The demo is 18.641 GB.
Here’s a blurb from the PlayStation Blog detailing what you can expect from the demo, which contains roughly the game’s first two and half hours.
The demo will give PlayStation 5 players a taste of the game’s vibrant world and fast-paced action combat with two lengthy sections showcasing what you can expect from FFXVI. The first is the game’s opening prologue, approximately a two and half hour slice of gameplay giving players insight into Clive Rosfield’s past and the events that set him on his present day journey. Save data from this portion can be carried over to the main game when it launches next week.
Completing the prologue then unlocks a special battle demo, approximately a two-hour, action-heavy segment. This features an infiltration of a fort at night, with Clive supported on his mission by his faithful wolf Torgal and Cidolfus Telamon. You’ll encounter various enemies and epic bosses. While you won’t be able to save your progress in this segment of the demo, it will let you test out the fuller range of combat options by way of numerous unlocked abilities and accessories. This can be replayed as many times as you’d like, giving players a head start on experiencing Clive’s full-fledged action battles. Need a primer? Get an idea of what to expect here.
Final Fantasy XVI is available now for pre-order and will release on June 21st on PS5.