Samsung Galaxy S6 (SM-G920T) vs Samsung Galaxy S21 Ultra (SM-G998U1 128GB)
Side by side comparison between Samsung Galaxy S6 vs Samsung Galaxy S21 Ultra phones, differences, pros, cons and full specifications. What's the better?
,
5.1"
AMOLED
AMOLED
1440x2560
16
MP
MP
5mp
3GB
RAM
RAM
Octa-core
2550
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 S21 Ultra (SM-G998U1 128GB)
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!
7 Advantages 
27 Advantages | 23 Common items in both devices |
| Aluminum frame, glass front/back |
| Super AMOLED / Dynamic AMOLED |
| 16 million |
| LED flash |
| Autofocus / PDAF: phase detection autofocus on both cameras |
| OIS: Optical stabilization |
| HDR photo/video on both cameras |
| +16 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 S6 (SM-G920T) | Galaxy S21 Ultra (SM-G998U1 128GB) | |
| Model | Galaxy S6 (SM-G920T) | Galaxy S21 Ultra (SM-G998U1 128GB) |
| Other model names | T-Mobile Galaxy S6 G920T, Samsung Zero F | Galaxy S21 Ultra 5G (SM-G998U1) Unlocked |
| Country or region available |  USA | USA |
| Brand | Samsung | Samsung |
| Release date | 4/10/2015 | 1/29/2021, Announced: 1/14/2021 |
| Depth | 6.8 millimeters (0.27 inches) | 8.9 millimeters (0.35 inches) |
| Size (width x height) | 70.5 x 143.4 millimeters (2.78 x 5.65 in) | 75.6 x 165.1 millimeters (2.98 x 6.5 in) |
| Weight | 138 grams (4.83 ounces) | 227 grams (7.95 ounces) |
| Build, materials | Aluminum frame, glass front/back | Aluminum frame, glass front/back |
| Protection against water and others | Not supported | IP68 certified: water-resistant up to 1.5 meters for 30min and dust-resistant |
📲 Display | ||
| Galaxy S6 (SM-G920T) | Galaxy S21 Ultra (SM-G998U1 128GB) | |
| Display type | Super AMOLED | Dynamic AMOLED |
| Screen size | 5.1" inches | 6.8" inches |
| Screen-to-body ratio | ~70.9% (screen-to-body ratio) | ~89.4% (screen-to-body ratio) |
| Display resolution | 1440x2560 pixels | 1440x3200 pixels (20:9) |
| Touchscreen | Capacitive Multitouch 10-points | Capacitive Multitouch 10-points |
| Pixel density (dot pitch) | 576 PPI | 516 PPI |
| Colors | 16 million | 16 million |
| Scratch-resistant glass | Gorilla Glass 4 | Gorilla Glass Victus |
| Refresh rate | feature not registered | 120Hz |
| Display features | feature not registered | 1500nits[peak] HDR10+ Always-On Display |
🤖 Operating System | ||
| Galaxy S6 (SM-G920T) | Galaxy S21 Ultra (SM-G998U1 128GB) | |
| System version | Android 5.0.2 Lollipop | Android 11 |
| Firmware update | Android 8.0 Oreo | Android 14 |
| User Interface | feature not registered | One UI 3.1 / 4.1 / 5.1 / 6.0 |
⚙️ Processor | ||
| Galaxy S6 (SM-G920T) | Galaxy S21 Ultra (SM-G998U1 128GB) | |
| Chipset | 64bit: Samsung Exynos 7 Octa 7420 (14nm) | 64bit: Qualcomm Snapdragon 888 (SM8350) (5nm) |
| CPU | Octa-core, 2 processors: 4x 2.1GHz ARM Cortex-A57 (Quad-core) 4x 1.5GHz ARM Cortex-A53 (Quad-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 | ARM Mali-T760 MP8 | Qualcomm Adreno 660 (840MHz) |
| Performance (benchmark) | feature not registered | AnTuTu: 681099 (v8), 809165 (v9) Geekbench: 3539 (v5.2) GFXBench: 54fps (ES 3.1 onscreen) |
💽 Memory and storage | ||
| Galaxy S6 (SM-G920T) | Galaxy S21 Ultra (SM-G998U1 128GB) | |
| RAM memory | 3GB LPDDR4 | 12GB LPDDR5 |
| Internal storage | 64GB (54GB available) UFS 2.0 | 128GB (101GB available) UFS 3.1 |
| External storage | Not supported | Not supported |
📶 Mobile networks | ||
| Galaxy S6 (SM-G920T) | Galaxy S21 Ultra (SM-G998U1 128GB) | |
| Dual-SIM | Not supported | Dual-SIM Standby - Call active on one sim card |
| SIM card | 1 slot (Single-SIM) nano-SIM (4FF) | 1 slot (Single-SIM) nano-SIM (4FF) + e-SIM |
| Maximum Download / Upload | 300/50 Mbps | 5000/1920 Mbps |
| Network technology | 2G, 3G, 4G | 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 850/1700/1900/2100 | CDMA2000 1xEV-DO UMTS 850/900/1700/1900/2100 |
| Primary 4G network | LTE Cat6 (Bands 1, 2, 3, 4, 5, 7, 12, 17, 20) | 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 | Not supported | SA/NSA/Sub6 (2, 5, 25, 41, 66, 71) mmWave (260, 261) |
| Primary data network | GPRS, EDGE, UMTS, HSDPA, HSUPA, HSPA+, LTE, LTE-A | 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 | Not supported | CDMA 800/1900, GSM 850/900/1800/1900 |
| Secondary 3G network | Not supported | CDMA2000 1xEV-DO UMTS 850/900/1700/1900/2100 |
| Secondary 4G network | Not supported | 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 | Not supported | 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 | ||
| Galaxy S6 (SM-G920T) | Galaxy S21 Ultra (SM-G998U1 128GB) | |
| Back camera (main camera) | 16 megapixels | (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 | 5312x2988 pixels | 12000x9000 pixels |
| Video recording (primary) | 4K UHD (3840x2160) 30 fps | 8K UHD (7680x4320) 24 fps |
| Flash | LED flash | LED flash |
| Focal aperture | f/1.9 (aperture) | f/1.8 (aperture) |
| Focal length | 28mm lens | 26mm lens |
| Sensor size | 1/2.6" inches | 1/1.33" inches |
| Pixel size | 1.12µm pixel | 1.8µm pixel |
| Autofocus | Autofocus | PDAF: phase detection autofocus on both cameras |
| Touch focus | Supported | Supported |
| Image stabilization | OIS: Optical stabilization | OIS: Optical stabilization |
| Zoom | Only digital 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 S6 (SM-G920T) | Galaxy S21 Ultra (SM-G998U1 128GB) | |
| Front camera (secondary) | 5 megapixels | 40 megapixels |
| Front camera resolution | 2592x1944 pixels | 7296x5472 pixels |
| Video recording (secondary) | 2K UHD (2560x1440) | 4K UHD (3840x2160) |
| Front flash | Not supported | Not supported |
| Focal aperture | f/1.9 (aperture) | f/2.2 (aperture) |
| Focal length | 22mm lens | 26mm lens |
| Sensor size | 1/4.1" inches | 1/2.8" inches |
| Pixel size | 1.34µm pixel | 0.7µm pixel |
🔉 Sound and multimedia | ||
| Galaxy S6 (SM-G920T) | Galaxy S21 Ultra (SM-G998U1 128GB) | |
| Loudspeaker | Supported | Stereo sound 32-bit/384kHz Dolby Atmos Tuned by AKG |
| Active noise cancellation | 2 microphones or more | 2 microphones or more |
| Radio | Not supported | FM |
| TV | Not supported | Not supported |
| Video formats | MP4, H.264, H.263, DivX, XviD, WMV | MP4, H.265, H.264, H.263, XviD, MKV |
| Audio formats | MP3, WAV, WMA, eAAC+, FLAC | MP3, WAV, WMA, eAAC+, FLAC |
🔌 Connectivity | ||
| Galaxy S6 (SM-G920T) | Galaxy S21 Ultra (SM-G998U1 128GB) | |
| USB | MicroUSB 2.0, USB OTG On-The-Go | USB 3.2 Type-C, USB OTG On-The-Go |
| Audio output | 3.5mm jack | Type-C reversible connector |
| TV output | Not supported | USB Type-C (reversible) |
| Bluetooth | 4.1 + A2DP | 5.2 + A2DP/LE |
| WiFi | 802.11 a/b/g/n/ac [wifi5] (2.4GHz, 5GHz) + 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, BeiDou | A-GPS, GeoTagging, GLONASS, GALILEO, BeiDou |
| NFC | Supported | Supported |
| Infrared port | Supported | Not supported |
🧭 Sensors | ||
| Galaxy S6 (SM-G920T) | Galaxy S21 Ultra (SM-G998U1 128GB) | |
| Sensors | Accelerometer Ambient light sensor ANT+ Barometer Compass Fingerprint sensor (front-mounted) Gyroscope Hall effect Heart rate Proximity sensor SpO2 | 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 S6 (SM-G920T) | Galaxy S21 Ultra (SM-G998U1 128GB) | |
| Battery type | Li-Ion: lithium-ion (Non removable) | LiPo: li-ion polymer (Non removable) |
| Battery capacity | 2550 mAh | 5000 mAh |
| Charger, watts | 15W Wired fast charging | 25W Wired fast charging USB Power Delivery 3.0 |
| Inductive / wireless charging | Qi wireless charging (Qi/PMA) | 15W Qi wireless charging (Qi/PMA) 4.5W Reverse wireless charging |
| Talk time autonomy | 17 hours | feature not registered |
| Standby | feature not registered | feature not registered |
➕ Other features | ||
| Galaxy S6 (SM-G920T) | Galaxy S21 Ultra (SM-G998U1 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 | • Colors: Black, Blue, White, Gold • Gorilla Glass 4 back panel • Samsung Pay (Visa, MasterCard certified) • S-Voice natural language • OneDrive 115GB • ANT+ | • Colors: Phantom Black, Silver, Titanium, Navy, Brown • Samsung Pay (Visa, MasterCard) • Samsung DeX • Stylus pen support |
☢️ Radiation rate | ||
| Galaxy S6 (SM-G920T) | Galaxy S21 Ultra (SM-G998U1 128GB) | |
| SAR 1.6W/kg (USA, Mexico, etc.) | 0.64W/kg (head), 1.31W/kg (body) | 0.77W/kg (head), 1.02W/kg (body) |
| SAR 2W/kg (Europe, UK, etc.) | 0.289W/kg (head), 0.54W/kg (body) | feature not registered |