In implementations of application-based font previewing, a font preview system of a computing device receives a font file corresponding to a font of a font repository via a network. The font preview system encrypts font tables of the font file and the font preview system writes the encrypted font tables to a font disk cache of the computing device. The font preview system writes metadata describing the font tables to a font memory cache of the computing device. In response to receiving a request to preview the font from an application of the computing device, the font preview system uses the metadata to identify and decrypt a particular font table of the encrypted font tables, and the application renders glyphs of the font in a user interface using the decrypted particular font table.