Asus Zenfone 2 (ZE551ML 32GB) vs Samsung Galaxy S21
Side by side comparison between Asus Zenfone 2 vs Samsung Galaxy S21 phones, differences, pros, cons and full specifications. What's the better?
,
5.5"
IPS
IPS
1080x1920
13
MP
MP
5mp
4GB
RAM
RAM
Quad-core
3000
mAh
mAh
(Non removable)
vs
6.2"
AMOLED
AMOLED
1080x2400
12.2
MP
MP
10mp
8GB
RAM
RAM
Octa-core
4000
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!
3 Advantages 
30 Advantages | 15 Common items in both devices |
| 16 million |
| Autofocus / PDAF: phase detection autofocus on both cameras |
| Capacitive |
| Multitouch |
| Accelerometer |
| Ambient light sensor |
| Compass |
| +8 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 | ||
| Asus Zenfone 2 (ZE551ML 32GB) | Galaxy S21 | |
| Model | Zenfone 2 (ZE551ML 32GB) | Galaxy S21 |
| Other model names | Asus Zenfone 2 ZE551ML Dual-sim (32GB + 4GB RAM) | Galaxy S21 5G SM-G991B/DS |
| Country or region available | feature not registered |  (Global, International) |
| Brand | Asus | Samsung |
| Release date | 3/1/2015 | 1/29/2021, Announced: 1/14/2021 |
| Depth | 10.9 millimeters (0.43 inches) | 7.9 millimeters (0.31 inches) |
| Size (width x height) | 77.2 x 152.5 millimeters (3.04 x 6 in) | 71.2 x 151.7 millimeters (2.8 x 5.97 in) |
| Weight | 170 grams (5.95 ounces) | 169 grams (5.92 ounces) |
| Build, materials | feature not registered | Aluminum body, glass front, plastic back |
| Protection against water and others | Not supported | IP68 certified: water-resistant up to 1.5 meters for 30min and dust-resistant |
📲 Display | ||
| Asus Zenfone 2 (ZE551ML 32GB) | Galaxy S21 | |
| Display type | TFT IPS LCD | Dynamic AMOLED |
| Screen size | 5.5" inches | 6.2" inches |
| Screen-to-body ratio | ~70.8% (screen-to-body ratio) | ~85.9% (screen-to-body ratio) |
| Display resolution | 1080x1920 pixels | 1080x2400 pixels (20:9) |
| Touchscreen | Capacitive Multitouch | Capacitive Multitouch 10-points |
| Pixel density (dot pitch) | 401 PPI | 424 PPI |
| Colors | 16 million | 16 million |
| Scratch-resistant glass | Gorilla Glass 3 | Gorilla Glass Victus |
| Refresh rate | feature not registered | 120Hz |
| Display features | feature not registered | 1300nits[peak] HDR10+ Always-On Display |
🤖 Operating System | ||
| Asus Zenfone 2 (ZE551ML 32GB) | Galaxy S21 | |
| System version | Android 5.0 Lollipop | Android 11 |
| Firmware update | Android 6.0 Marshmallow | Android 14 |
| User Interface | feature not registered | One UI 3.1 / 4.1 / 5.1 / 6.0 |
⚙️ Processor | ||
| Asus Zenfone 2 (ZE551ML 32GB) | Galaxy S21 | |
| Chipset | 64bit: Intel Atom Z3580 | 64bit: Samsung Exynos 2100 (5nm) |
| CPU | Quad-core, 1 processor: 4x 2.3GHz Intel Silvermont (Quad-core) | 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) |
| GPU graphical controller | PowerVR G6430 MP4 | ARM Mali-G78 MP14 (854MHz) |
| Performance (benchmark) | feature not registered | feature not registered |
💽 Memory and storage | ||
| Asus Zenfone 2 (ZE551ML 32GB) | Galaxy S21 | |
| RAM memory | 4GB LPDDR3 | 8GB LPDDR5 |
| Internal storage | 32GB (28GB available) | 128GB (104GB available) UFS 3.1 |
| External storage | Until 64GB microSD, microSDXC (dedicated slot) | Not supported |
📶 Mobile networks | ||
| Asus Zenfone 2 (ZE551ML 32GB) | Galaxy S21 | |
| Dual-SIM | Dual-SIM Standby - Call active on one sim card (dedicated slot) | Dual-SIM Standby - Call active on one sim card |
| SIM card | 2 slots (Dual-SIM) micro-SIM (3FF) | 2 slots (Dual-SIM) nano-SIM (4FF) + e-SIM |
| Maximum Download / Upload | 150/50 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 850/900/1900/2100 | CDMA2000 1xEV-DO TD-SCDMA 1900/2000 UMTS 850/900/1700/1900/2100 |
| Primary 4G network | LTE Cat4 800/850/900/1700/1800/1900/2100/2600 Bands (1,2,3,4,5,7,8,20) - USA: 700/800/850/900/1700/1800/1900/2100/2600 (Bands 1,2,3,4,5,7,8,17,20) | LTE Cat24 () TD-LTE () VoLTE |
| Primary 5G network | Not supported | SA/NSA/Sub6 () |
| Primary data network | GPRS, EDGE, UMTS, HSDPA, HSUPA, HSPA+, LTE | 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 | GSM 850/900/1800/1900 | GSM 850/900/1800/1900 |
| Secondary 3G network | Not supported | UMTS 850/900/1700/1900/2100 |
| Secondary 4G network | Not supported | LTE Cat24 () TD-LTE () VoLTE |
| Secondary data network | GPRS, EDGE | GPRS, EDGE, UMTS, HSDPA, HSUPA, HSPA+, TD-LTE, LTE, LTE-A |
📷 Camera | ||
| Asus Zenfone 2 (ZE551ML 32GB) | Galaxy S21 | |
| Back camera (main camera) | 13 megapixels | (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 |
| Main camera resolution | 4128x3096 pixels | 4032x3024 pixels |
| Video recording (primary) | Full HD (1920x1080) 30 fps | 8K UHD (7680x4320) 24 fps |
| Flash | Dual-LED flash | LED flash |
| Focal aperture | f/2.0 (aperture) | f/1.8 (aperture) |
| Focal length | feature not registered | 26mm lens |
| Sensor size | feature not registered | 1/1.76" inches |
| Pixel size | feature not registered | 1.8µm pixel |
| Autofocus | Autofocus | PDAF: phase detection autofocus on both cameras |
| Touch focus | Supported | Supported |
| Image stabilization | feature not registered | OIS: Optical stabilization |
| Zoom | Only digital zoom | Digital and optical zoom |
| Face/smile detection | Face detection, Smile detection | Face detection, Smile detection |
| BSI sensor | Not supported | Supported |
| HDR | HDR photo only main camera | HDR photo/video on both cameras |
| Camera extras | feature not registered | 4K@60fps 1080p@240fps 720p@960fps |
📸 Front camera | ||
| Asus Zenfone 2 (ZE551ML 32GB) | Galaxy S21 | |
| Front camera (secondary) | 5 megapixels | 10 megapixels |
| Front camera resolution | 2560x1920 pixels | 3872x2592 pixels |
| Video recording (secondary) | HD (1280x720) | 4K UHD (3840x2160) |
| Front flash | Not supported | Not supported |
| Focal aperture | feature not registered | f/2.2 (aperture) |
| Focal length | feature not registered | 26mm lens |
| Sensor size | feature not registered | 1/3.24" inches |
| Pixel size | feature not registered | 1.22µm pixel |
🔉 Sound and multimedia | ||
| Asus Zenfone 2 (ZE551ML 32GB) | Galaxy S21 | |
| Loudspeaker | Supported | Stereo sound 32-bit/384kHz Dolby Atmos Tuned by AKG |
| Active noise cancellation | Not supported | 2 microphones or more |
| Radio | FM (RDS) | FM |
| TV | Not supported | Not supported |
| Video formats | MP4, H.264, H.263 | MP4, H.265, H.264, H.263, XviD, MKV |
| Audio formats | MP3, WAV, eAAC+ | MP3, WAV, WMA, eAAC+, FLAC |
🔌 Connectivity | ||
| Asus Zenfone 2 (ZE551ML 32GB) | Galaxy S21 | |
| USB | MicroUSB 2.0 | 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 | 4.0 + A2DP | 5.0 + A2DP/LE |
| WiFi | 802.11 a/b/g/n/ac [wifi5] (2.4GHz, 5GHz) WiFi Direct, hotspot | 802.11 a/b/g/n/ac/ax [wifi6] (2.4GHz, 5GHz) + MIMO WiFi Direct, hotspot |
| DLNA | Not supported | Supported |
| GPS | A-GPS, GeoTagging, GLONASS | A-GPS, GeoTagging, GLONASS, GALILEO, BeiDou |
| NFC | Supported | Supported |
| Infrared port | Not supported | Not supported |
🧭 Sensors | ||
| Asus Zenfone 2 (ZE551ML 32GB) | Galaxy S21 | |
| Sensors | Accelerometer Ambient light sensor Compass Gyroscope Proximity sensor | Accelerometer Ambient light sensor Barometer Compass Face unlock Fingerprint sensor (under display) Gesture Gyroscope Hall effect Proximity sensor |
| Vibrating alert | Supported | Supported |
🔋 Battery | ||
| Asus Zenfone 2 (ZE551ML 32GB) | Galaxy S21 | |
| Battery type | LiPo: li-ion polymer (Non removable) | LiPo: li-ion polymer (Non removable) |
| Battery capacity | 3000 mAh | 4000 mAh |
| Charger, watts | Wired charging | 25W Wired fast charging USB Power Delivery 3.0 |
| Inductive / wireless charging | feature not registered | 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 | ||
| Asus Zenfone 2 (ZE551ML 32GB) | Galaxy S21 | |
| Call control | Voice dialing, Voice recorder | 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, Gold, Gray, Red, White • Asus ZenUI • Fast battery charging: 60% in 40min • 5GB free ASUS WebStorage • OpenGL 3.0 • Asus BoostMaster 18W adapter included | • Colors: Phantom Gray, White, Violet, Pink • Samsung Pay (Visa, MasterCard) • Samsung DeX |
☢️ Radiation rate | ||
| Asus Zenfone 2 (ZE551ML 32GB) | Galaxy S21 | |
| SAR 1.6W/kg (USA, Mexico, etc.) | feature not registered | feature not registered |
| SAR 2W/kg (Europe, UK, etc.) | feature not registered | 0.456W/kg (head), 1.509W/kg (body) |