Asus Zenfone 12 Ultra VS Samsung Galaxy S25 Ultra

Both the Asus Zenfone 12 Ultra and the Samsung Galaxy S25 Ultra share the same IP68 waterproof rating, meaning both can withstand submersion in fresh water up to 1.5 meters for 30 minutes. Neither features a rugged build or a foldable form factor, so they sit in the same category of premium, conventional candybar smartphones with equivalent environmental protection.

Where a real difference emerges is in physical footprint. The two phones are nearly identical in width and height, but the Galaxy S25 Ultra is measurably slimmer at 8.2 mm versus the Zenfone 12 Ultra's 8.9 mm — a 0.7 mm gap that is noticeable when the devices are held side by side. That slimmer profile also translates into a significantly smaller overall volume: 103.6 cm³ for the S25 Ultra compared to 112.3 cm³ for the Zenfone 12 Ultra, roughly an 8% difference. In practice, a more compact volume means the S25 Ultra will feel less bulky in a pocket or a hand, even though the two phones share almost the same footprint on a flat surface.

Weight is essentially a draw at 218 g versus 220 g — a 2-gram delta that no user will perceive in daily use. Overall, the Samsung Galaxy S25 Ultra holds a clear design edge in this group: it achieves a noticeably thinner and more compact chassis while matching the Zenfone 12 Ultra on every protection metric.

On the fundamentals, these two phones share a solid common ground: both use OLED/AMOLED panels with Always-On Display, HDR10 support, and damage-resistant glass. The meaningful differences, however, run deep. The Galaxy S25 Ultra pulls ahead decisively in sheer visual fidelity — its 1440 x 3120 resolution at 498 ppi versus the Zenfone 12 Ultra's 1080 x 2400 at 388 ppi means noticeably sharper text, finer image detail, and a more refined viewing experience, particularly at close range. That 110 ppi gap is large enough to be perceptible to the naked eye.

Brightness tells an equally compelling story. The S25 Ultra's 2600 nits typical brightness towers over the Zenfone's 1600 nits, which translates directly into far better outdoor legibility on sunny days — a spec that matters significantly for everyday real-world use. The S25 Ultra also adds HDR10+ support, the dynamic metadata standard that enables scene-by-scene tone mapping for compatible streaming content, giving it a richer HDR experience. On the other hand, the Zenfone 12 Ultra counters with a higher 144Hz refresh rate versus the S25 Ultra's 120Hz, which can produce marginally smoother scrolling and animations — though in practice most users will not notice the difference between these two figures.

The glass story diverges too: Samsung's proprietary Gorilla Armor 2 is a distinct anti-reflective formulation designed to reduce glare, while the Zenfone uses the well-regarded Gorilla Glass Victus 2. The Samsung Galaxy S25 Ultra wins this category clearly, outperforming on resolution, pixel density, peak brightness, and HDR capability — the Zenfone's refresh rate advantage is real but not enough to offset those gaps.

The Asus Zenfone 12 Ultra and Samsung Galaxy S25 Ultra are both powered by the Qualcomm Snapdragon 8 Elite chipset, with the same Adreno 830 GPU. While both feature 3 nm semiconductor size and support 64-bit processing, there are some key differences in performance metrics. The Zenfone 12 Ultra has 16GB of RAM, while the Galaxy S25 Ultra offers 12GB. The Zenfone also has a larger internal storage option at 512GB, compared to the Galaxy S25 Ultra’s 1024GB.

In terms of benchmarking, the Zenfone 12 Ultra scores higher on AnTuTu, achieving 2,850,000 points, compared to the Galaxy S25 Ultra’s 2,207,809 points. Geekbench 6 results are also different: the Zenfone scores 10,059 on the multi-core test and 3,234 on the single-core test, while the Galaxy S25 Ultra scores 9,846 and 3,057, respectively.

Both devices have similar CPU configurations with 8 threads, using big.LITTLE technology, and clock speeds of 4.32 GHz for the high-performance cores and 3.53 GHz for the efficiency cores in the Zenfone 12 Ultra, compared to 4.47 GHz and 3.53 GHz in the Galaxy S25 Ultra. The GPU clock speed is slightly higher in the Galaxy S25 Ultra at 1200 MHz, compared to the Zenfone 12 Ultra’s 1100 MHz. However, both devices have identical RAM speeds (5300 MHz) and support for ECC memory, with a maximum memory bandwidth of 85.1 GB/s. Additional features, such as DirectX 12, OpenGL 3.2, and OpenCL 3, are common to both devices.

The Asus Zenfone 12 Ultra and Samsung Galaxy S25 Ultra both feature a multi-lens main camera, but with different configurations. The Zenfone 12 Ultra has a 50 MP, 32 MP, and 13 MP setup, while the Galaxy S25 Ultra offers a more advanced 200 MP, 50 MP, 50 MP, and 10 MP combination. The main cameras on both phones have wide apertures, with the Zenfone featuring f/1.9, f/2.4, and f/2.2, while the S25 Ultra’s lenses offer f/1.7, f/3.4, f/1.9, and f/2.4.

For video recording, the Zenfone 12 Ultra can shoot 4320 x 24 fps, while the Galaxy S25 Ultra records at 4320 x 30 fps. Both devices support slow-motion video, HDR recording, and can create panoramas in-camera. The Zenfone 12 Ultra has a 3x optical zoom, while the Galaxy S25 Ultra offers a stronger 5x optical zoom. Both phones feature phase-detection autofocus for photos, continuous autofocus for movies, and manual controls such as ISO, exposure, and white balance. The S25 Ultra also includes laser autofocus, which the Zenfone lacks.

For the front camera, the Zenfone 12 Ultra has a 32 MP lens with a f/2.5 aperture, while the Galaxy S25 Ultra has a 12 MP front camera with a f/2.2 aperture. Neither device has a front-facing LED flash or dual-lens front camera. Both phones support HDR10 recording, but neither supports Dolby Vision recording or 3D photo/video recording capabilities. Additionally, the S25 Ultra features two flash LEDs on its rear camera, while the Zenfone 12 Ultra has just one.

Both the Asus Zenfone 12 Ultra and Samsung Galaxy S25 Ultra run on Android 15 and offer a range of privacy and security features. Both devices include clipboard warnings, location privacy options, camera/microphone privacy options, and the ability to block app tracking. However, the Galaxy S25 Ultra has the added benefit of blocking cross-site tracking, which the Zenfone 12 Ultra does not.

Both phones also support theme customization, dark mode, dynamic theming, and customizable notifications. The Zenfone 12 Ultra offers features such as the ability to offload apps, full-page screenshots, split screen support, and PiP (Picture-in-Picture) mode, which are also present on the Galaxy S25 Ultra. The S25 Ultra further adds focus modes, Wi-Fi password sharing, and the ability to be used as a PC, which are not available on the Zenfone.

Both devices have features like Live Text, offline voice recognition, voice commands, and the ability to track the current position of a mobile device. Additionally, both phones are multi-user systems and support widgets. Neither phone provides direct OS updates, and neither includes Quick Start functionality. Both devices support sharing intents and have a child lock, ensuring user control over content and app sharing.

The Asus Zenfone 12 Ultra and Samsung Galaxy S25 Ultra both feature wireless charging and support fast charging, but with some differences in performance. The Zenfone 12 Ultra has a larger 5500 mAh battery, compared to the S25 Ultra's 5000 mAh. The Zenfone supports faster wired charging at 65W, while the Galaxy S25 Ultra supports 45W charging speed. Both devices offer 15W wireless charging, but the S25 Ultra also supports reverse wireless charging, which the Zenfone 12 Ultra does not.

Both phones come with a charger included in the box, but the Galaxy S25 Ultra does not provide a charger, while the Zenfone 12 Ultra does. Neither device has a removable battery, and both feature a rechargeable battery. Both devices have a battery level indicator to monitor power levels during use.

In terms of features, both devices support wireless charging and have a rechargeable battery. However, the main differences come in the charging speeds and the reverse wireless charging feature available on the Galaxy S25 Ultra.

The Asus Zenfone 12 Ultra and Samsung Galaxy S25 Ultra differ when it comes to audio features. The Zenfone 12 Ultra includes a 3.5 mm audio jack, which the Galaxy S25 Ultra lacks. Both devices are equipped with stereo speakers for enhanced audio playback. When it comes to Bluetooth audio technologies, the Zenfone 12 Ultra supports aptX, aptX HD, aptX Adaptive, and aptX Lossless, while the Galaxy S25 Ultra supports aptX, aptX HD, and LDAC, but lacks support for aptX Adaptive and aptX Lossless.

In terms of microphones, the Zenfone 12 Ultra has 2 microphones, while the Galaxy S25 Ultra has 3 microphones, likely providing a slight advantage in terms of audio capture quality and noise cancellation.

Neither device includes a radio, with both opting for modern wireless streaming options instead. Overall, the main differences are in the presence of the 3.5 mm audio jack on the Zenfone and the slightly better microphone setup on the Galaxy S25 Ultra.

The Asus Zenfone 12 Ultra and Samsung Galaxy S25 Ultra both support 5G connectivity and offer similar Wi-Fi capabilities, including Wi-Fi 4, Wi-Fi 5, Wi-Fi 6, Wi-Fi 6E, and Wi-Fi 7. Both phones have USB Type-C ports, NFC, and Bluetooth 5.4. The Zenfone 12 Ultra supports 2 SIM cards and 1 eSIM, while the Galaxy S25 Ultra supports 2 SIM cards and 2 eSIMs, offering slightly more flexibility for multiple carrier options.

In terms of sensors, both devices include a gyroscope, accelerometer, GPS, and compass. The Galaxy S25 Ultra also includes a barometer, which is not available on the Zenfone 12 Ultra. Additionally, the Zenfone 12 Ultra supports Galileo, while both devices support GPS, but only the S25 Ultra has a heart rate monitor and ANT+ support for fitness tracking.

Neither device includes a stylus by default, but the Galaxy S25 Ultra does support a stylus (though it is not included), whereas the Zenfone 12 Ultra has no mention of stylus support. Both phones have fingerprint scanners and support cellular connectivity. Other features such as motion tracking, optical tracking, and a built-in projector are not present on either device.

Both the Asus Zenfone 12 Ultra and Samsung Galaxy S25 Ultra feature a video light, but neither device includes sapphire glass for the display. Additionally, both smartphones have flat displays, as neither offers a curved display. There is also no e-paper display on either model, so both phones are similar in these aspects.

In summary, while both devices share the same features in this group, such as video lights and flat, non-sapphire displays, there are no significant differences between them in this category.