From 17.1 Millimeters to 8.9 Millimeters: The Journey Behind a 48% Reduction in Thickness

From 17.1 Millimeters to 8.9 Millimeters: The Journey Behind a 48% Reduction in Thickness

Unveiled at Galaxy Unpacked 2025 in New York on July 9, the Galaxy Z Fold7 is 48% thinner than the original Galaxy Fold. While overall thickness¹ declined by 29% across the first six generations — from the Galaxy Fold in 2019 to the Galaxy Z Fold6 in 2024 — a significant 26% reduction was achieved in just the past year. This streamlined design reflects Samsung Electronics’ continued advancements in hinge engineering and product design, delivering a more refined user experience.

To highlight this milestone, Samsung Newsroom explores how the Galaxy Z Fold series has redefined thinness in foldable smartphones from 2019 to today.

Making its debut in 2019, the Galaxy Fold was Samsung’s first device to introduce the concept of foldable smartphones. With a maximum folded thickness² of 17.1 mm and a maximum unfolded thickness of 7.6 mm, the device offered the public its first look at foldable display technology. This revolutionary form factor ushered in a new mobile experience, allowing users to enjoy a widescreen display from the palm of their hand.

Introduced in 2020, the Galaxy Z Fold2 featured the Hideaway Hinge — consisting of more than 60 internal components for smoother, more flexible folding. The precision-engineered hinge integrated seamlessly into the device’s body, reducing the maximum folded thickness to 16.8mm and a maximum unfolded thickness to 6.9 mm.

In 2021, the Galaxy Z Fold3 became even more compact — measuring a maximum thickness of 16.0 mm when folded and 6.4 mm when unfolded — while also introducing support for the S Pen and IPX8-rated water resistance, both firsts for the series. Armor Aluminum was applied throughout the device to boost durability, and the upgraded Sweeper technology helped prevent dust and foreign particles from entering the hinge. These enhancements enabled a thinner, sturdier design without compromising usability.

Released in 2022, the Galaxy Z Fold4 brought notable improvements in both weight and thickness. The gear-based hinge was replaced with a linear movement mechanism, reducing internal components and resulting in a maximum folded thickness of 15.8 mm and an unfolded thickness of 6.3 mm. This redesign offered a sleeker profile and improved ergonomics while maintaining the device’s robust performance.

In 2023, the Galaxy Z Fold5 introduced the Flex Hinge, an innovative hinge mechanism with four drive shafts that enabled the display to curl inward in a water-drop shape, replacing the traditional Hideaway Hinge. This advancement enabled the two halves of the phone to close more evenly, minimising the screen crease and eliminating the gap when folded. The result was a more compact form factor, with a folded thickness of 13.4 mm and an unfolded thickness of 6.1 mm.

Unveiled in 2024, the Galaxy Z Fold6 delivered an even slimmer silhouette — just 12.1 mm when folded and 5.6 mm when unfolded. Featuring a refined structure and design of a symmetrical dual rail hinge, the device could be folded flat or opened to various angles between 75 and 115 degrees for greater versatility. This streamlined build further enhanced portability and everyday usability.

Now the thinnest Galaxy smartphone ever, the Galaxy Z Fold7 embodies years of design evolution. With a folded thickness of just 8.9 mm and an unfolded thickness of 4.2 mm, the device sets a new standard for slim foldables. At the core is the Armor FlexHinge — a new structural innovation that fuses advanced materials with an optimised design for superior durability and compactness. While the cover display of the Galaxy Z Fold6 measures 6.3 inches (158.9 mm), the Galaxy Z Fold7’s cover display extends to 6.5 inches (164.8 mm) to increase usability when the device is folded. The main display³ also spans 8.0 inches (203.1 mm) when unfolded, offering an 11% larger screen area than its predecessor — the biggest in the Z Fold series to date.

With each new generation, the Galaxy Z Fold series has advanced in both form and function — reducing thickness while expanding what’s possible in a mobile device. At the heart of this progress is Samsung’s continuous innovation in hinge technology. As the Galaxy Z Fold series pushes the boundaries of smartphone design, Samsung remains committed to unlocking transformative experiences with next-generation engineering and a foldable form factor like never before.

^[1]Unfolded thickness is measured from the main display to the rear glass. Folded thickness is measured from the cover display to the rear glass.
^[2]Maximum folded thickness refers to the thickest point of the device when it is folded shut, which is at its hinge.
^[3]Measured diagonally, the Galaxy Z Fold7’s main display size is 203.1 mm in the full rectangle; actual viewable area is less due to the rounded corners.