Galaxy Z Fold 8 Ultra measures just 4.1 mm thick when unfolded — 0.1 mm thinner than its predecessor — making it Samsung’s thinnest “book-style” Z Fold to date.
A steady push toward thinner foldables
From the first Fold, Samsung’s book-style devices have been thicker than conventional smartphones. Each generation has trimmed that profile, with a notable leap last year when the Galaxy Z Fold 7 brought the Fold’s footprint closer to some Chinese rivals and many non-foldable flagships. The Fold 8 Ultra continues that trajectory, shaving off another fraction of a millimeter — a small numerical change that can nonetheless be noticeable in hand.
Thinner chassis, upgraded components
Samsung hasn’t traded performance for slimness. The Galaxy Z Fold 8 Ultra ships with improved external and internal displays, a more powerful chipset, an upgraded rear camera system, new connectivity options, and faster charging. These upgrades have been integrated while reducing the device’s thickness.
Bigger battery thanks to new chemistry
Contrary to the usual trade-off — larger battery equals a thicker chassis — Samsung says it has increased battery capacity while making the phone slimmer. The company attributes this to a silicon-carbon battery chemistry, which allows higher capacity without adding thickness. Samsung also notes that the phone’s weight remains unchanged from the previous model.
What this means for users
A 0.1 mm reduction may sound marginal on paper, but combined with other refinements it improves grip and brings the unfolded experience closer to that of a traditional smartphone. Preserving weight while increasing battery capacity and modernizing the internals signals Samsung’s intent to refine Fold ergonomics without compromising performance or endurance.
Bottom line
By delivering its thinnest Fold yet alongside modernized components and a new battery chemistry, Samsung continues its gradual slimming strategy for foldables while maintaining power and battery life.
