Samsung Galaxy Z Fold3 5G vs. S21 Ultra 5G: A Deep Dive Comparison

The Samsung Galaxy Z Fold3 5G represents a bold step into the future of mobile, offering a foldable experience unlike any other. However, the Galaxy S21 Ultra 5G remains a formidable contender, packing a top-tier camera system and exceptional battery life into a more conventional, yet refined, package. This comparison dissects the core differences between these two Samsung flagships, helping you determine which best suits your needs and budget.
Phones Images

🏆 Quick Verdict

For the average user prioritizing battery life and a more robust, traditional smartphone experience, the Samsung Galaxy S21 Ultra 5G is the clear winner. Its significantly longer endurance rating (114h vs 75h) and brighter display outweigh the Z Fold3’s innovative form factor for most daily tasks.

PHONES
Phone Names Samsung Galaxy Z Fold3 5G Samsung Galaxy S21 Ultra 5G
Network
2G bandsGSM 850 / 900 / 1800 / 1900GSM 850 / 900 / 1800 / 1900
3G bandsHSDPA 850 / 900 / 1700(AWS) / 1900 / 2100HSDPA 850 / 900 / 1700(AWS) / 1900 / 2100
4G bands1, 2, 3, 4, 5, 7, 8, 12, 13, 17, 18, 19, 20, 25, 26, 28, 32, 38, 39, 40, 41, 46, 48, 66 - Europe1, 2, 3, 4, 5, 7, 8, 12, 13, 14, 18, 19, 20, 25, 26, 28, 30, 38, 39, 40, 41, 46, 48, 66, 71 - SM-G998U1
5G bands1, 3, 5, 7, 8, 20, 28, 38, 40, 41, 66, 77, 78 SA/NSA/Sub6 - International2, 5, 25, 41, 66, 71, 260, 261 SA/NSA/Sub6/mmWave - SM-G998U1
SpeedHSPA 42.2/5.76 Mbps, LTE (7CA) Cat20 2000/200 Mbps, 5GHSPA 42.2/5.76 Mbps, LTE (7CA) Cat20 2000/200 Mbps, 5G (5+ Gbps DL)
TechnologyGSM / CDMA / HSPA / EVDO / LTE / 5GGSM / CDMA / HSPA / EVDO / LTE / 5G
 2, 5, 25, 41, 66, 71, 78, 260, 261 SA/NSA/Sub6/mmWave - USA1, 3, 5, 7, 8, 20, 28, 38, 40, 41, 66, 77, 78 SA/NSA/Sub6 - SM-G998B
Launch
Announced2021, August 112021, January 14
StatusAvailable. Released 2021, August 27Available. Released 2021, January 29
Body
BuildGlass front (Gorilla Glass Victus) (folded), plastic front (unfolded), glass back (Gorilla Glass Victus), aluminum frameGlass front (Gorilla Glass Victus), glass back (Gorilla Glass Victus), aluminum frame
DimensionsUnfolded: 158.2 x 128.1 x 6.4 mmFolded: 158.2 x 67.1 x 14.4-16 mm165.1 x 75.6 x 8.9 mm (6.5 x 2.98 x 0.35 in)
SIMNano-SIM + eSIM· Nano-SIM + eSIM· Nano-SIM + Nano-SIM + eSIM (max 2 at a time)
Weight271 g (9.56 oz)227 g (Sub6), 229 g (mmWave) (8.01 oz)
 IPX8 water resistant (up to 1.5m for 30 min) Armor aluminum frame with tougher drop and scratch resistance (advertised) Stylus supportIP68 dust/water resistant (up to 1.5m for 30 min) Stylus support
Display
Protection-Corning Gorilla Glass Victus
Resolution1768 x 2208 pixels (~374 ppi density)1440 x 3200 pixels, 20:9 ratio (~515 ppi density)
Size7.6 inches, 179.9 cm2 (~88.8% screen-to-body ratio)6.8 inches, 112.1 cm2 (~89.8% screen-to-body ratio)
TypeFoldable Dynamic AMOLED 2X, 120Hz, HDR10+, 1200 nits (peak)Dynamic AMOLED 2X, 120Hz, HDR10+, 1500 nits (peak)
 Cover display: Dynamic AMOLED 2X, 120Hz, Corning Gorilla Glass Victus 6.2 inches, 832 x 2268 pixels, 25:9 ratioAlways-on display
Platform
CPUOcta-core (1x2.84 GHz Cortex-X1 & 3x2.42 GHz Cortex-A78 & 4x1.80 GHz Cortex-A55)Octa-core (1x2.9 GHz Cortex-X1 & 3x2.80 GHz Cortex-A78 & 4x2.2 GHz Cortex-A55) - InternationalOcta-core (1x2.84 GHz Cortex-X1 & 3x2.42 GHz Cortex-A78 & 4x1.80 GHz Cortex-A55) - USA/China
ChipsetQualcomm SM8350 Snapdragon 888 5G (5 nm)Exynos 2100 (5 nm) - InternationalQualcomm SM8350 Snapdragon 888 5G (5 nm) - USA/China
GPUAdreno 660Mali-G78 MP14 - InternationalAdreno 660 - USA/China
OSAndroid 11, up to 4 major Android upgrades, One UI 6.1Android 11, up to 4 major Android upgrades, One UI 6.1
Memory
Card slotNoNo
Internal256GB 12GB RAM, 512GB 12GB RAM128GB 8GB RAM, 128GB 12GB RAM, 256GB 12GB RAM, 256GB 16GB RAM, 512GB 12GB RAM, 512GB 16GB RAM
 UFS 3.1UFS 3.1
Main Camera
FeaturesLED flash, HDR, panoramaLaser AF, LED flash, auto-HDR, panorama
Quad-108 MP, f/1.8, 24mm (wide), 1/1.33", 0.8µm, PDAF, OIS 10 MP, f/2.4, 72mm (telephoto), 1/3.24", 1.22µm, dual pixel PDAF, OIS, 3x optical zoom 10 MP, f/4.9, 240mm (periscope telephoto), 1/3.24", 1.22µm, dual pixel PDAF, OIS, 10x optical zoom 12 MP, f/2.2, 13mm (ultrawide), 1/2.55", 1.4µm, dual pixel PDAF, Super Steady video
Triple12 MP, f/1.8, 26mm (wide), 1/1.76", 1.8µm, dual pixel PDAF, OIS 12 MP, f/2.4, 52mm (telephoto), 1/3.6", 1.0µm, PDAF, OIS, 2x optical zoom 12 MP, f/2.2, 123˚, 12mm (ultrawide), 1.12µm-
Video4K@60fps, 1080p@60/240fps (gyro-EIS), HDR10+8K@24fps, 4K@30/60fps, 1080p@30/60/120/240fps, HDR10+, stereo sound rec., gyro-EIS
Selfie camera
FeaturesHDRHDR
Single4 MP, f/1.8, 2.0µm, under display Cover camera: 10 MP, f/2.2, 26mm (wide), 1/3", 1.22µm40 MP, f/2.2, 26mm (wide), 1/2.8", 0.7µm, PDAF
Video4K@30fps, 1080p@30fps, gyro-EIS4K@30/60fps, 1080p@30fps
Sound
3.5mm jack NoNo
35mm jackNoNo
Loudspeaker Yes, with stereo speakersYes, with stereo speakers
 32-bit/384kHz audio Tuned by AKG32-bit/384kHz audio Tuned by AKG
Comms
Bluetooth5.2, A2DP, LE, aptX HD5.2, A2DP, LE
NFCYesYes
PositioningGPS, GLONASS, GALILEO, BDSGPS, GLONASS, BDS, GALILEO
RadioNoFM radio (Snapdragon model only; market/operator dependent)
USBUSB Type-C 3.2USB Type-C 3.2, OTG
WLANWi-Fi 802.11 a/b/g/n/ac/6e, dual-band, Wi-Fi DirectWi-Fi 802.11 a/b/g/n/ac/6e, dual-band, Wi-Fi Direct
Features
SensorsFingerprint (side-mounted), accelerometer, gyro, proximity, compass, barometerFingerprint (under display, ultrasonic), accelerometer, gyro, proximity, compass, barometer
 Bixby natural language commands and dictation Samsung DeX (desktop experience support) Samsung Pay (Visa, MasterCard certified) Ultra Wideband (UWB) supportSamsung DeX, Samsung Wireless DeX (desktop experience support) Bixby natural language commands and dictation Samsung Pay (Visa, MasterCard certified) Ultra Wideband (UWB) support
Battery
Charging25W wired 11W wireless 4.5W reverse wireless25W wired, PD3.0 15W wireless (Qi) 4.5W reverse wireless
TypeLi-Po 4400 mAhLi-Ion 5000 mAh
Misc
ColorsPhantom Black, Phantom Silver, Phantom Green, Thom Browne Edition, Wooyoungmi EditionPhantom Black, Phantom Silver, Phantom Titanium, Phantom Navy, Phantom Brown, Navy
ModelsSM-F926B, SM-F926B/DS, SM-F926U, SM-F926U1, SM-F926W, SM-F9260, SM-F926NSM-G998B, SM-G998B/DS, SM-G998U, SM-G998U1, SM-G998W, SM-G998N, SM-G9980
Price€ 453.57 / $ 367.74 / £ 449.99$ 240.01 / C$ 353.20 / £ 202.99 / € 264.99
SAR0.73 W/kg (head)     1.22 W/kg (body)0.77 W/kg (head)     1.02 W/kg (body)
SAR EU1.04 W/kg (head)     1.44 W/kg (body)0.71 W/kg (head)     1.58 W/kg (body)
Pricing
128GB 12GB RAM-$ 384.99
256GB 12GB RAM-$ 998.00
512GB 12GB RAM-$ 1,179.99
RENEWED-$ 459.00
Tests
Battery life Endurance rating 75h Endurance rating 114h
Camera Photo / Video Photo / Video
Display- Contrast ratio: Infinite (nominal)
Loudspeaker -25.6 LUFS (Very good) -25.5 LUFS (Very good)
Performance AnTuTu: 635918 (v8), 752218 (v9) GeekBench: 12719 (v4.4), 3239 (v5.1) GFXBench: 38fps (ES 3.1 onscreen) AnTuTu: 657150 (v8) GeekBench: 3518 (v5.1) GFXBench: 33fps (ES 3.1 onscreen)

Samsung Galaxy Z Fold3 5G

  • Innovative foldable design for enhanced multitasking
  • Large, immersive inner display
  • S Pen support (sold separately)
  • Unique form factor and premium feel

  • Significantly shorter battery life
  • Crease visible on the inner display
  • Lower durability compared to traditional smartphones
  • Higher price point

Samsung Galaxy S21 Ultra 5G

  • Exceptional battery life (114h endurance)
  • Brighter and more color-accurate display
  • Versatile camera system with superior zoom capabilities
  • More durable and robust design

  • Conventional smartphone design
  • No foldable display
  • Larger and heavier than some competitors
  • S Pen support not integrated

Display Comparison

The Z Fold3 boasts a foldable Dynamic AMOLED 2X display, while the S21 Ultra features a 6.8-inch Dynamic AMOLED 2X display. The S21 Ultra achieves a measured peak brightness of 1023 nits, surpassing the Z Fold3’s 922 nits, resulting in better outdoor visibility. While both utilize AMOLED technology, the Z Fold3’s foldable nature introduces a crease, a trade-off for its larger screen real estate. The S21 Ultra’s ‘Infinite’ contrast ratio, typical of AMOLED panels, delivers deep blacks and vibrant colors. The Z Fold3’s inner display, while innovative, is more susceptible to damage and lacks the same level of scratch resistance as the S21 Ultra’s Gorilla Glass Victus.

Camera Comparison

Both devices offer versatile camera systems, but the S21 Ultra excels in zoom capabilities. While both feature photo and video recording, the S21 Ultra’s superior sensor size and optical image stabilization (OIS) provide better low-light performance and sharper images. The Z Fold3’s under-display camera on the inner screen is a novel feature, but image quality is noticeably inferior to the S21 Ultra’s front-facing camera. The S21 Ultra’s 108MP main sensor captures more detail than the Z Fold3’s, and its 10x optical zoom lens offers significantly greater reach. The 2MP macro cameras on both devices are largely superfluous and offer limited practical benefit.

Performance

Both phones utilize the Qualcomm Snapdragon 888 5G chipset (in USA/China variants), but the S21 Ultra’s international variant features the Exynos 2100. The S21 Ultra’s Exynos 2100 variant has a slightly higher peak CPU clock speed (2.9 GHz vs 2.84 GHz) compared to the Z Fold3’s Snapdragon 888, though real-world performance differences are minimal. Both devices feature 12GB of RAM, ensuring smooth multitasking. However, the Z Fold3’s larger surface area and more complex cooling system may lead to slightly better sustained performance under heavy load, mitigating potential thermal throttling. The S21 Ultra’s optimized software and more efficient display contribute to better overall power efficiency.

Battery Life

The S21 Ultra’s 114-hour endurance rating significantly outperforms the Z Fold3’s 75-hour rating. This difference is primarily due to the S21 Ultra’s larger battery capacity and more efficient display. Both devices support 25W wired charging, 15W/11W wireless charging, and 4.5W reverse wireless charging. However, the S21 Ultra’s superior battery life means users will rely on charging less frequently. The Z Fold3’s foldable design necessitates a dual-battery configuration, which may contribute to its lower endurance.

Buying Guide

Buy the Samsung Galaxy Z Fold3 5G if you demand ultimate multitasking capabilities, a large, immersive display for media consumption and productivity, and are willing to accept compromises in battery life and durability for a cutting-edge foldable experience. Buy the Samsung Galaxy S21 Ultra 5G if you prioritize camera versatility, all-day battery life, a brighter and more color-accurate display, and a more conventional, durable smartphone design.

Frequently Asked Questions

❓ Does the Exynos 2100 chip in the international S21 Ultra overheat during prolonged gaming sessions?
While the Exynos 2100 historically faced thermal concerns, Samsung implemented optimizations in the S21 Ultra. Benchmarks and user reports indicate that thermal throttling is manageable, though the Snapdragon 888 variant generally exhibits slightly better sustained performance. The S21 Ultra’s larger chassis and improved cooling system help mitigate heat buildup.
❓ Is the 2MP macro camera on either device worth using for detailed close-up shots?
The 2MP macro cameras on both the Z Fold3 and S21 Ultra are largely underwhelming. Their low resolution and lack of optical image stabilization result in soft, noisy images. While they can capture close-up shots, the quality is significantly inferior to using the main camera in Pro mode with digital zoom.
❓ Can the Galaxy Z Fold3 handle demanding games like PUBG at 90fps?
The Z Fold3 can run PUBG at 90fps, but maintaining a stable framerate depends on the graphics settings and the intensity of the gameplay. The Snapdragon 888 is capable, but the foldable design's thermal management may lead to some frame drops during extended sessions. Lowering graphics settings is recommended for a smoother experience.
❓ How does the Z Fold3's under-display camera affect the overall viewing experience?
The under-display camera on the Z Fold3 is visible under certain lighting conditions, appearing as a slight distortion in the display. While Samsung has made improvements to minimize its visibility, it's still noticeable and can be distracting for some users. Image quality from this camera is also significantly lower than the front-facing camera.