macOS JXL support
macOS offers no native support for JPEG XL. No public plans exist if Apple enables support in the future. Still, you can use several free and publicly available image viewers to view JPEG XL images, including:
JXLook, a JPEG-XL viewer for macOS, also working with QuickLook PhotoQT, a simple yet powerful image viewer for Mac OS X XnView MP, an efficient multimedia viewer for macOS