Samsung's One UI 9 Spotted on Upcoming Foldables: Z Fold 8 and Z Flip 8 Test Builds Emerge

Samsung's software development pipeline appears to be moving at full speed, with the first evidence of One UI 9 testing emerging on the company's upcoming foldable devices. Despite One UI 8.5 not yet being released for current Galaxy devices, reliable leaker Tarun Vats has spotted test builds running on what appear to be the Galaxy Z Fold 8 and Z Flip 8, suggesting Samsung is already deep into development of its next major software iteration.

What's New in the Leak

The test builds reveal specific device codenames and build numbers that provide insight into Samsung's development process:

• Galaxy Z Flip 8: Codename SM-F776U with build numbers F776USQU0AZB1/F776UOYN0AZB1/F776USQU0AZB1
• Galaxy Z Fold 8: Codename SM-976U with build numbers F976USQU0AZB1/F976UOYN0AZB1/F976USQU0AZB1
• Mystery Fold Device: Codename SM-F971U with build F971USQU0AZB1

The build numbers follow Samsung's typical regional coding scheme, with the "U" suffix likely indicating US carrier variants. The presence of multiple build variants for each device suggests Samsung is conducting region-specific testing, which is standard practice for global device launches.

The Mystery Device: Samsung's Answer to Apple's Foldable

Perhaps most intriguing is the appearance of the SM-F971U codename, which reportedly represents a new foldable device designed to compete directly with Apple's rumored entry into the foldable market. According to the leak, this device will feature a more wide/square-ish aspect ratio compared to the traditional book-style foldables Samsung has produced.

This suggests Samsung is diversifying its foldable portfolio beyond the standard flip and fold form factors, potentially targeting users who prefer a different screen aspect ratio or usage pattern. The timing is particularly interesting given Apple's increasing focus on foldable technology.

Development Timeline and What It Means

The appearance of these test builds indicates Samsung's development cycle is progressing smoothly. Typically, manufacturers begin software testing several months before hardware finalization, allowing time for optimization and bug fixes.

With the Galaxy S26 series launching later this month, the foldable development timeline suggests:

• Q2 2026: S26 series launch with One UI 8.5
• Q3 2026: Z Fold 8 and Z Flip 8 announcement with One UI 9
• Late Q3 2026: Mystery foldable device potentially launching

This staggered approach allows Samsung to maintain market momentum throughout the year while giving each product line adequate development time.

One UI 9: What to Expect

While specific features of One UI 9 haven't been revealed, the early testing suggests Samsung is focusing on foldable-specific optimizations. Based on the company's development patterns, we can anticipate:

• Enhanced multitasking capabilities for larger foldable screens
• Improved continuity between cover and inner displays
• Refined gesture controls optimized for folding mechanisms
• Potential AI-powered features leveraging the expanded screen real estate

The fact that One UI 9 is being tested on foldables before other device categories suggests Samsung may be positioning its foldable lineup as the showcase for its latest software innovations.

Market Context and Pricing Concerns

Interestingly, this leak comes amid reports of price increases for the upcoming Galaxy S26 series, attributed to rising DRAM costs. The Korean pricing for the S26 series has already leaked, showing increases over their predecessors. This pricing pressure could extend to the foldable lineup as well, potentially pushing the Z Fold 8 and Z Flip 8 to even higher price points.

Looking Ahead

The emergence of these test builds provides the first concrete evidence of Samsung's next-generation foldable strategy. With the company reportedly working on multiple form factors and already deep into software development, the second half of 2026 promises to be an exciting period for foldable technology enthusiasts.

The combination of traditional flip and fold designs with a potentially new aspect ratio device suggests Samsung is hedging its bets across multiple foldable form factors, ensuring it maintains its leadership position regardless of which design philosophy ultimately gains mainstream acceptance.

As development continues, we can expect more details about One UI 9's features and the specific hardware improvements coming to the Z Fold 8 and Z Flip 8. The appearance of these test builds confirms that Samsung's foldable roadmap remains aggressive and forward-looking, even as the company navigates challenging component pricing environments.