Samsung Galaxy Z Flip 4 (SM-F721W 128GB) vs Samsung Galaxy S21
Side by side comparison between Samsung Galaxy Z Flip 4 vs Samsung Galaxy S21 phones, differences, pros, cons and full specifications. What's the better?
,
6.7"
AMOLED
AMOLED
1080x2640
12.2
MP
MP
10mp
8GB
RAM
RAM
Octa-core
3700
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!
6 Advantages 
9 Advantages | 45 Common items in both devices |
| 8GB LPDDR5 |
| 128GB (99GB available) / 128GB (104GB available) |
| UFS 3.1 |
| Aluminum frame, flexible plastic screen, glass back / Aluminum body, glass front, plastic back |
| Dynamic AMOLED |
| HDR10+ |
| 120Hz |
| +38 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 Z Flip 4 (SM-F721W 128GB) | Galaxy S21 | |
| Model | Galaxy Z Flip 4 (SM-F721W 128GB) | Galaxy S21 |
| Other model names | Galaxy Z Flip4 5G (SM-F721W) | Galaxy S21 5G SM-G991B/DS |
| Country or region available |  Canada |  (Global, International) |
| Brand | Samsung | Samsung |
| Release date | 8/25/2022, Announced: 8/10/2022 | 1/29/2021, Announced: 1/14/2021 |
| Depth | 6.9 millimeters (0.27 inches) | 7.9 millimeters (0.31 inches) |
| Size (width x height) | 71.9 x 165.2 millimeters (2.83 x 6.5 in) | 71.2 x 151.7 millimeters (2.8 x 5.97 in) |
| Weight | 187 grams (6.55 ounces) | 169 grams (5.92 ounces) |
| Build, materials | Aluminum frame, flexible plastic screen, glass back Back: Gorilla Glass Victus+ Folded: 15.9 x 71.9 x 84.9 mm | Aluminum body, glass front, plastic back |
| Protection against water and others | IPX8 certified: water resistant up to 1.5 meters and 30min | IP68 certified: water-resistant up to 1.5 meters for 30min and dust-resistant |
📲 Display | ||
| Galaxy Z Flip 4 (SM-F721W 128GB) | Galaxy S21 | |
| Display type | Dynamic AMOLED | Dynamic AMOLED |
| Screen size | 6.7" inches | 6.2" inches |
| Screen-to-body ratio | ~85.4% (screen-to-body ratio) | ~85.9% (screen-to-body ratio) |
| Display resolution | 1080x2640 pixels | 1080x2400 pixels (20:9) |
| Touchscreen | Capacitive Multitouch | Capacitive Multitouch 10-points |
| Pixel density (dot pitch) | 426 PPI | 424 PPI |
| Colors | 16 million | 16 million |
| Scratch-resistant glass | Not supported | Gorilla Glass Victus |
| Refresh rate | 120Hz | 120Hz |
| Display features | 1200nits[peak] HDR10+ Always-On Display Extra display: Super AMOLED 1.9" (260x512), Gorilla Glass Victus+ | 1300nits[peak] HDR10+ Always-On Display |
🤖 Operating System | ||
| Galaxy Z Flip 4 (SM-F721W 128GB) | Galaxy S21 | |
| System version | Android 12 | Android 11 |
| Firmware update | Android 15 | Android 15 |
| User Interface | One UI 4.1 / 5.1 / 6.0 / 7.0 | One UI 3.1 / 4.1 / 5.1 / 6.0 / 7.0 |
⚙️ Processor | ||
| Galaxy Z Flip 4 (SM-F721W 128GB) | Galaxy S21 | |
| Chipset | 64bit: Qualcomm Snapdragon 8+ Gen 1 (SM8475) (4nm) | 64bit: Samsung Exynos 2100 (5nm) |
| CPU | Octa-core, 3 processors: 1x 3.19GHz ARM Cortex-X2 (Single-core) 3x 2.75GHz ARM Cortex-A710 (Triple-core) 4x 2GHz ARM Cortex-A510 (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 | Qualcomm Adreno 730 (818MHz) | ARM Mali-G78 MP14 (854MHz) |
| Performance (benchmark) | AnTuTu: 685765 (v8), 800001 (v9) Geekbench: 3913 (v5.1) GFXBench: 74fps (ES 3.1 onscreen) | feature not registered |
💽 Memory and storage | ||
| Galaxy Z Flip 4 (SM-F721W 128GB) | Galaxy S21 | |
| RAM memory | 8GB LPDDR5 | 8GB LPDDR5 |
| Internal storage | 128GB (99GB available) UFS 3.1 | 128GB (104GB available) UFS 3.1 |
| External storage | Not supported | Not supported |
📶 Mobile networks | ||
| Galaxy Z Flip 4 (SM-F721W 128GB) | Galaxy S21 | |
| Dual-SIM | Dual-SIM Standby - Call active on one sim card | Dual-SIM Standby - Call active on one sim card |
| SIM card | 1 slot (Single-SIM) nano-SIM (4FF) + e-SIM | 2 slots (Dual-SIM) nano-SIM (4FF) + e-SIM |
| Maximum Download / Upload | 3000/1024 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 | GSM 850/900/1800/1900 | CDMA 800/1900, GSM 850/900/1800/1900 |
| Primary 3G network | UMTS 850/900/1700/1900/2100 | CDMA2000 1xEV-DO TD-SCDMA 1900/2000 UMTS 850/900/1700/1900/2100 |
| Primary 4G network | 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 | LTE Cat24 () TD-LTE () VoLTE |
| Primary 5G network | SA/NSA/Sub6 (2, 5, 38, 41, 66, 71, 78) | SA/NSA/Sub6 () |
| Primary data network | GPRS, EDGE, UMTS, HSDPA, HSUPA, HSPA+, TD-LTE, LTE, LTE-A, SA/NSA, Sub6 | 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 | UMTS 850/900/1700/1900/2100 | UMTS 850/900/1700/1900/2100 |
| Secondary 4G network | 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 | LTE Cat24 () TD-LTE () VoLTE |
| Secondary data network | GPRS, EDGE, UMTS, HSDPA, HSUPA, HSPA+, TD-LTE, LTE, LTE-A, SA/NSA, Sub6 | GPRS, EDGE, UMTS, HSDPA, HSUPA, HSPA+, TD-LTE, LTE, LTE-A |
📷 Camera | ||
| Galaxy Z Flip 4 (SM-F721W 128GB) | Galaxy S21 | |
| Back camera (main camera) | (dual camera) 12.2 megapixels 12MP ultrawide f/2.2123°1.12µm | (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 | 4032x3024 pixels | 4032x3024 pixels |
| Video recording (primary) | 4K UHD (3840x2160) 60 fps | 8K UHD (7680x4320) 24 fps |
| Flash | LED flash | LED flash |
| Focal aperture | f/1.8 (aperture) | f/1.8 (aperture) |
| Focal length | 24mm (lens) | 26mm (lens) |
| Sensor size | 1/1.76" inches | 1/1.76" inches |
| Pixel size | 1.8µm pixel | 1.8µm pixel |
| Autofocus | PDAF: phase detection 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 | 4K@30/60fps 1080p@30/60/240fps 720p@960fps HDR10+ Slow motion | 4K@60fps 1080p@240fps 720p@960fps |
📸 Front camera | ||
| Galaxy Z Flip 4 (SM-F721W 128GB) | Galaxy S21 | |
| Front camera (secondary) | 10 megapixels | 10 megapixels |
| Front camera resolution | 3872x2592 pixels | 3872x2592 pixels |
| Video recording (secondary) | 4K UHD (3840x2160) | 4K UHD (3840x2160) |
| Front flash | Not supported | Not supported |
| Focal aperture | f/2.4 (aperture) | f/2.2 (aperture) |
| Focal length | 26mm (lens) | 26mm (lens) |
| Sensor size | 1/3" inches | 1/3.24" inches |
| Pixel size | 1.22µm pixel | 1.22µm pixel |
🔉 Sound and multimedia | ||
| Galaxy Z Flip 4 (SM-F721W 128GB) | Galaxy S21 | |
| Loudspeaker | Stereo sound 32-bit/384kHz Dolby Atmos Tuned by AKG | Stereo sound 32-bit/384kHz Dolby Atmos Tuned by AKG |
| Active noise cancellation | 2 microphones or more | 2 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 Z Flip 4 (SM-F721W 128GB) | Galaxy S21 | |
| USB | USB 2.0 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 | 5.2 + A2DP/LE | 5.0 + 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 | Supported |
| GPS | A-GPS, GeoTagging, GLONASS, GALILEO, BeiDou | A-GPS, GeoTagging, GLONASS, GALILEO, BeiDou |
| NFC | Supported | Supported |
| Infrared port | Not supported | Not supported |
🧭 Sensors | ||
| Galaxy Z Flip 4 (SM-F721W 128GB) | Galaxy S21 | |
| Sensors | Accelerometer Ambient light sensor Barometer Compass Face unlock 2D Fingerprint sensor (side-mounted) Gyroscope Hall effect Proximity sensor | Accelerometer Ambient light sensor Barometer Compass Face unlock 2D Fingerprint sensor (under display) Gesture Gyroscope Hall effect Proximity sensor |
| Vibrating alert | Supported | Supported |
🔋 Battery | ||
| Galaxy Z Flip 4 (SM-F721W 128GB) | Galaxy S21 | |
| Battery type | LiPo: li-ion polymer (Non removable) | LiPo: li-ion polymer (Non removable) |
| Battery capacity | 3700 mAh | 4000 mAh |
| Charger, watts | 25W 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 (Qi/WPC) 4.5W Reverse wireless charging | 15W Qi wireless charging (Qi/PMA) 4.5W Reverse wireless charging |
| Talk time autonomy | 34 hours (1.4 days) | feature not registered |
| Standby | feature not registered | feature not registered |
➕ Other features | ||
| Galaxy Z Flip 4 (SM-F721W 128GB) | Galaxy S21 | |
| 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: Graphite, White, Bora Purple, Pink Gold, Blue, Yellow, Navy, Khaki, Red • Samsung Pay (Visa, MasterCard) | • Colors: Phantom Gray, White, Violet, Pink • Samsung Pay (Visa, MasterCard) • Samsung DeX |
☢️ Radiation rate | ||
| Galaxy Z Flip 4 (SM-F721W 128GB) | Galaxy S21 | |
| SAR 1.6W/kg (USA, Mexico, etc.) | 1.02W/kg (head), 0.94W/kg (body) | feature not registered |
| SAR 2W/kg (Europe, UK, etc.) | feature not registered | 0.456W/kg (head), 1.509W/kg (body) |