Samsung Galaxy S25 Ultra (SM-S938B/DS 256GB) vs Samsung Galaxy S21 Ultra (SM-G998W 128GB)
Side by side comparison between Samsung Galaxy S25 Ultra vs Samsung Galaxy S21 Ultra phones, differences, pros, cons and full specifications. What's the better?
,
6.9"
AMOLED
AMOLED
1440x3120
200
MP
MP
12mp
12GB
RAM
RAM
Octa-core
5000
mAh
mAh
(Non removable)
vs
6.8"
AMOLED
AMOLED
1440x3200
108
MP
MP
40mp
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!
14 Advantages 
4 Advantages | 43 Common items in both devices |
| 12GB LPDDR5X / 12GB LPDDR5 |
| LTPO AMOLED / Dynamic AMOLED |
| HDR10+ |
| 120Hz |
| 16 million |
| LED flash |
| Digital and optical zoom |
| +36 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 S25 Ultra (SM-S938B/DS 256GB) | Galaxy S21 Ultra (SM-G998W 128GB) | |
| Change model | ||
| Model | Galaxy S25 Ultra (SM-S938B/DS 256GB) | Galaxy S21 Ultra (SM-G998W 128GB) |
| Other model names | Galaxy S25 Ultra SM-S938B/Dual-SIM | Galaxy S21 Ultra 5G (SM-G998W) |
| Country or region available |  (Global, International) |  Canada |
| Brand | Samsung | Samsung |
| Release date | 2/3/2025, Announced: 2/22/2025 | 1/29/2021, Announced: 1/14/2021 |
| Depth | 8.2 millimeters (0.32 inches) | 8.9 millimeters (0.35 inches) |
| Size (width x height) | 77.6 x 162.8 millimeters (3.06 x 6.41 in) | 75.6 x 165.1 millimeters (2.98 x 6.5 in) |
| Weight | 218 grams (7.63 ounces) | 227 grams (7.95 ounces) |
| Build, materials | Titanium frame, glass front and back Back: Gorilla Armor 2 | 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 | ||
| Galaxy S25 Ultra (SM-S938B/DS 256GB) | Galaxy S21 Ultra (SM-G998W 128GB) | |
| Display type | LTPO AMOLED | Dynamic AMOLED |
| Screen size | 6.9" inches | 6.8" inches |
| Screen-to-body ratio | ~92.5% (screen-to-body ratio) | ~89.4% (screen-to-body ratio) |
| Display resolution | 1440x3120 pixels (19.5:9) | 1440x3200 pixels (20:9) |
| Touchscreen | Capacitive Multitouch 10-points | Capacitive Multitouch 10-points |
| Pixel density (dot pitch) | 498 PPI | 516 PPI |
| Colors | 16 million | 16 million |
| Scratch-resistant glass | Gorilla Armor 2 | Gorilla Glass Victus |
| Refresh rate | 120Hz | 120Hz |
| Display features | 2600nits[peak] HDR10+ Always-On Display | 1500nits[peak] HDR10+ Always-On Display |
🤖 Operating System | ||
| Galaxy S25 Ultra (SM-S938B/DS 256GB) | Galaxy S21 Ultra (SM-G998W 128GB) | |
| System version | Android 15 | Android 11 |
| Firmware update | feature not registered | Android 14 |
| User Interface | One UI 7.0 | One UI 3.1 / 4.1 / 5.1 / 6.0 |
⚙️ Processor | ||
| Galaxy S25 Ultra (SM-S938B/DS 256GB) | Galaxy S21 Ultra (SM-G998W 128GB) | |
| Chipset | 64bit: Qualcomm Snapdragon 8 Elite (SM8750-AB) (3nm) | 64bit: Qualcomm Snapdragon 888 (SM8350) (5nm) |
| CPU | Octa-core, 2 processors: 2x 4.47GHz 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: 2207809 (v10) Geekbench: 9846 (v6) | AnTuTu: 681099 (v8), 809165 (v9) Geekbench: 3539 (v5.2) GFXBench: 54fps (ES 3.1 onscreen) |
💽 Memory and storage | ||
| Galaxy S25 Ultra (SM-S938B/DS 256GB) | Galaxy S21 Ultra (SM-G998W 128GB) | |
| RAM memory | 12GB LPDDR5X | 12GB LPDDR5 |
| Internal storage | 256GB (223GB available) UFS 4.0 | 128GB (101GB available) UFS 3.1 |
| External storage | Not supported | Not supported |
📶 Mobile networks | ||
| Galaxy S25 Ultra (SM-S938B/DS 256GB) | Galaxy S21 Ultra (SM-G998W 128GB) | |
| 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 | 5000/1024 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 | CDMA 800/1900, GSM 850/900/1800/1900 | GSM 850/900/1800/1900 |
| Primary 3G network | CDMA2000 1xEV-DO TD-SCDMA 1900/2000 UMTS | UMTS 850/900/1700/1900/2100 |
| Primary 4G network | LTE Cat24 () TD-LTE () VoLTE | LTE Cat20 (1, 2, 3, 4, 5, 7, 8, 12, 13, 18, 19, 20, 25, 29, 30, 66, 71) TD-LTE (38, 39, 40, 41, 46) VoLTE |
| Primary 5G network | SA/NSA/Sub6 () | SA/NSA/Sub6 (2, 41, 66, 71) |
| Primary data network | 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 | GPRS, EDGE, UMTS, HSDPA, HSUPA, HSPA+, TD-LTE, LTE, LTE-A, SA/NSA |
| Secondary 2G network | CDMA 800/1900, GSM 850/900/1800/1900 | GSM 850/900/1800/1900 |
| Secondary 3G network | CDMA2000 1xEV-DO TD-SCDMA 1900/2000 UMTS | UMTS 850/900/1700/1900/2100 |
| Secondary 4G network | LTE Cat24 () TD-LTE () VoLTE | LTE Cat20 (1, 2, 3, 4, 5, 7, 8, 12, 13, 18, 19, 20, 25, 29, 30, 66, 71) TD-LTE (38, 39, 40, 41, 46) VoLTE |
| Secondary data network | 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 | GPRS, EDGE, UMTS, HSDPA, HSUPA, HSPA+, TD-LTE, LTE, LTE-A, SA/NSA |
📷 Camera | ||
| Galaxy S25 Ultra (SM-S938B/DS 256GB) | Galaxy S21 Ultra (SM-G998W 128GB) | |
| Back camera (main camera) | (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 | (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 | 20000x10000 pixels | 12000x9000 pixels |
| Video recording (primary) | 8K UHD (7680x4320) 30 fps | 8K UHD (7680x4320) 24 fps |
| Flash | LED flash | LED flash |
| Focal aperture | f/1.7 (aperture) | f/1.8 (aperture) |
| Focal length | 24mm (lens) | 26mm (lens) |
| Sensor size | 1/1.3" inches | 1/1.33" inches |
| Pixel size | 0.6µm pixel | 1.8µm 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 | feature not registered | 4K@60fps 1080p@240fps 720p@960fps |
📸 Front camera | ||
| Galaxy S25 Ultra (SM-S938B/DS 256GB) | Galaxy S21 Ultra (SM-G998W 128GB) | |
| Front camera (secondary) | 12 megapixels | 40 megapixels |
| Front camera resolution | 4000x3000 pixels | 7296x5472 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 | 1/3.2" inches | 1/2.8" inches |
| Pixel size | 1.12µm pixel | 0.7µm pixel |
🔉 Sound and multimedia | ||
| Galaxy S25 Ultra (SM-S938B/DS 256GB) | Galaxy S21 Ultra (SM-G998W 128GB) | |
| Loudspeaker | Stereo sound 32-bit/384kHz Tuned by AKG | Stereo sound 32-bit/384kHz Dolby Atmos Tuned by AKG |
| Active noise cancellation | 3 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 | ||
| Galaxy S25 Ultra (SM-S938B/DS 256GB) | Galaxy S21 Ultra (SM-G998W 128GB) | |
| 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 | 5.4 + 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 | Supported | Supported |
| GPS | A-GPS, GeoTagging, GLONASS, GALILEO, BeiDou, QZSS | A-GPS, GeoTagging, GLONASS, GALILEO, BeiDou |
| NFC | Supported | Supported |
| Infrared port | Not supported | Not supported |
🧭 Sensors | ||
| Galaxy S25 Ultra (SM-S938B/DS 256GB) | Galaxy S21 Ultra (SM-G998W 128GB) | |
| Sensors | Accelerometer Ambient light sensor Barometer Compass Face unlock Fingerprint sensor (under display) Gyroscope Hall effect Proximity sensor UWB (Ultra Wideband) | 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 | ||
| Galaxy S25 Ultra (SM-S938B/DS 256GB) | Galaxy S21 Ultra (SM-G998W 128GB) | |
| Battery type | Li-Ion: lithium-ion (Non removable) | LiPo: li-ion polymer (Non removable) |
| Battery capacity | 5000 mAh | 5000 mAh |
| Charger, watts | 45W Wired fast charging Reverse charging by cable USB Power Delivery 3.0 | 25W Wired fast charging USB Power Delivery 3.0 |
| Inductive / wireless charging | 15W Qi wireless charging 4.5W 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 | ||
| Galaxy S25 Ultra (SM-S938B/DS 256GB) | Galaxy S21 Ultra (SM-G998W 128GB) | |
| 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 | • Samsung DeX • Samsung Wireless DeX • Stylus (S Pen) • Circle to Search | • Colors: Phantom Black, Silver, Titanium, Navy, Brown • Samsung Pay (Visa, MasterCard) • Samsung DeX • Stylus pen support |
☢️ Radiation rate | ||
| Galaxy S25 Ultra (SM-S938B/DS 256GB) | Galaxy S21 Ultra (SM-G998W 128GB) | |
| SAR 1.6W/kg (USA, Mexico, etc.) | feature not registered | 1.12W/kg (head), 1.25W/kg (body) |
| SAR 2W/kg (Europe, UK, etc.) | feature not registered | feature not registered |