If you're running Windows, you can now download the demo for Final Fantasy XV Windows Edition. The demo is available for download from three separate locations including Steam, Origin, and even the Windows 10 Store.

The demo weighs in at about 21GB and features 4K textures for those that like things crisp. Keep in mind that the full game will require at least 100GB of free space.
here for more details on the recommended hardware needed to optimally use these textures.

The FINAL FANTASY XV WINDOWS EDITION PLAYABLE DEMO is a preview of the full game. We will continue to work on all aspects to ensure FFXV WINDOWS EDITION will be a great experience for PC gamers.

Final Fantasy XV: Windows Edition will be released on March 6 and will include the base game and all major content expansions previous released for the consoles.