Samsung Galaxy S26 Ultra vs Xiaomi 15 Ultra: Ultra Power Meets Xiaomi's Camera Champion

The Samsung Galaxy S26 Ultra and Xiaomi 15 Ultra represent two very different flagship smartphones — Samsung's ultra-premium hardware powerhouse versus Xiaomi's camera-focused 2025 champion. Samsung's Ultra flagship pushes every spec to its maximum — the largest screen, the highest resolution camera, the most RAM, and the most features for $1,299. The Xiaomi 15 Ultra, Xiaomi's 2025 camera-focused flagship, features a 6.73-inch AMOLED display with a 200MP quad-camera system for $1,199.

At $1,299 for the Galaxy S26 Ultra and $1,199 for the Xiaomi 15 Ultra, these serve fundamentally different purposes. Samsung offers maximum hardware capability in the S26 Ultra, while Xiaomi offers the best camera system and battery life at a lower price.

Design and Build Quality

The Samsung Galaxy S26 Ultra features a titanium frame with Gorilla Armor 2 glass protection. The S26 Ultra measures 162.3 x 77.4 x 8.6mm and weighs 233g — one of the largest flagship phones available. The integrated S Pen silo adds functionality.

The Xiaomi 15 Ultra features an aluminum frame with Xiaomi Dragon Glass protection. The Xiaomi 15 Ultra measures 162.0 x 75.0 x 9.4mm and weighs 225g — slightly lighter but thicker with a larger camera module.

The Galaxy S26 Ultra wins on build quality, premium materials, and S Pen functionality. The Xiaomi 15 Ultra wins on weight and camera hardware.

Display

Samsung Galaxy S26 Ultra Display:

6.9-inch Dynamic AMOLED 2X
2,600 nits peak brightness
120Hz adaptive refresh rate (1-120Hz)
QHD+ resolution (3120 x 1440)
Gorilla Armor 2 protection

Xiaomi 15 Ultra Display:

6.73-inch AMOLED (LTPO)
3,200 nits peak brightness
120Hz adaptive refresh rate (1-120Hz)
Xiaomi Dragon Glass

The Xiaomi 15 Ultra's display is brighter (3,200 vs 2,600 nits). The Galaxy S26 Ultra has a slightly larger display (6.9 vs 6.73 inches) and higher resolution.

Samsung S26 Ultra wins on display size and resolution. Xiaomi 15 Ultra wins on brightness.

Camera System

Samsung Galaxy S26 Ultra Camera:

200MP main sensor (f/1.7, OIS)
12MP ultrawide (f/2.2, 120°)
50MP telephoto (f/3.4, 5x optical zoom, OIS)
10MP telephoto (f/2.4, 3x optical zoom, OIS)
12MP front camera (f/2.2)

Xiaomi 15 Ultra Camera:

50MP main sensor (f/1.63, OIS, 1-inch sensor)
50MP ultrawide (f/2.2, 122°)
50MP telephoto (f/2.5, 3.2x optical zoom, OIS)
50MP periscope telephoto (f/3.0, 5x optical zoom, OIS)
32MP front camera (f/2.0)

The Xiaomi 15 Ultra's camera system is significantly better. The 1-inch main sensor captures far more light, and the quad-camera system (50MP + 50MP + 50MP + 50MP) provides more consistent quality across all lenses. The 32MP front camera (vs 12MP) is dramatically better. The S26 Ultra has a higher resolution main sensor (200MP) but smaller sensor size.

Xiaomi 15 Ultra wins on camera by a significant margin.

Performance

Samsung Galaxy S26 Ultra Performance:

Snapdragon 8 Elite Gen 2 (3nm TSMC)
12GB RAM
256GB / 512GB / 1TB storage (UFS 4.0)
S Pen support (built-in)

Xiaomi 15 Ultra Performance:

Snapdragon 8 Elite (3nm TSMC)
16GB RAM
256GB / 512GB / 1TB storage (UFS 4.0)

The Samsung Galaxy S26 Ultra's processor is faster (Gen 2 vs original Elite). The Xiaomi 15 Ultra has more RAM (16GB vs 12GB). Both have UFS 4.0 storage and similar storage options.

Samsung S26 Ultra wins on processor generation and S Pen. Xiaomi 15 Ultra wins on RAM.

Battery Life and Charging

Samsung Galaxy S26 Ultra Battery:

5,000mAh battery
45W wired fast charging
15W wireless charging

Xiaomi 15 Ultra Battery:

5,800mAh battery
90W wired fast charging
50W wireless charging

The Xiaomi 15 Ultra has a larger battery (5,800 vs 5,000mAh) and dramatically faster charging (90W vs 45W wired, 50W vs 15W wireless).

Xiaomi 15 Ultra wins on battery capacity and charging speed by a huge margin.

Software Experience

The Galaxy S26 Ultra runs Android 15 with One UI 7. The Xiaomi 15 Ultra runs Android 15 with HyperOS 2.

Samsung S26 Ultra wins on software updates and ecosystem. Xiaomi 15 Ultra wins on customization and features.

Value Proposition

The Samsung Galaxy S26 Ultra at $1,299 offers maximum hardware capability. The Xiaomi 15 Ultra at $1,199 offers the best camera system and battery life at a lower price.

Choose the Samsung Galaxy S26 Ultra if you want the absolute best in every metric. The S26 Ultra is the phone for users who want the best camera hardware, display, and performance available.

Choose the Xiaomi 15 Ultra if you want the best camera and battery experience. The Xiaomi 15 Ultra is ideal for users who prioritize photography and battery life.

Final Verdict

The Samsung Galaxy S26 Ultra vs Xiaomi 15 Ultra comparison is a contest between ultra-premium hardware excellence and camera-focused innovation. The S26 Ultra wins on display size, resolution, processor performance, software updates, build quality, and S Pen. The Xiaomi 15 Ultra wins on display brightness, camera, RAM, battery capacity, and charging speed, and value ($100 cheaper).

Both devices serve their intended audiences. The Galaxy S26 Ultra is the premium smartphone choice at $1,299. The Xiaomi 15 Ultra is the camera champion at $1,199.