March 2, 2025 | By Tech Spurt, Laptop Review Expert with Over a Decade of Tech Experience

Xiaomi’s “Ultra” line has a reputation for pushing boundaries, and the Xiaomi 15 Ultra doesn’t disappoint. Having spent a full week with this premium flagship as my daily driver, I can confidently say it’s a powerhouse contender for 2025’s best smartphone crown. From its jaw-dropping Leica-tuned cameras to its silky-smooth performance and eye-catching design, this phone screams luxury. But with a predicted UK price hovering around £1,249, is it worth the investment? As a seasoned mobile review expert, I’ve dissected every angle of this beast—here’s the full scoop on what makes the Xiaomi 15 Ultra tick.

Design and Build: A Premium Chunk of Tech

The Xiaomi 15 Ultra isn’t here to play small—it’s a hefty 226 grams, outmuscling rivals like the Samsung Galaxy S25 Ultra and sitting shoulder-to-shoulder with foldables like the Oppo Find N5. That massive camera bump isn’t just for show; it’s practically a mini ledge, doubling as a finger rest for one-handed grip—a thoughtful touch for a phone this big. Encased in Xiaomi’s Shield Glass 2.0, it’s drop- and scratch-resistant—I’ve seen it survive a couple of minor faceplants unscathed. Plus, there’s a pre-installed screen protector for extra peace of mind.

Flip it over, and you’re greeted with a classy two-tone finish: smooth glass meets soft-touch PU leather. It’s a standout in a sea of generic smartphones, resisting fingerprints and grime while offering a grippy feel. Little details—like the brushed metal camera ring and a subtle “Ultra” logo tucked in the corner—elevate its premium vibe. Color options are limited to black, white, or silver chrome, lacking the vibrant greens of the standard Xiaomi 15. With IP68 water and dust resistance, it’ll handle a splash or a sink dunk without breaking a sweat—though it falls short of the IP69 rating seen on phones like the Oppo Find X8 Pro.

• Pros: Unique two-tone design, grippy texture, IP68 rating.
• Cons: Limited color choices, no IP69 for extreme water resistance.

Display: A Visual Masterpiece for 2025

The 6.73-inch AMOLED display is a carryover from the Xiaomi 14 Ultra’s playbook, and that’s no complaint. With a crisp 3200×1440 resolution (522 PPI), full HDR10+, and Dolby Vision support, it’s a feast for the eyes. Colors strike a balance—vibrant yet natural—while contrast levels are downright stunning. Brightness? No issues here, even under harsh studio lights (or the rare UK sun). LTPO tech scales the refresh rate from 1Hz to 120Hz for buttery scrolling, and 1920Hz PWM dimming keeps flicker minimal—great news for OLED-sensitive users.

What sets it apart is the “wet touch” capability. Even with dripping hands, I could swipe through apps and notifications without the screen freaking out—a lifesaver in rainy weather. The subtle curve on all four edges gives it a sleek look while feeling practically flat, blending aesthetics with functionality. Whether you’re streaming Netflix, gaming, or browsing, this display rivals the best flagship phones of 2025.

• Standout Features: Wet-touch support, 120Hz refresh rate, flicker-free dimming.
• Ideal For: Media buffs, gamers, and anyone in wet climates.

Performance: Snapdragon 8 Elite Unleashed

Under the hood, the Xiaomi 15 Ultra packs Qualcomm’s Snapdragon 8 Elite chipset, paired with a whopping 16GB of RAM. Everyday tasks glide effortlessly—think app-switching, multitasking, and heavy browsing without a hiccup. For gamers, this is a dream machine. I cranked Genshin’s Impact to max settings, and the frame rate stayed rock-solid for over an hour with no dips or jitters. Xiaomi’s Ice Loop cooling system keeps thermals in check, so it never feels like a hot potato in your hand.

Storage starts at 512GB, with a 1TB option if you’re willing to splurge—HyperOS 2.0 takes up minimal space, so you’ve got room to hoard. Speaking of HyperOS, it’s built on Android 15 and offers a familiar yet polarizing experience. You’ve got an app tray, customizable notification effects, and a quirky always-on display selection, but quirks like tricky wallpaper swaps and Bluetooth streaming pauses (e.g., podcasts halting after notifications) can grate. Xiaomi hasn’t locked in OS update support yet, but as an Ultra-tier flagship, I’d wager on 3-4 years minimum—timely Android updates are a staple for their top dogs.

• Performance Highlights: Snapdragon 8 Elite, 16GB RAM, flawless gaming.
• Software Gripes: Minor HyperOS bugs, unclear update commitment.

Camera: Leica’s Finest Yet

The Leica-tuned quad-camera system is the Xiaomi 15 Ultra’s crown jewel. The 50MP Sony LYT-900 main sensor (23mm, f/1.6) leads the charge, cycling between 23mm, 28mm, and 35mm focal lengths with a tap. The variable aperture’s gone, but the Master Portrait mode nails creamy bokeh without overcooking your subject. High-contrast HDR shots shine—natural shadows, zero noise—leaving Samsung’s S25 Ultra and iPhones in the dust for low-light detail.

The lineup includes a 50MP Sony IMX858 telephoto (70mm, 3x zoom), a 200MP Samsung HP9 periscope (100mm, 4.1x zoom), and a 50MP Samsung JN5 ultra-wide (14mm). The 200MP periscope is a stunner—tack-sharp at long range, even in murky light, with minimal sharpening artifacts. Video tops out at 8K, but 4K 60 FPS with Dolby Vision across all lenses is the sweet spot—smooth stabilization and crisp quad-mic audio make it a vlogger’s delight. The 32MP front camera handles 4K video and video calls with ease, though soft lighting adds a touch of grain.

• Camera Strengths: Leica-tuned clarity, 200MP zoom, Dolby Vision video.
• Weaknesses: No variable aperture, motion blur in action shots.

Battery Life: All-Day Powerhouse

The 5,410mAh battery isn’t the largest—think Vivo X200 Pro’s beefier cell—but it’s no slouch. With mixed use (5-6 hours screen-on time, audio streaming), it ends the day with 35-40% left. Push it hard with 4K video or gaming, and it’ll dip into power-saving mode by nightfall, but I never drained it flat in 24 hours. Charging is where it flexes: 90W HyperCharge wired gets it full in a flash, while 80W wireless works with compatible pads—though that camera bump fusses with generic chargers.

• Battery Perks: Solid endurance, rapid charging.
• Caveat: Wireless charging quirks with standard pads.

Verdict: Does the Xiaomi 15 Ultra Live Up to the Hype?

The Xiaomi 15 Ultra is a flagship tour de force—phenomenal cameras, blistering performance, and a display that’s tough to beat, all wrapped in a premium, grippy shell. It’s not flawless—HyperOS has its quirks, and the £1,249 price tag (my educated guess) stings when rivals like the OnePlus 13 deliver similar specs for hundreds less. Still, for photography enthusiasts, power users, and anyone craving a standout device, this beast is worth every penny.

Compared to the Xiaomi 14 Ultra, the battery’s improved, the design’s refined, and the camera’s as dazzling as ever. It’s a love-it-or-hate-it phone—HyperOS quirks might irk some, but the hardware’s undeniable. So, is the Xiaomi 15 Ultra the best flagship phone of 2025? It’s in the running, and that’s saying something.

What’s your take—tempted by this Ultra beast? Let me know below!