGs on your computer without...
JPEGView - JPEGView is a small and fast viewer/editor for JPEG, BMP, PNG, GIF and TIFF images.