Samsung Galaxy S21 Ultra (SM-G998U1 128GB) vs Samsung Galaxy A55 (SM-A556E/DS 128GB)
Side by side comparison between Samsung Galaxy S21 Ultra vs Samsung Galaxy A55 phones, differences, pros, cons and full specifications. What's the better?
,
6.8"
AMOLED
AMOLED
1440x3200
108
MP
MP
40mp
12GB
RAM
RAM
Octa-core
5000
mAh
mAh
(Non removable)
vs
6.6"
AMOLED
AMOLED
1080x2340
50
MP
MP
32mp
8GB
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!
17 Advantages 
5 Advantages | 40 Common items in both devices |
| 128GB (101GB available) / 128GB (109GB available) |
| UFS 3.1 |
| Aluminum frame, glass front/back |
| Dynamic AMOLED / Super AMOLED |
| HDR10+ |
| 120Hz |
| 16 million |
| +33 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-G998U1 128GB) | Galaxy A55 (SM-A556E/DS 128GB) | |
| Model | Galaxy S21 Ultra (SM-G998U1 128GB) | Galaxy A55 (SM-A556E/DS 128GB) |
| Other model names | Galaxy S21 Ultra 5G (SM-G998U1) Unlocked | Galaxy A55 5G SM-A556E/Dual-SIM |
| Country or region available |  USA |   (Latin America), Brazil |
| Brand | Samsung | Samsung |
| Release date | 1/29/2021, Announced: 1/14/2021 | 3/15/2024, Announced: 3/11/2024 |
| 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) | 77.4 x 161.1 millimeters (3.05 x 6.34 in) |
| Weight | 227 grams (7.95 ounces) | 213 grams (7.46 ounces) |
| Build, materials | Aluminum frame, glass front/back | Aluminum frame, glass front/back Back: Corning Gorilla Glass |
| Protection against water and others | IP68 certified: water-resistant up to 1.5 meters for 30min and dust-resistant | IP67 certified: dust proof and waterproof over 1 meter and 30min |
📲 Display | ||
| Galaxy S21 Ultra (SM-G998U1 128GB) | Galaxy A55 (SM-A556E/DS 128GB) | |
| Display type | Dynamic AMOLED | Super AMOLED |
| Screen size | 6.8" inches | 6.6" inches |
| Screen-to-body ratio | ~89.4% (screen-to-body ratio) | ~85.8% (screen-to-body ratio) |
| Display resolution | 1440x3200 pixels (20:9) | 1080x2340 pixels (19.5:9) |
| Touchscreen | Capacitive Multitouch 10-points | Capacitive Multitouch |
| Pixel density (dot pitch) | 516 PPI | 390 PPI |
| Colors | 16 million | 16 million |
| Scratch-resistant glass | Gorilla Glass Victus | Gorilla Glass Victus |
| Refresh rate | 120Hz | 120Hz |
| Display features | 1500nits[peak] HDR10+ Always-On Display | HDR10+ Always-On Display |
🤖 Operating System | ||
| Galaxy S21 Ultra (SM-G998U1 128GB) | Galaxy A55 (SM-A556E/DS 128GB) | |
| System version | Android 11 | Android 14 |
| Firmware update | Android 14 | feature not registered |
| User Interface | One UI 3.1 / 4.1 / 5.1 / 6.0 | One UI 6.1 |
⚙️ Processor | ||
| Galaxy S21 Ultra (SM-G998U1 128GB) | Galaxy A55 (SM-A556E/DS 128GB) | |
| Chipset | 64bit: Qualcomm Snapdragon 888 (SM8350) (5nm) | 64bit: Samsung Exynos 1480 (4nm) |
| CPU | 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) | Octa-core, 2 processors: 4x 2.75GHz ARM Cortex-A78 (Quad-core) 4x 2GHz ARM Cortex-A55 (Quad-core) |
| GPU graphical controller | Qualcomm Adreno 660 (840MHz) | Samsung Xclipse 530 |
| Performance (benchmark) | AnTuTu: 681099 (v8), 809165 (v9) Geekbench: 3539 (v5.2) GFXBench: 54fps (ES 3.1 onscreen) | AnTuTu: 635598 (v9), 726158 (v10) Geekbench: 3259 (v5), 3350 (v6) |
💽 Memory and storage | ||
| Galaxy S21 Ultra (SM-G998U1 128GB) | Galaxy A55 (SM-A556E/DS 128GB) | |
| RAM memory | 12GB LPDDR5 | 8GB LPDDR5 |
| Internal storage | 128GB (101GB available) UFS 3.1 | 128GB (109GB available) UFS 3.1 |
| External storage | Not supported | Until 1TB microSD, microSDXC (hybrid slot/shares the same SIM-2 slot) |
📶 Mobile networks | ||
| Galaxy S21 Ultra (SM-G998U1 128GB) | Galaxy A55 (SM-A556E/DS 128GB) | |
| Dual-SIM | Dual-SIM Standby - Call active on one sim card | Dual-SIM Standby - Call active on one sim card (hybrid slot/shares the same microSD slot) |
| SIM card | 1 slot (Single-SIM) nano-SIM (4FF) + e-SIM | 1 slot (Single-SIM) nano-SIM (4FF) + e-SIM |
| Maximum Download / Upload | 5000/1920 Mbps | 3000/1024 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 | CDMA 800/1900, GSM 850/900/1800/1900 | GSM 850/900/1800/1900 |
| Primary 3G network | CDMA2000 1xEV-DO UMTS 850/900/1700/1900/2100 | UMTS 850/900/1700/1900/2100 |
| Primary 4G network | 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 | LTE Cat18 (1, 2, 3, 4, 5, 7, 8, 12, 13, 17, 20, 25, 26, 28, 66) TD-LTE (38, 40, 41) VoLTE |
| Primary 5G network | SA/NSA/Sub6 (2, 5, 25, 41, 66, 71) mmWave (260, 261) | SA/NSA/Sub6 (1, 3, 5, 7, 8, 26, 28, 40, 41, 66, 77, 78) |
| Primary data network | GPRS, EDGE, CDMA2000 EV-DO Rev 0, CDMA2000 EV-DO Rev A, UMTS, HSDPA, HSUPA, HSPA+, TD-LTE, LTE, LTE-A, SA/NSA, Sub6 | GPRS, EDGE, UMTS, HSDPA, HSUPA, HSPA+, TD-LTE, LTE, LTE-A, SA/NSA, Sub6 |
| Secondary 2G network | CDMA 800/1900, GSM 850/900/1800/1900 | Not supported |
| Secondary 3G network | CDMA2000 1xEV-DO UMTS 850/900/1700/1900/2100 | Not supported |
| Secondary 4G network | 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 | Not supported |
| Secondary data network | GPRS, EDGE, CDMA2000 EV-DO Rev 0, CDMA2000 EV-DO Rev A, UMTS, HSDPA, HSUPA, HSPA+, TD-LTE, LTE, LTE-A, SA/NSA, Sub6 | Not supported |
📷 Camera | ||
| Galaxy S21 Ultra (SM-G998U1 128GB) | Galaxy A55 (SM-A556E/DS 128GB) | |
| 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 | (triple camera) 50 megapixels 12MP ultrawide f/2.2123°1/3.06"1.12µm 5MP macro f/2.4 |
| Main camera resolution | 12000x9000 pixels | 8160x6120 pixels |
| Video recording (primary) | 8K UHD (7680x4320) 24 fps | 4K UHD (3840x2160) 30 fps |
| Flash | LED flash | LED flash |
| Focal aperture | f/1.8 (aperture) | f/1.8 (aperture) |
| Focal length | 26mm (lens) | feature not registered |
| Sensor size | 1/1.33" inches | 1/1.56" inches |
| Pixel size | 1.8µm pixel | 1µm pixel |
| Autofocus | PDAF: phase detection autofocus on both cameras | PDAF: phase detection autofocus |
| Touch focus | Supported | Supported |
| Image stabilization | OIS: Optical stabilization | OIS: Optical stabilization |
| Zoom | Digital and optical zoom | Only digital 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 on both cameras |
| Camera extras | 4K@60fps 1080p@240fps 720p@960fps | 4K@30fps 1080p@30/60fps 720p@240fps (slow motion) |
📸 Front camera | ||
| Galaxy S21 Ultra (SM-G998U1 128GB) | Galaxy A55 (SM-A556E/DS 128GB) | |
| Front camera (secondary) | 40 megapixels | 32 megapixels |
| Front camera resolution | 7296x5472 pixels | 6528x4896 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 | 1/2.74" inches |
| Pixel size | 0.7µm pixel | 0.8µm pixel |
🔉 Sound and multimedia | ||
| Galaxy S21 Ultra (SM-G998U1 128GB) | Galaxy A55 (SM-A556E/DS 128GB) | |
| Loudspeaker | Stereo sound 32-bit/384kHz Dolby Atmos Tuned by AKG | Stereo sound |
| Active noise cancellation | 3 microphones | 2 microphones or more |
| 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-G998U1 128GB) | Galaxy A55 (SM-A556E/DS 128GB) | |
| USB | USB 3.2 Type-C, USB OTG On-The-Go | USB 2.0 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 | 5.3 + 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 [wifi6] (2.4GHz, 5GHz) + MIMO WiFi Direct, hotspot |
| DLNA | Supported | Not 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-G998U1 128GB) | Galaxy A55 (SM-A556E/DS 128GB) | |
| 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 Compass Face unlock Fingerprint sensor (under display) Gyroscope Hall effect Virtual proximity sensor |
| Vibrating alert | Supported | Supported |
🔋 Battery | ||
| Galaxy S21 Ultra (SM-G998U1 128GB) | Galaxy A55 (SM-A556E/DS 128GB) | |
| 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 | 25W Wired fast charging |
| Inductive / wireless charging | 15W Qi wireless charging (Qi/PMA) 4.5W Reverse wireless charging | Not supported |
| Talk time autonomy | feature not registered | feature not registered |
| Standby | feature not registered | feature not registered |
➕ Other features | ||
| Galaxy S21 Ultra (SM-G998U1 128GB) | Galaxy A55 (SM-A556E/DS 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: Phantom Black, Silver, Titanium, Navy, Brown • Samsung Pay (Visa, MasterCard) • Samsung DeX • Stylus pen support | • Colors: Navy, Iceblue, Lilac, Lemon |
☢️ Radiation rate | ||
| Galaxy S21 Ultra (SM-G998U1 128GB) | Galaxy A55 (SM-A556E/DS 128GB) | |
| SAR 1.6W/kg (USA, Mexico, etc.) | 0.77W/kg (head), 1.02W/kg (body) | feature not registered |
| SAR 2W/kg (Europe, UK, etc.) | feature not registered | feature not registered |