Image Viewers
On Windows, IrfanView is still the best, but it takes time to configure it properly.
XnView MP, also known as MP, is a newer and improved version of XnView, also known as “Classic” XnView. To install, use scoop install xnviewmp, and on macOS, use brew.
FastStone Image Viewer is better suited for me than their other program, MaxView and it offers interesting options such as JPEG manipulation without recompression.
IrfanView is the most popular and better optimized. For example, XnView takes up to 20MB, while IrfanView is only 3MB in size. Currently, I prefer XnView as it feels more user-friendly to me. IrfanView only drawback is that it is only available for Windows.
ImageGlass can be installed with Scoop, but it is not the most efficient program as it is around 50 MB in size. However, it closely resembles the Windows UI and could serve as a replacement for the built-in Photos app. It supports a variety of formats, although the options are basic but logically organized.
The software programs XnView and IrfanView support “lossless cropping,” but I am not certain about the others.
Cross-Platform Image Tools
Here are my old acquaintances that are cross-platform and undoubtedly almost perfect, XnView MP and its companion from the same authors, XnConvert. Both are, of course, open-source and can be installed with brew install xnviewmp xnconvert.
For support for new formats on macOS and Homebrew, it is easy to install the official Google webp library. Also, take a look at various Quick Look plugins for Finder. I’m not sure what to use for image preview in Double Commander, but I think XnView MP is still ideal because it can preview text, audio, or video files.
WebPonize is a macOS application specifically developed to convert images to WebP format. It is written in native Swift. The repository for this application can be found at webponize/webponize. Manual installation is required but not possible as it is not available on Homebrew or the Apple Store.
nomacs/nomacs is an open-source multi-platform program available on its homepage nomacs.org. On Windows, it cannot be compared to the others, but it comes close. However, it is the only program that works everywhere and has some interesting options, such as viewer synchronization to synchronize multiple instances in the LAN and AVIF support. To install, use scoop install nomacs. I haven’t tried it on macOS because the installation is complicated and I couldn’t find prebuilt binaries.
Image Optimization Tools
The following tools are more focused on compression optimization rather than conversion.
The Caesium image compression software is a highly efficient cross-platform tool written in C++. You can find the repository at Lymphatus/caesium-image-compressor. This software supports JPG, PNG, and WebP formats, enabling you to reduce file size while preserving image quality. However, manual installation is required.
For those using macOS, Windows, or Linux, the Imagine app is a cross-platform solution for optimizing PNG, JPEG, and WebP images. It is built on Electron and offers comprehensive optimization capabilities.
Hummindbird is a compression app that supports various formats including jpg, png, webp, svg, gif, css, js, and html. It is compatible with both macOS and Windows and is built on the Electron framework.