Samsung Galaxy S21 vs Samsung Galaxy M55 (SM-M556E/DS 128GB)
Side by side comparison between Samsung Galaxy S21 vs Samsung Galaxy M55 phones, differences, pros, cons and full specifications. What's the better?
,
6.2"
AMOLED
AMOLED
1080x2400
12.2
MP
MP
10mp
8GB
RAM
RAM
Octa-core
4000
mAh
mAh
(Non removable)
vs
6.7"
AMOLED
AMOLED
1080x2400
50
MP
MP
50mp
8GB
RAM
RAM
Octa-core
5000
mAh
mAh
(Non removable)
What's the better phone? Samsung Galaxy S21
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!
18 Advantages 
9 Advantages | 34 Common items in both devices |
| 128GB (104GB available) / 128GB (105GB available) |
| Dynamic AMOLED / Super AMOLED |
| 120Hz |
| 16 million |
| 1080x2400 pixels |
| LED flash |
| PDAF: phase detection autofocus on both cameras / PDAF: phase detection autofocus |
| +27 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 | Galaxy M55 (SM-M556E/DS 128GB) | |
| Change model | ||
| Model | Galaxy S21 | Galaxy M55 (SM-M556E/DS 128GB) |
| Other model names | Galaxy S21 5G SM-G991B/DS | Galaxy M55 5G SM-M556E/Dual-SIM |
| Country or region available |  (Global, International) |   (Europe), Russia |
| Brand | Samsung | Samsung |
| Release date | 1/29/2021, Announced: 1/14/2021 | 3/28/2024 |
| Depth | 7.9 millimeters (0.31 inches) | 7.8 millimeters (0.31 inches) |
| Size (width x height) | 71.2 x 151.7 millimeters (2.8 x 5.97 in) | 76.5 x 163.9 millimeters (3.01 x 6.45 in) |
| Weight | 169 grams (5.92 ounces) | 180 grams (6.3 ounces) |
| Build, materials | Aluminum body, glass front, plastic back | Plastic body, glass front |
| Protection against water and others | IP68 certified: water-resistant up to 1.5 meters for 30min and dust-resistant | Not supported |
📲 Display | ||
| Galaxy S21 | Galaxy M55 (SM-M556E/DS 128GB) | |
| Display type | Dynamic AMOLED | Super AMOLED |
| Screen size | 6.2" inches | 6.7" inches |
| Screen-to-body ratio | ~85.9% (screen-to-body ratio) | ~86.4% (screen-to-body ratio) |
| Display resolution | 1080x2400 pixels (20:9) | 1080x2400 pixels (20:9) |
| Touchscreen | Capacitive Multitouch 10-points | Capacitive Multitouch 10-points |
| Pixel density (dot pitch) | 424 PPI | 393 PPI |
| Colors | 16 million | 16 million |
| Scratch-resistant glass | Gorilla Glass Victus | Not supported |
| Refresh rate | 120Hz | 120Hz |
| Display features | 1300nits[peak] HDR10+ Always-On Display | Always-On Display |
🤖 Operating System | ||
| Galaxy S21 | Galaxy M55 (SM-M556E/DS 128GB) | |
| System version | Android 11 | Android 14 |
| Firmware update | Android 15 | Android 15 |
| User Interface | One UI 3.1 / 4.1 / 5.1 / 6.0 / 7.0 | One UI 6.1 / 7.0 |
⚙️ Processor | ||
| Galaxy S21 | Galaxy M55 (SM-M556E/DS 128GB) | |
| Chipset | 64bit: Samsung Exynos 2100 (5nm) | 64bit: Qualcomm Snapdragon 7 Gen 1 (SM7450-AB) (4nm) |
| 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, 3 processors: 1x 2.4GHz ARM Cortex-A710 (Single-core) 3x 2.36GHz ARM Cortex-A710 (Triple-core) 4x 1.8GHz ARM Cortex-A510 (Quad-core) |
| GPU graphical controller | ARM Mali-G78 MP14 (854MHz) | Qualcomm Adreno 644 (443MHz) |
| Performance (benchmark) | feature not registered | AnTuTu: 582102 (v10) |
💽 Memory and storage | ||
| Galaxy S21 | Galaxy M55 (SM-M556E/DS 128GB) | |
| RAM memory | 8GB LPDDR5 | 8GB LPDDR4X |
| Internal storage | 128GB (104GB available) UFS 3.1 | 128GB (105GB available) UFS 2.2 |
| External storage | Not supported | Until 1TB microSD, microSDXC (hybrid slot/shares the same SIM-2 slot) |
📶 Mobile networks | ||
| Galaxy S21 | Galaxy M55 (SM-M556E/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 | 2 slots (Dual-SIM) nano-SIM (4FF) + e-SIM | 2 slots (Dual-SIM) nano-SIM (4FF) |
| 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 TD-SCDMA 1900/2000 UMTS 850/900/1700/1900/2100 | UMTS 850/900/1700/1900/2100 |
| Primary 4G network | LTE Cat24 () TD-LTE () VoLTE | LTE Cat18 (1, 2, 3, 4, 5, 7, 8, 12, 17, 20, 25, 26, 28, 66) TD-LTE (38, 40, 41) VoLTE |
| Primary 5G network | SA/NSA/Sub6 () | SA/NSA/Sub6 (1, 3, 5, 7, 8, 20, 28, 38, 40, 41, 66, 77, 78) |
| 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, Sub6 |
| Secondary 2G network | GSM 850/900/1800/1900 | GSM 850/900/1800/1900 |
| Secondary 3G network | UMTS 850/900/1700/1900/2100 | UMTS 850/900/1700/1900/2100 |
| Secondary 4G network | LTE Cat24 () TD-LTE () VoLTE | LTE Cat18 (1, 2, 3, 4, 5, 7, 8, 12, 17, 20, 25, 26, 28, 66) TD-LTE (38, 40, 41) VoLTE |
| Secondary data network | GPRS, EDGE, UMTS, HSDPA, HSUPA, HSPA+, TD-LTE, LTE, LTE-A | GPRS, EDGE, UMTS, HSDPA, HSUPA, HSPA+, TD-LTE, LTE, LTE-A, SA/NSA, Sub6 |
📷 Camera | ||
| Galaxy S21 | Galaxy M55 (SM-M556E/DS 128GB) | |
| Back camera (main camera) | (triple camera) 12.2 megapixels 64MP telephoto f/2.029mm1/1.72"0.8µmPDAFOIS1.1x-optical-zoom3x-hybrid-zoom 12MP ultrawide f/2.213mm120°1/2.55"1.4µmSuper-Steady-video | (triple camera) 50 megapixels 8MP ultrawide f/2.2123° 2MP macro f/2.4 |
| Main camera resolution | 4032x3024 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 | 1/1.76" 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 | Galaxy M55 (SM-M556E/DS 128GB) | |
| Front camera (secondary) | 10 megapixels | 50 megapixels |
| Front camera resolution | 3872x2592 pixels | 8160x6120 pixels |
| Video recording (secondary) | 4K UHD (3840x2160) | 4K UHD (3840x2160) |
| Front flash | Not supported | Not supported |
| Focal aperture | f/2.2 (aperture) | f/2.4 (aperture) |
| Focal length | 26mm (lens) | feature not registered |
| Sensor size | 1/3.24" inches | feature not registered |
| Pixel size | 1.22µm pixel | feature not registered |
🔉 Sound and multimedia | ||
| Galaxy S21 | Galaxy M55 (SM-M556E/DS 128GB) | |
| Loudspeaker | Stereo sound 32-bit/384kHz Dolby Atmos Tuned by AKG | Stereo sound |
| Active noise cancellation | 2 microphones | 2 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 | Galaxy M55 (SM-M556E/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 | 5.0 + A2DP/LE | 5.2 + 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 | Galaxy M55 (SM-M556E/DS 128GB) | |
| Sensors | Accelerometer Ambient light sensor Barometer Compass Face unlock 2D Fingerprint sensor (under display) Gesture Gyroscope Hall effect Proximity sensor | Accelerometer Ambient light sensor Compass Face unlock 2D Fingerprint sensor (under display) Gyroscope Proximity sensor |
| Vibrating alert | Supported | Supported |
🔋 Battery | ||
| Galaxy S21 | Galaxy M55 (SM-M556E/DS 128GB) | |
| Battery type | LiPo: li-ion polymer (Non removable) | Li-Ion: lithium-ion (Non removable) |
| Battery capacity | 4000 mAh | 5000 mAh |
| Charger, watts | 25W Wired fast charging USB Power Delivery 3.0 | 45W 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 | Galaxy M55 (SM-M556E/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 Gray, White, Violet, Pink • Samsung Pay (Visa, MasterCard) • Samsung DeX | • Colors: Dark Blue, Light Green |
☢️ Radiation rate | ||
| Galaxy S21 | Galaxy M55 (SM-M556E/DS 128GB) | |
| SAR 1.6W/kg (USA, Mexico, etc.) | feature not registered | feature not registered |
| SAR 2W/kg (Europe, UK, etc.) | 0.456W/kg (head), 1.509W/kg (body) | 0.81W/kg (head), 1.18W/kg (body) |