With show-font the user has the means to preview fonts inside of Emacs. It will preview with the font, if it is installed on the system, else it will provide a helpful message and an option to install the font (NOTE 2024-09-10: this only works on Linux). The user option show-font-character-sample provides a more complete character set that is intended for use in full buffer previews (i.e. not in the list of fonts).