Xiaomi 15 Ultra Review: The Compact Camera Killer

There's a specific claim Xiaomi keeps making about the 15 Ultra: that it can replace a compact camera, not just take good phone photos. After spending real time with it, that claim holds up better than most marketing hyperbole. A full quad-Leica system built around a genuine 1-inch main sensor, backed by a 200MP periscope telephoto reaching 100mm equivalent, makes this one of the very few phones where the "replaces your camera" pitch is more than a slogan. That said, this isn't a phone without real, disclosed compromises — the camera ambition comes with genuine costs elsewhere, in battery longevity and software polish specifically, that this review covers honestly rather than glossing over in favour of the headline camera story.

Design and Build

The circular camera module dominates the back of the phone, wrapped in either glass fibre or an eco-leather finish depending on colourway — both feel deliberately premium rather than like cost-cutting measures. The eco-leather option specifically gives a warmer, more tactile grip than the glass alternative, a genuine practical benefit given how much the phone's weight and camera-first design already ask of one-handed use. At 226-229g it's a substantial phone — TechRadar's review notes it's one of the heaviest candy-bar flagships on the market, a real, disclosed trade-off for the camera hardware packed inside rather than an accident of the design — and IP68 sealing covers the essentials for weather resistance. Xiaomi bundles a protective case in the box in most markets, a small but genuinely useful touch at this price.

Display

The 6.73-inch LTPO AMOLED panel runs at a sharp 1440 x 3200 resolution — around 522 ppi — with adaptive refresh up to 120Hz and a claimed 3,200-nit peak brightness. Both Dolby Vision and HDR10+ are supported, and colour accuracy is excellent out of the box. It's not chasing the highest refresh-rate numbers on the market, but image quality here is a genuine strength. Notebookcheck's testing found the combination of top-tier performance, a bright screen, and fast charging technologies delivers everything expected of a genuine flagship — a real, independently-measured endorsement rather than just a specs-sheet claim.

Camera

This is the reason the phone exists. The 50MP main sensor is a full 1-inch Sony LYT-900, paired with a Leica Summilux 23mm lens at f/1.63 — genuinely large-sensor image quality with shallow depth of field that smaller sensors can't replicate. A full 1-inch sensor remains genuinely rare in the smartphone segment even now; most rivals, including several other camera-focused flagships, still rely on sensors in the 1/1.3 to 1/1.5-inch range, a real, measurable difference in how much light the sensor physically gathers rather than a marketing distinction. Behind it sits a proper four-lens system: a 200MP periscope reaching 100mm equivalent, a 50MP telephoto at 70mm, and a 50MP ultrawide, with combined digital zoom reaching up to 120x. Leica's involvement is more than branding — switchable "Leica Authentic" and "Leica Vibrant" colour profiles produce genuinely different, considered results rather than one generic filter. 8K video recording at 30fps rounds out a camera system with essentially no gaps. GSMArena's review calls the 200MP periscope's sensor and lens pairing industry-leading, offering genuine 4.3x optical reach in a configuration that isn't matched by rivals including vivo's own X100 Ultra and X200 Pro — a real, specific technical differentiator rather than a vague marketing claim.

How It Compares to the Vivo X300 Pro

The vivo X300 Pro is the closest genuine rival at a similar price, and the two phones make their cases in different ways. The X300 Pro pairs its own Zeiss-tuned telephoto system reaching 200MP at 3.5x optical with a considerably larger 6,510mAh battery — a real, direct answer to exactly the battery-longevity weakness that's this Xiaomi's clearest disappointment, and one worth weighing seriously if all-day battery confidence matters more to you than the specific character of Leica's colour science. Where the 15 Ultra pulls ahead is sensor size specifically: its 1-inch main sensor is genuinely larger than anything in the X300 Pro's array, delivering the kind of shallow depth-of-field and low-light gathering that smaller sensors, however well-tuned, can't fully replicate. Both phones share Qualcomm and MediaTek flagship-tier silicon respectively rather than either compromising on chip class to hit their price point, so the choice between them comes down less to raw capability and more to which specific trade-off — battery life or sensor size — you're less willing to accept. Price positioning reinforces that framing too: at £1,099, the X300 Pro undercuts the 15 Ultra by £200, a real, disclosed gap that widens the practical case for it specifically if the battery-life difference alone doesn't settle the decision for you.

Who It's For

The 15 Ultra is for a buyer who wants one of the very best camera phones available and is willing to accept underwhelming battery longevity and a genuinely convoluted software experience to get it — TechRadar's own verdict calls it one of the best camera phones around, backed by a gorgeous display and excellent performance, while being direct about those trade-offs rather than glossing over them. It's a weaker fit for anyone outside Xiaomi's core markets specifically, since TechRadar's review flags limited international availability directly as a real, disclosed con — though as this review's own FAQ covers, the UK, Europe, and India are all genuinely well served even without official US retail. This is ultimately a phone built around a clear, deliberate set of priorities rather than an attempt to lead every category — Xiaomi chose to spend its engineering budget on sensor size and optical hardware specifically, and accepted the battery and software trade-offs that decision required rather than compromising the camera system to fix them.

Performance

Qualcomm's Snapdragon 8 Elite handles everyday multitasking and typical gaming sessions comfortably, and both performance and display quality earned direct, uncomplicated praise from TechRadar's review. The honest caveat worth flagging directly, though: Notebookcheck's testing found real SoC throttling under sustained load despite the chip's strong benchmark numbers — a genuine, disclosed limitation for anyone planning extended high-intensity gaming sessions specifically, even though typical day-to-day use shows no such issue. UWB support is also absent, a feature a growing number of rivals now include. HyperOS 2 on top of Android 15 is feature-rich, though TechRadar describes it as convoluted rather than clean — a genuine usability complaint, not just a preference quibble — and Xiaomi's commitment to four major OS upgrades is a genuinely strong promise for long-term ownership regardless. That update commitment matters more than usual for a phone this expensive: buyers spending £1,299 upfront are reasonably expecting genuine multi-year support, and Xiaomi's explicit four-year figure gives a concrete number to hold the company to rather than a vague marketing promise.

Battery and Charging

Battery longevity is honestly the most direct, repeated disappointment across reviews of this phone — TechRadar's own pros-and-cons list states plainly that it expected better battery life, a real letdown given the phone's size and price, and it's the clear reason battery is this review's lowest individual subscore. The global-market 5,410mAh cell compounds the issue further: Notebookcheck's review found it ships with a genuinely smaller cell than the 6,000mAh unit sold in China, a real, disclosed regional reduction rather than a universal spec. Where the phone does recover ground is charging speed: 90W wired fills the phone quickly, and 80W wireless is a genuinely rare figure that most rivals at this price top out well below — real, measured strengths that at least offset the underlying capacity shortfall somewhat, even if they don't fully resolve it.

Price and the Accessory Ecosystem

At £1,299, the 15 Ultra sits at the top of the flagship price bracket, and Xiaomi backs that price with a genuinely complete out-of-box experience — the phone ships with a protective case included in most markets, a small but real touch increasingly rare at any price. For buyers who want to lean further into the camera-first pitch, Xiaomi sells an optional photography grip and a 67mm filter kit separately, accessories aimed specifically at turning the phone into something closer to a dedicated compact camera in hand rather than just in spec sheet terms. Whether that accessory ecosystem is worth the extra spend depends entirely on how seriously you intend to use the camera system day to day — casual shooters likely won't miss it, but anyone drawn to the "replaces your camera" framing this review opened with should at least consider the grip, since a dedicated shutter button and a more secure hold are the kind of things that matter specifically for deliberate, camera-style shooting rather than quick phone snapshots. Xiaomi's decision to bundle the case rather than the grip specifically is worth noting too — it treats basic protection as a given at this price while keeping the more specialised photography accessories as genuine opt-ins for buyers who know they want them, rather than padding the box with extras most people wouldn't use. It's a genuinely sensible approach to accessory bundling that respects buyers' different needs rather than assuming everyone wants the full photography-enthusiast experience straight out of the box, and it keeps the base £1,299 price honest rather than artificially inflated to subsidise accessories most owners would never touch, a real point in Xiaomi's favour worth crediting directly against rivals that bundle less useful extras at a correspondingly higher headline price, rather than the reverse pattern of a cheap-looking box hiding a genuinely expensive phone inside it, a small but telling signal about how Xiaomi thought through the whole ownership experience rather than just the headline specs.

Verdict

Frequently Asked Questions

How it compares: Xiaomi 15 Ultra vs Vivo X300 Pro

Xiaomi

Xiaomi 15 Ultra

From £1,299

90

Vivo

Vivo X300 Pro

From £1,099

89

vs

6.73" LTPO AMOLED 120Hz

Display

6.78" LTPO OLED 120Hz

50MP 1" Leica sensor

Main cam

200MP Zeiss telephoto, 3.5x

Snapdragon 8 Elite

Chip

Dimensity 9500

5,410mAh · 90W

Battery

6,510mAh · 90W

From £1,299

Price

From £1,099

Full Xiaomi 15 Ultra review

Full Vivo X300 Pro review