Xiaomi 15 (China 512GB/12GB) vs Samsung Galaxy S21 Ultra (SM-G998U1 512GB)
Side by side comparison between Xiaomi 15 vs Samsung Galaxy S21 Ultra phones, differences, pros, cons and full specifications. What's the better?
,
6.36"
AMOLED
AMOLED
1200x2670
50
MP
MP
32mp
12GB
RAM
RAM
Octa-core
5400
mAh
mAh
(Non removable)
vs
6.8"
AMOLED
AMOLED
1440x3200
108
MP
MP
40mp
16GB
RAM
RAM
Octa-core
5000
mAh
mAh
(Non removable)
What's the better phone? Xiaomi 15 (China 512GB/12GB)
The phonemore's choice is much more technical than personal. Therefore, you shouldn't only consider this. Our goal is to help you, but what's important to us may not be important to you. You decide which one is the best! Comment!
14 Advantages 
9 Advantages | 38 Common items in both devices |
| 512GB (458GB available) / 512GB (457GB available) |
| Aluminum body, glass front / Aluminum frame, glass front/back |
| LTPO AMOLED / Dynamic AMOLED |
| Dolby Vision/HDR10+ / HDR10+ |
| 120Hz |
| Digital and optical zoom |
| PDAF: phase detection autofocus / PDAF: phase detection autofocus on both cameras |
| +31 specs and more in the table below |
Check the comparison table below for more items that are not evaluated in comparison score above.
Highlight differences Clear highlight📱 Model features | ||
| Xiaomi 15 (China 512GB/12GB) | Galaxy S21 Ultra (SM-G998U1 512GB) | |
| Model | Xiaomi 15 (China 512GB/12GB) | Galaxy S21 Ultra (SM-G998U1 512GB) |
| Other model names | Xiaomi 15 24129PN74C | Galaxy S21 Ultra 5G (SM-G998U1) Unlocked |
| Country or region available |  China |  USA |
| Brand | Xiaomi | Samsung |
| Release date | 10/29/2024 | 1/29/2021, Announced: 1/14/2021 |
| Depth | 8.4 millimeters (0.33 inches) | 8.9 millimeters (0.35 inches) |
| Size (width x height) | 71.2 x 152.3 millimeters (2.8 x 6 in) | 75.6 x 165.1 millimeters (2.98 x 6.5 in) |
| Weight | 192 grams (6.72 ounces) | 227 grams (7.95 ounces) |
| Build, materials | Aluminum body, glass front | Aluminum frame, glass front/back |
| Protection against water and others | IP68 certified: water-resistant up to 1.5 meters for 30min and dust-resistant | IP68 certified: water-resistant up to 1.5 meters for 30min and dust-resistant |
📲 Display | ||
| Xiaomi 15 (China 512GB/12GB) | Galaxy S21 Ultra (SM-G998U1 512GB) | |
| Display type | LTPO AMOLED | Dynamic AMOLED |
| Screen size | 6.36" inches | 6.8" inches |
| Screen-to-body ratio | ~90% (screen-to-body ratio) | ~89.4% (screen-to-body ratio) |
| Display resolution | 1200x2670 pixels (20:9) | 1440x3200 pixels (20:9) |
| Touchscreen | Capacitive Multitouch 10-points | Capacitive Multitouch 10-points |
| Pixel density (dot pitch) | 460 PPI | 516 PPI |
| Colors | 68 billion | 16 million |
| Scratch-resistant glass | Dragon Crystal Glass | Gorilla Glass Victus |
| Refresh rate | 120Hz | 120Hz |
| Display features | 3200nits[peak] Dolby Vision/HDR10+ Touch Sampling Rate: 300Hz | 1500nits[peak] HDR10+ Always-On Display |
🤖 Operating System | ||
| Xiaomi 15 (China 512GB/12GB) | Galaxy S21 Ultra (SM-G998U1 512GB) | |
| System version | Android 15 | Android 11 |
| Firmware update | feature not registered | Android 15 |
| User Interface | HyperOS 2 | One UI 3.1 / 4.1 / 5.1 / 6.0 / 7.0 |
⚙️ Processor | ||
| Xiaomi 15 (China 512GB/12GB) | Galaxy S21 Ultra (SM-G998U1 512GB) | |
| Chipset | 64bit: Qualcomm Snapdragon 8 Elite (SM8750-AB) (3nm) | 64bit: Qualcomm Snapdragon 888 (SM8350) (5nm) |
| CPU | Octa-core, 2 processors: 2x 4.32GHz Oryon V2 Phoenix L (Dual-core) 6x 3.53GHz Oryon V2 Phoenix M (Hexa-core) | Octa-core, 3 processors: 1x 2.84GHz Kryo 680 (Single-core) 3x 2.42GHz Kryo 680 (Triple-core) 4x 1.8GHz Kryo 680 (Quad-core) |
| GPU graphical controller | Qualcomm Adreno 830 (1100MHz) | Qualcomm Adreno 660 (840MHz) |
| Performance (benchmark) | AnTuTu: 2534643 (v10) Geekbench: 9419 (v6) | AnTuTu: 681099 (v8), 809165 (v9) Geekbench: 3539 (v5.2) GFXBench: 54fps (ES 3.1 onscreen) |
💽 Memory and storage | ||
| Xiaomi 15 (China 512GB/12GB) | Galaxy S21 Ultra (SM-G998U1 512GB) | |
| RAM memory | 12GB LPDDR5X | 16GB LPDDR5 |
| Internal storage | 512GB (458GB available) UFS 4.0 | 512GB (457GB available) UFS 3.1 |
| External storage | Not supported | Not supported |
📶 Mobile networks | ||
| Xiaomi 15 (China 512GB/12GB) | Galaxy S21 Ultra (SM-G998U1 512GB) | |
| Dual-SIM | Dual-SIM Standby - Call active on one sim card | Dual-SIM Standby - Call active on one sim card |
| SIM card | 2 slots (Dual-SIM) nano-SIM (4FF) + e-SIM | 1 slot (Single-SIM) nano-SIM (4FF) + e-SIM |
| Maximum Download / Upload | 3000/1024 Mbps | 5000/1920 Mbps |
| Network technology | 2G, 3G, 4G, 5G | 2G, 3G, 4G, 5G |
| Frequency, bands | Expand band details Collapse details | |
| GSM MHz band | Quad-Band 850/900/1800/1900 | Quad-Band 850/900/1800/1900 |
| Primary 2G network | GSM 850/900/1800/1900 | CDMA 800/1900, GSM 850/900/1800/1900 |
| Primary 3G network | UMTS 850/900/1700/1900/2100 | CDMA2000 1xEV-DO UMTS 850/900/1700/1900/2100 |
| Primary 4G network | LTE Cat20 (1, 2, 3, 4, 5, 7, 8, 12, 17, 18, 19, 20, 26, 28, 66) TD-LTE (34, 38, 39, 40, 41, 42, 48) VoLTE | LTE Cat20 (1, 2, 3, 4, 5, 7, 8, 12, 13, 14, 18, 19, 20, 25, 26, 28, 30, 66, 71) TD-LTE (38, 39, 40, 41, 46, 48) VoLTE |
| Primary 5G network | SA/NSA/Sub6 (1, 2, 3, 5, 12, 20, 26, 28, 38, 40, 41, 48, 66, 77, 78, 80, 81, 83, 84, 89) | SA/NSA/Sub6 (2, 5, 25, 41, 66, 71) mmWave (260, 261) |
| Primary data network | GPRS, EDGE, UMTS, HSDPA, HSUPA, HSPA+, TD-LTE, LTE, LTE-A, SA/NSA, Sub6 | GPRS, EDGE, CDMA2000 EV-DO Rev 0, CDMA2000 EV-DO Rev A, UMTS, HSDPA, HSUPA, HSPA+, TD-LTE, LTE, LTE-A, SA/NSA, Sub6 |
| Secondary 2G network | GSM 850/900/1800/1900 | CDMA 800/1900, GSM 850/900/1800/1900 |
| Secondary 3G network | UMTS 850/900/1700/1900/2100 | CDMA2000 1xEV-DO UMTS 850/900/1700/1900/2100 |
| Secondary 4G network | LTE Cat20 (1, 2, 3, 4, 5, 7, 8, 12, 17, 18, 19, 20, 26, 28, 66) TD-LTE (34, 38, 39, 40, 41, 42, 48) VoLTE | LTE Cat20 (1, 2, 3, 4, 5, 7, 8, 12, 13, 14, 18, 19, 20, 25, 26, 28, 30, 66, 71) TD-LTE (38, 39, 40, 41, 46, 48) VoLTE |
| Secondary data network | GPRS, EDGE, UMTS, HSDPA, HSUPA, HSPA+, TD-LTE, LTE, LTE-A, SA/NSA, Sub6 | GPRS, EDGE, CDMA2000 EV-DO Rev 0, CDMA2000 EV-DO Rev A, UMTS, HSDPA, HSUPA, HSPA+, TD-LTE, LTE, LTE-A, SA/NSA, Sub6 |
📷 Camera | ||
| Xiaomi 15 (China 512GB/12GB) | Galaxy S21 Ultra (SM-G998U1 512GB) | |
| Back camera (main camera) | (triple camera) 50 megapixels 50MP telephoto f/2.060mm1/2.76"0.64µmPDAFOIS2.6x-optical-zoom 50MP ultrawide f/2.214mm115°1/2.76"0.64µm | (quad camera) 108 megapixels 10MP periscope telephoto f/4.9240mm1/3.24"1.22µmPDAFOIS10x-optical-zoom 10MP telephoto f/2.470mm1/3.24"1.22µmPDAFOIS3x-optical-zoom 12MP ultrawide f/2.213mm1/2.55"1.4µmPDAFSuper-Steady-video |
| Main camera resolution | 8160x6120 pixels | 12000x9000 pixels |
| Video recording (primary) | 8K UHD (7680x4320) 30 fps | 8K UHD (7680x4320) 24 fps |
| Flash | Dual-LED flash | LED flash |
| Focal aperture | f/1.6 (aperture) | f/1.8 (aperture) |
| Focal length | 23mm (lens) | 26mm (lens) |
| Sensor size | 1/1.31" inches | 1/1.33" inches |
| Pixel size | 1.2µm pixel | 1.8µm pixel |
| Autofocus | PDAF: phase detection autofocus | PDAF: phase detection autofocus on both cameras |
| Touch focus | Supported | Supported |
| Image stabilization | OIS: Optical stabilization | OIS: Optical stabilization |
| Zoom | Digital and optical zoom | Digital and optical zoom |
| Face/smile detection | Face detection, Smile detection | Face detection, Smile detection |
| BSI sensor | Supported | Supported |
| HDR | HDR photo/video on both cameras | HDR photo/video on both cameras |
| Camera extras | 8K@24/30fps (HDR) 4K@24/30/60fps (HDR10+, 10-bit Dolby Vision HDR, 10-bit LOG) 1080p@30/60/120/240/960fps 720p@1920fps Leica Summilux | 4K@60fps 1080p@240fps 720p@960fps |
📸 Front camera | ||
| Xiaomi 15 (China 512GB/12GB) | Galaxy S21 Ultra (SM-G998U1 512GB) | |
| Front camera (secondary) | 32 megapixels | 40 megapixels |
| Front camera resolution | 6528x4896 pixels | 7296x5472 pixels |
| Video recording (secondary) | 4K UHD (3840x2160) | 4K UHD (3840x2160) |
| Front flash | Not supported | Not supported |
| Focal aperture | f/2.0 (aperture) | f/2.2 (aperture) |
| Focal length | 21mm (lens) | 26mm (lens) |
| Sensor size | 1/3.14" inches | 1/2.8" inches |
| Pixel size | 0.7µm pixel | 0.7µm pixel |
🔉 Sound and multimedia | ||
| Xiaomi 15 (China 512GB/12GB) | Galaxy S21 Ultra (SM-G998U1 512GB) | |
| Loudspeaker | Stereo sound 24-bit/192kHz Dolby Atmos Hi-Res | Stereo sound 32-bit/384kHz Dolby Atmos Tuned by AKG |
| Active noise cancellation | 4 microphones | 3 microphones |
| Radio | Not supported | FM |
| TV | Not supported | Not supported |
| Video formats | MP4, H.265, H.264, H.263, XviD, MKV | MP4, H.265, H.264, H.263, XviD, MKV |
| Audio formats | MP3, WAV, WMA, eAAC+, FLAC | MP3, WAV, WMA, eAAC+, FLAC |
🔌 Connectivity | ||
| Xiaomi 15 (China 512GB/12GB) | Galaxy S21 Ultra (SM-G998U1 512GB) | |
| USB | USB 3.2 Type-C, USB OTG On-The-Go | USB 3.2 Type-C, USB OTG On-The-Go |
| Audio output | Type-C reversible connector | Type-C reversible connector |
| TV output | USB Type-C (reversible) | USB Type-C (reversible) |
| Bluetooth | 6.0 + A2DP/LE | 5.2 + A2DP/LE |
| WiFi | 802.11 a/b/g/n/ac/ax/be [wifi7/6E/6] (2.4GHz, 5GHz, 6GHz) + MIMO WiFi Direct, hotspot | 802.11 a/b/g/n/ac/ax [wifi6] (2.4GHz, 5GHz) + MIMO WiFi Direct, hotspot |
| DLNA | Not supported | Supported |
| GPS | A-GPS, GeoTagging, GLONASS, GALILEO, BeiDou, QZSS | A-GPS, GeoTagging, GLONASS, GALILEO, BeiDou |
| NFC | Supported | Supported |
| Infrared port | Supported | Not supported |
🧭 Sensors | ||
| Xiaomi 15 (China 512GB/12GB) | Galaxy S21 Ultra (SM-G998U1 512GB) | |
| Sensors | Accelerometer Ambient light sensor Barometer Compass Face unlock Fingerprint sensor (under display) Gyroscope Proximity sensor | Accelerometer Ambient light sensor Barometer Compass Face unlock Fingerprint sensor (under display) Gesture Gyroscope Hall effect Proximity sensor UWB (Ultra Wideband) |
| Vibrating alert | Supported | Supported |
🔋 Battery | ||
| Xiaomi 15 (China 512GB/12GB) | Galaxy S21 Ultra (SM-G998U1 512GB) | |
| Battery type | Li-Si: lithium-silicon (Non removable) | LiPo: li-ion polymer (Non removable) |
| Battery capacity | 5400 mAh | 5000 mAh |
| Charger, watts | 90W Wired fast charging Reverse charging by cable Quick Charge 3+ USB Power Delivery 3.0 | 25W Wired fast charging USB Power Delivery 3.0 |
| Inductive / wireless charging | 50W Qi Wireless charging (Qi/WPC) 10W Reverse wireless charging | 15W Qi wireless charging (Qi/PMA) 4.5W Reverse wireless charging |
| Talk time autonomy | feature not registered | feature not registered |
| Standby | feature not registered | feature not registered |
➕ Other features | ||
| Xiaomi 15 (China 512GB/12GB) | Galaxy S21 Ultra (SM-G998U1 512GB) | |
| Call control | Voice dialing, Voice recorder, Voice commands | Voice dialing, Voice recorder, Voice commands |
| Messaging | SMS (T9), MMS, E-mail, Push mail | SMS (T9), MMS, E-mail, Push mail |
| Hands-free calling | Supported | Supported |
| Video calling | Supported | Supported |
| Ringtones | Polyphonic and customized | Polyphonic and customized |
| Web browser | HTML, XHTML, HTML5 | HTML, XHTML, HTML5 |
| Antenna | Internal antenna | Internal antenna |
| Qwerty physical keyboard | Not supported | Not supported |
| Miscellaneous | • Colors: Black, White, Green, Lilac, Liquid Silver • Xiaomi HyperAI | • Colors: Phantom Black, Silver, Titanium, Navy, Brown • Samsung Pay (Visa, MasterCard) • Samsung DeX • Stylus pen support |
☢️ Radiation rate | ||
| Xiaomi 15 (China 512GB/12GB) | Galaxy S21 Ultra (SM-G998U1 512GB) | |
| SAR 1.6W/kg (USA, Mexico, etc.) | feature not registered | 0.77W/kg (head), 1.02W/kg (body) |
| SAR 2W/kg (Europe, UK, etc.) | 0.99W/kg (head), 1W/kg (body) | feature not registered |