Samsung Galaxy S21 Ultra (SM-G998N 512GB) vs Samsung Galaxy S25 Ultra (SM-S938B/DS 256GB)
Side by side comparison between Samsung Galaxy S21 Ultra vs Samsung Galaxy S25 Ultra phones, differences, pros, cons and full specifications. What's the better?
,
6.8"
AMOLED
AMOLED
1440x3200
108
MP
MP
40mp
16GB
RAM
RAM
Octa-core
5000
mAh
mAh
(Non removable)
vs
6.9"
AMOLED
AMOLED
1440x3120
200
MP
MP
12mp
12GB
RAM
RAM
Octa-core
5000
mAh
mAh
(Non removable)
What's the better phone? Samsung Galaxy S25 Ultra (SM-S938B/DS 256GB)
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!
6 Advantages 
14 Advantages | 41 Common items in both devices |
| Dynamic AMOLED / LTPO AMOLED |
| HDR10+ |
| 120Hz |
| 16 million |
| LED flash |
| Digital and optical zoom |
| PDAF: phase detection autofocus on both cameras |
| +34 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 | ||
| Galaxy S21 Ultra (SM-G998N 512GB) | Galaxy S25 Ultra (SM-S938B/DS 256GB) | |
| Model | Galaxy S21 Ultra (SM-G998N 512GB) | Galaxy S25 Ultra (SM-S938B/DS 256GB) |
| Other model names | 갤럭시 S21 Ultra 5G (SM-G998N Single-SIM) | Galaxy S25 Ultra SM-S938B/Dual-SIM |
| Country or region available |  South Korea |  (Global, International) |
| Brand | Samsung | Samsung |
| Release date | 1/29/2021, Announced: 1/14/2021 | 2/3/2025, Announced: 2/22/2025 |
| Depth | 8.9 millimeters (0.35 inches) | 8.2 millimeters (0.32 inches) |
| Size (width x height) | 75.6 x 165.1 millimeters (2.98 x 6.5 in) | 77.6 x 162.8 millimeters (3.06 x 6.41 in) |
| Weight | 227 grams (7.95 ounces) | 218 grams (7.63 ounces) |
| Build, materials | Aluminum frame, glass front/back | Titanium frame, glass front and back Back: Gorilla Armor 2 |
| 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 | ||
| Galaxy S21 Ultra (SM-G998N 512GB) | Galaxy S25 Ultra (SM-S938B/DS 256GB) | |
| Display type | Dynamic AMOLED | LTPO AMOLED |
| Screen size | 6.8" inches | 6.9" inches |
| Screen-to-body ratio | ~89.4% (screen-to-body ratio) | ~92.5% (screen-to-body ratio) |
| Display resolution | 1440x3200 pixels (20:9) | 1440x3120 pixels (19.5:9) |
| Touchscreen | Capacitive Multitouch 10-points | Capacitive Multitouch 10-points |
| Pixel density (dot pitch) | 516 PPI | 498 PPI |
| Colors | 16 million | 16 million |
| Scratch-resistant glass | Gorilla Glass Victus | Gorilla Armor 2 |
| Refresh rate | 120Hz | 120Hz |
| Display features | 1500nits[peak] HDR10+ Always-On Display | 2600nits[peak] HDR10+ Always-On Display |
🤖 Operating System | ||
| Galaxy S21 Ultra (SM-G998N 512GB) | Galaxy S25 Ultra (SM-S938B/DS 256GB) | |
| System version | Android 11 | Android 15 |
| Firmware update | Android 14 | feature not registered |
| User Interface | One UI 3.1 / 4.1 / 5.1 / 6.0 | One UI 7.0 |
⚙️ Processor | ||
| Galaxy S21 Ultra (SM-G998N 512GB) | Galaxy S25 Ultra (SM-S938B/DS 256GB) | |
| Chipset | 64bit: Samsung Exynos 2100 (5nm) | 64bit: Qualcomm Snapdragon 8 Elite (SM8750-AB) (3nm) |
| CPU | Octa-core, 3 processors: 1x 2.9GHz ARM Cortex-X1 (Single-core) 3x 2.8GHz ARM Cortex-A78 (Triple-core) 4x 2.2GHz ARM Cortex-A55 (Quad-core) | Octa-core, 2 processors: 2x 4.47GHz Oryon V2 Phoenix L (Dual-core) 6x 3.53GHz Oryon V2 Phoenix M (Hexa-core) |
| GPU graphical controller | ARM Mali-G78 MP14 (854MHz) | Qualcomm Adreno 830 (1100MHz) |
| Performance (benchmark) | AnTuTu: 657150 (v8), 727634 (v9) Geekbench: 3457 (v5.2) GFXBench: 51fps (ES 3.1 onscreen) | AnTuTu: 2207809 (v10) Geekbench: 9846 (v6) |
💽 Memory and storage | ||
| Galaxy S21 Ultra (SM-G998N 512GB) | Galaxy S25 Ultra (SM-S938B/DS 256GB) | |
| RAM memory | 16GB LPDDR5 | 12GB LPDDR5X |
| Internal storage | 512GB (457GB available) UFS 3.1 | 256GB (223GB available) UFS 4.0 |
| External storage | Not supported | Not supported |
📶 Mobile networks | ||
| Galaxy S21 Ultra (SM-G998N 512GB) | Galaxy S25 Ultra (SM-S938B/DS 256GB) | |
| Dual-SIM | Not supported | Dual-SIM Standby - Call active on one sim card |
| SIM card | 1 slot (Single-SIM) nano-SIM (4FF) | 2 slots (Dual-SIM) nano-SIM (4FF) + e-SIM |
| Maximum Download / Upload | 5000/1920 Mbps | 5000/1024 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 TD-SCDMA 1900/2000 UMTS |
| Primary 4G network | LTE Cat20 (1, 2, 3, 4, 5, 7, 8, 12, 13, 17, 18, 19, 20, 25, 26, 28, 66) TD-LTE (38, 39, 40, 41) VoLTE | LTE Cat24 () TD-LTE () VoLTE |
| Primary 5G network | SA/NSA/Sub6 (77, 78) | SA/NSA/Sub6 () |
| Primary data network | GPRS, EDGE, UMTS, HSDPA, HSUPA, HSPA+, TD-LTE, LTE, LTE-A, SA/NSA | GPRS, EDGE, CDMA2000 EV-DO Rev 0, CDMA2000 EV-DO Rev A, TD-SCDMA, UMTS, TD-HSDPA, HSDPA, HSUPA, HSPA+, TD-LTE, LTE, LTE-A, SA/NSA, Sub6 |
| Secondary 2G network | Not supported | CDMA 800/1900, GSM 850/900/1800/1900 |
| Secondary 3G network | Not supported | CDMA2000 1xEV-DO TD-SCDMA 1900/2000 UMTS |
| Secondary 4G network | Not supported | LTE Cat24 () TD-LTE () VoLTE |
| Secondary data network | Not supported | GPRS, EDGE, CDMA2000 EV-DO Rev 0, CDMA2000 EV-DO Rev A, TD-SCDMA, UMTS, TD-HSDPA, HSDPA, HSUPA, HSPA+, TD-LTE, LTE, LTE-A, SA/NSA, Sub6 |
📷 Camera | ||
| Galaxy S21 Ultra (SM-G998N 512GB) | Galaxy S25 Ultra (SM-S938B/DS 256GB) | |
| Back camera (main camera) | (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 | (quad camera) 200 megapixels 10MP telephoto f/2.467mm1/3.52"1.12µmPDAFOIS3x-optical-zoom 50MP periscope telephoto f/3.4111mm1/2.52"0.7µmPDAFOIS5x-optical-zoom 50MP ultrawide f/1.9120°0.7µmPDAFSuper-Steady |
| Main camera resolution | 12000x9000 pixels | 20000x10000 pixels |
| Video recording (primary) | 8K UHD (7680x4320) 24 fps | 8K UHD (7680x4320) 30 fps |
| Flash | LED flash | LED flash |
| Focal aperture | f/1.8 (aperture) | f/1.7 (aperture) |
| Focal length | 26mm (lens) | 24mm (lens) |
| Sensor size | 1/1.33" inches | 1/1.3" inches |
| Pixel size | 1.8µm pixel | 0.6µm pixel |
| Autofocus | PDAF: phase detection autofocus on both cameras | 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 | 4K@60fps 1080p@240fps 720p@960fps | feature not registered |
📸 Front camera | ||
| Galaxy S21 Ultra (SM-G998N 512GB) | Galaxy S25 Ultra (SM-S938B/DS 256GB) | |
| Front camera (secondary) | 40 megapixels | 12 megapixels |
| Front camera resolution | 7296x5472 pixels | 4000x3000 pixels |
| Video recording (secondary) | 4K UHD (3840x2160) | 4K UHD (3840x2160) |
| Front flash | Not supported | Not supported |
| Focal aperture | f/2.2 (aperture) | f/2.2 (aperture) |
| Focal length | 26mm (lens) | 26mm (lens) |
| Sensor size | 1/2.8" inches | 1/3.2" inches |
| Pixel size | 0.7µm pixel | 1.12µm pixel |
🔉 Sound and multimedia | ||
| Galaxy S21 Ultra (SM-G998N 512GB) | Galaxy S25 Ultra (SM-S938B/DS 256GB) | |
| Loudspeaker | Stereo sound 32-bit/384kHz Dolby Atmos Tuned by AKG | Stereo sound 32-bit/384kHz Tuned by AKG |
| Active noise cancellation | 3 microphones | 3 microphones |
| Radio | FM | Not supported |
| 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 | ||
| Galaxy S21 Ultra (SM-G998N 512GB) | Galaxy S25 Ultra (SM-S938B/DS 256GB) | |
| 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 | 5.2 + A2DP/LE | 5.4 + A2DP/LE |
| WiFi | 802.11 a/b/g/n/ac/ax [wifi6] (2.4GHz, 5GHz) + MIMO WiFi Direct, hotspot | 802.11 a/b/g/n/ac/ax/be [wifi7/6E/6] (2.4GHz, 5GHz, 6GHz) + MIMO WiFi Direct, hotspot |
| DLNA | Supported | Supported |
| GPS | A-GPS, GeoTagging, GLONASS, GALILEO, BeiDou | A-GPS, GeoTagging, GLONASS, GALILEO, BeiDou, QZSS |
| NFC | Supported | Supported |
| Infrared port | Not supported | Not supported |
🧭 Sensors | ||
| Galaxy S21 Ultra (SM-G998N 512GB) | Galaxy S25 Ultra (SM-S938B/DS 256GB) | |
| Sensors | Accelerometer Ambient light sensor Barometer Compass Face unlock Fingerprint sensor (under display) Gesture Gyroscope Hall effect Proximity sensor UWB (Ultra Wideband) | Accelerometer Ambient light sensor Barometer Compass Face unlock Fingerprint sensor (under display) Gyroscope Hall effect Proximity sensor UWB (Ultra Wideband) |
| Vibrating alert | Supported | Supported |
🔋 Battery | ||
| Galaxy S21 Ultra (SM-G998N 512GB) | Galaxy S25 Ultra (SM-S938B/DS 256GB) | |
| Battery type | LiPo: li-ion polymer (Non removable) | Li-Ion: lithium-ion (Non removable) |
| Battery capacity | 5000 mAh | 5000 mAh |
| Charger, watts | 25W Wired fast charging USB Power Delivery 3.0 | 45W Wired fast charging Reverse charging by cable USB Power Delivery 3.0 |
| Inductive / wireless charging | 15W Qi wireless charging (Qi/PMA) 4.5W Reverse wireless charging | 15W Qi wireless charging 4.5W Reverse wireless charging |
| Talk time autonomy | feature not registered | feature not registered |
| Standby | feature not registered | feature not registered |
➕ Other features | ||
| Galaxy S21 Ultra (SM-G998N 512GB) | Galaxy S25 Ultra (SM-S938B/DS 256GB) | |
| 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: Phantom Black, Silver, Titanium, Navy, Brown • Samsung Pay (Visa, MasterCard) • Samsung DeX • Stylus pen support | • Samsung DeX • Samsung Wireless DeX • Stylus (S Pen) • Circle to Search |
☢️ Radiation rate | ||
| Galaxy S21 Ultra (SM-G998N 512GB) | Galaxy S25 Ultra (SM-S938B/DS 256GB) | |
| SAR 1.6W/kg (USA, Mexico, etc.) | 0.489W/kg (head), 1.1W/kg (body) | feature not registered |
| SAR 2W/kg (Europe, UK, etc.) | feature not registered | feature not registered |