Samsung Galaxy S25 Ultra VS Vivo iQOO 15

In terms of physical design, the Samsung Galaxy S25 Ultra and the Vivo iQOO 15 are remarkably close rivals. Both phones share an IP68 waterproof rating, meaning each can withstand submersion in fresh water up to the standard depth and duration — a meaningful durability perk for everyday use. Neither adopts a rugged build or a foldable form factor, placing them squarely in the conventional flagship slab category.

The dimensional differences are marginal but worth noting. The iQOO 15 is fractionally slimmer at 8.1 mm versus 8.2 mm, and its slightly narrower width of 76.8 mm compared to 77.6 mm may make it feel a touch more manageable in one hand during extended use. The S25 Ultra, meanwhile, is a whisker lighter at 218 g versus 220 g — a 2-gram gap that is imperceptible in daily handling. The iQOO 15's overall volume of 101.8 cm³ is slightly smaller than the S25 Ultra's 103.6 cm³, which aligns with its narrower footprint.

In practice, these two phones are essentially tied on design. The differences in dimensions and weight are too small to influence a purchasing decision on their own. Both deliver the same level of water protection, and neither offers any structural differentiator such as a rugged chassis. A user choosing between them based solely on form factor will find the experience nearly identical in hand.

Both screens share a strong foundation: OLED/AMOLED panels, identical peak brightness of 2600 nits, and the same HDR10 and HDR10+ support — meaning outdoor visibility and HDR content rendering will feel virtually equivalent on either device. Where things diverge is in the details that matter most to enthusiasts.

The iQOO 15 holds a tangible advantage in two key areas. Its 144Hz refresh rate outpaces the S25 Ultra's 120Hz, resulting in noticeably smoother scrolling and a more responsive feel during fast-paced gaming. Despite having a slightly smaller 6.85″ panel compared to the S25 Ultra's 6.9″, it also achieves a marginally higher pixel density of 508 ppi versus 498 ppi — a difference that is subtle but reflects slightly crisper fine detail at close viewing distances. The S25 Ultra counters with branded damage-resistant glass, which the iQOO 15 lacks entirely. This is a meaningful real-world consideration: without it, the iQOO 15's display is more vulnerable to scratches and accidental drops.

On balance, the iQOO 15 wins on raw display performance with its higher refresh rate and pixel density, making it the stronger choice for gamers and detail-focused users. However, the S25 Ultra's screen protection gives it a durability edge that could matter significantly over the lifespan of the device. Users who prioritize display longevity should weigh that trade-off carefully.

The chipset gap here is the headline story. The iQOO 15 runs on the Snapdragon 8 Elite Gen 5 — a newer generation than the Snapdragon 8 Elite powering the S25 Ultra. That generational step translates into a dramatic difference in the AnTuTu benchmark: the iQOO 15 scores an extraordinary 4,030,245 compared to the S25 Ultra's already-strong 2,207,809 — nearly double. This is not a marginal gap. In real-world terms, it points to significantly faster app launches, superior computational photography processing, and headroom for more demanding AI workloads.

CPU clock speeds reinforce this picture. The iQOO 15's performance cores run at 4.6 GHz versus the S25 Ultra's 4.47 GHz, and Geekbench 6 confirms the advantage in both single-core (3234 vs 3057) and multi-core (10059 vs 9846) results. The iQOO 15 also carries 16 GB of RAM against the S25 Ultra's 12 GB — extra headroom that benefits heavy multitaskers and users who keep many apps suspended in the background. Where the two phones are genuinely identical is in GPU architecture, memory bandwidth, TDP, and cache configuration, meaning thermal behavior and graphics throughput at equivalent workloads should be comparable.

The iQOO 15 holds a clear and meaningful performance advantage in this category. The newer chipset and additional RAM make it the stronger choice for users who demand peak computational power, whether for gaming, AI-driven features, or sustained multitasking.

The camera systems reveal a substantial gap between these two phones. The S25 Ultra deploys a four-lens array headlined by a 200 MP primary sensor — a pixel count that enables aggressive detail capture and flexible cropping — alongside a dedicated periscope lens delivering 5x optical zoom. The iQOO 15, by contrast, fields a triple-camera setup with a uniform 50 MP across all three lenses and only 3x optical zoom. For users who frequently shoot distant subjects, that zoom difference is tangible: 5x optical reach produces far cleaner results than digitally extending a 3x lens to match it.

Beyond resolution and zoom, the S25 Ultra stacks several additional advantages. Built-in optical image stabilization (OIS) is absent on the iQOO 15, which matters considerably for low-light photography and handheld video, where even slight camera shake degrades sharpness. The S25 Ultra also adds laser autofocus for faster, more confident locking in difficult lighting, a BSI sensor for improved light sensitivity, and HDR10 video recording support — none of which the iQOO 15 offers. The iQOO 15 does claim a higher-resolution 32 MP front camera versus the S25 Ultra's 12 MP, which may appeal to selfie-focused users.

This category belongs clearly to the Samsung Galaxy S25 Ultra. The combination of a higher-resolution primary sensor, greater optical zoom range, OIS, laser autofocus, and HDR10 video recording adds up to a more capable and versatile imaging system by a considerable margin. The iQOO 15's stronger front camera is a real but narrow bright spot that does not change the overall verdict.

The most immediate distinction is that the iQOO 15 ships with Android 16 while the S25 Ultra launches on Android 15. Running a newer OS version out of the box generally means access to the latest platform-level features and security patches from day one — a meaningful head start, particularly for users who care about longevity and keeping their software current.

Beyond the version number, the S25 Ultra accumulates several practical software advantages. It supports cross-site tracking blocking, a privacy feature the iQOO 15 omits, which matters for users who browse extensively and want tighter control over their digital footprint. Wi-Fi password sharing and focus modes — both absent on the iQOO 15 — are quality-of-life features that many users rely on daily for convenience and managing digital distractions. Most notably, the S25 Ultra can function as a PC replacement when connected to a display, a capability the iQOO 15 entirely lacks and one that meaningfully expands the device's utility for productivity-focused users.

This category is genuinely split. The iQOO 15 holds the edge on OS freshness with Android 16, but the S25 Ultra offers a richer day-to-day software experience through its broader feature set — particularly for privacy-conscious users and those who value desktop-mode productivity. Users who prioritize software versatility will find the S25 Ultra's ecosystem more complete overall.

Few spec categories produce a gap this decisive. The iQOO 15 packs a 7000 mAh battery against the S25 Ultra's 5000 mAh — a 40% larger cell that translates directly into significantly more time between charges. For heavy users who stream, game, or stay away from outlets for extended periods, that extra capacity is a genuine daily-life advantage rather than a number on a spec sheet.

The charging story is equally lopsided in the iQOO 15's favor. Its 100W wired charging is more than double the S25 Ultra's 45W, meaning it can replenish a much larger battery in a fraction of the time. Wireless charging follows the same pattern: 40W on the iQOO 15 versus 15W on the S25 Ultra — a difference that makes wireless top-ups a genuinely fast option rather than an overnight solution. The iQOO 15 also ships with a charger included, while the S25 Ultra does not, adding an immediate out-of-box convenience and cost consideration. The S25 Ultra's one exclusive here is reverse wireless charging, allowing it to top up accessories like earbuds or smartwatches — a useful but niche feature that does not offset the broader charging deficit.

The iQOO 15 wins this category comprehensively. Larger battery, dramatically faster wired and wireless charging, and a bundled charger — it outperforms the S25 Ultra on virtually every battery metric that affects daily usability.

Wired audio is off the table for both phones — neither includes a 3.5mm headphone jack — so the audio comparison centers entirely on wireless codec support and speaker output. On the speaker front, both deliver stereo sound and share a baseline of aptX and aptX HD support, ensuring solid Bluetooth audio quality with compatible headphones from either device.

Where they diverge is in their premium codec choices, and this is where headphone brand loyalty becomes the deciding factor. The S25 Ultra supports LDAC, Sony's high-resolution wireless codec capable of transmitting up to three times more data than standard Bluetooth — a significant advantage for users with Sony or LDAC-compatible headphones who want near-lossless wireless audio. The iQOO 15 skips LDAC entirely but instead offers aptX Adaptive, Qualcomm's next-generation codec that dynamically adjusts bitrate for both high-quality audio and low-latency performance — making it particularly well-suited for gaming headsets and real-time audio applications.

This category is a deliberate trade-off rather than a clear win for either side. Users invested in the Sony/LDAC ecosystem will find the S25 Ultra the natural fit, while those using aptX Adaptive-compatible headphones — or who value low-latency wireless audio — will get more from the iQOO 15. For anyone outside these specific ecosystems, the practical difference is negligible.

Shared groundwork is strong on both sides — 5G, Wi-Fi 7, USB 3.2 Type-C, NFC, and identical peak download and upload speeds mean neither phone is left behind on the fundamentals. The divergence emerges in the finer details of wireless and hardware extras. The iQOO 15 carries the newer Bluetooth 6.0 versus the S25 Ultra's 5.4, a generational step that brings improved connection reliability, better support for multi-device pairing, and reduced latency — a tangible benefit for wireless audio and peripheral users. It also adds an infrared sensor, enabling the phone to function as a universal remote for TVs and appliances — a niche but genuinely useful convenience the S25 Ultra lacks.

The S25 Ultra counters with its own set of meaningful advantages. It supports Wi-Fi 6E, extending Wi-Fi access into the less congested 6 GHz band for cleaner, faster connections in crowded environments — absent on the iQOO 15. Its SIM flexibility is also superior: dual physical SIM plus dual eSIM versus the iQOO 15's physical dual-SIM only, giving frequent travelers or users juggling multiple carriers far more options without swapping cards. The bundled stylus is a substantial productivity differentiator — one that opens up note-taking, sketching, and precision input workflows entirely unavailable on the iQOO 15.

On balance, the S25 Ultra holds the broader connectivity and features advantage. Wi-Fi 6E, eSIM support, and the included stylus add up to a more versatile package for power users and travelers. The iQOO 15's newer Bluetooth version and infrared sensor are useful additions, but they do not offset the S25 Ultra's wider feature reach in this category.

The miscellaneous specs for these two phones are identical across every data point provided. Both include a video light, and neither features a sapphire glass display, curved panel, or e-paper display. There is simply nothing here to separate them.

This category is a complete tie. No advantage exists for either device based on the available data, and no purchasing decision should be influenced by this group.