Galaxy S21 Ultra 5G vs Galaxy Z Fold3 5G
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Galaxy S21 Ultra 5G
Starting at
£268.86£1,316.00 new
Galaxy Z Fold3 5G
Starting at
£341.28What's the difference between the Galaxy S21 Ultra 5G and Galaxy Z Fold3 5G?
Galaxy S21 Ultra 5G vs Z Fold3 5G comes down to the chipset, battery and screen size. Refurbished, the Galaxy S21 Ultra 5G starts at £268.86, £72.42 less than the Galaxy Z Fold3 5G.
Refurbished from
Chipset
Battery
Screen size
Screen type
Software updates
- Chipset: Exynos 2100 (5 nm), Qualcomm SM8350 Snapdragon 888 5G (5 nm) on the Galaxy S21 Ultra 5G, Qualcomm SM8350 Snapdragon 888 5G (5 nm) on the Galaxy Z Fold3 5G.
- The Galaxy S21 Ultra 5G has a bigger battery: 5000 mAh vs 4400 mAh.
- The Galaxy Z Fold3 5G has a bigger screen: 7.6 inch vs 6.8 inch.
Galaxy S21 Ultra 5G vs Galaxy Z Fold3 5G specs
The Galaxy S21 Ultra 5G and Galaxy Z Fold3 5G both launched in 2021 and offer powerful performance and high-end features, but they suit different users. The S21 Ultra 5G has a larger battery capacity and a traditional phone design with a 6.8 inch Dynamic AMOLED 2X screen, making it a strong choice for those who want long-lasting use in a classic format. The Z Fold3 5G features a foldable 7.6 inch screen, ideal for users who prioritise a larger display for multitasking and media viewing. Both devices share 5G connectivity and 12 GB RAM, but storage options vary slightly. The S21 Ultra 5G comes with a wider range of storage capacities, while the Z Fold3 5G offers a unique foldable screen experience at a slightly heavier weight. Your choice depends on whether you prefer a traditional phone or a foldable device with an expansive screen.
Galaxy S21 Ultra 5G vs Galaxy Z Fold3 5G price
Colour
- BlackStarting at £268.86
- Dark BlueStarting at £268.86
- SilverStarting at £268.86
- BrownStarting at £268.86
- Dark greyStarting at £268.86
- BlackSold out
- GreenSold out
- SilverSold out
Storage
- 256GBSold out
- 512GBSold out
Galaxy S21 Ultra 5G vs Galaxy Z Fold3 5G battery life and software updates
Durability covers battery size and operating system, both important for daily reliability. These two phones have different battery capacities and software details.
Battery Capacity
The Galaxy S21 Ultra 5G has a 5000 mAh battery, which suits users who prioritise longer use between charges. The Galaxy Z Fold3 5G comes with a 4400 mAh battery, which is slightly smaller but still substantial for daily tasks. If you need maximum battery life for all-day use, the S21 Ultra 5G may serve you better.
Operating System
Both deliver a familiar Android experience, but the Z Fold3 5G specifies the OS version, which may matter if you track software updates closely.
Battery
Foldable
Ip rating
OS at launch
Software updates
Wireless charging
Year of release
Galaxy S21 Ultra 5G vs Galaxy Z Fold3 5G performance
Performance depends on chipset, RAM, and storage options. Both phones offer strong specifications suited to demanding apps and multitasking.
Chipsets
The Galaxy S21 Ultra 5G offers two chipset options: Exynos 2100 (5 nm) and Qualcomm SM8350 Snapdragon 888 5G (5 nm). The Galaxy Z Fold3 5G uses the Qualcomm SM8350 Snapdragon 888 5G (5 nm). Both chipsets provide high performance for gaming, multitasking, and productivity, but the S21 Ultra 5G gives you a choice depending on the version you get.
RAM and Storage
Both phones come with 12 GB of RAM, suitable for handling multiple apps and demanding tasks simultaneously. The Galaxy S21 Ultra 5G offers three storage options: 128GB, 256GB, and 512GB. The Galaxy Z Fold3 5G is available with 256GB or 512GB storage. If you want a lower storage capacity, the S21 Ultra 5G provides an option not found in the Z Fold3 5G.
Chipset
RAM
Galaxy S21 Ultra 5G vs Galaxy Z Fold3 5G screen
Screen quality and size affect how you interact with your device daily. Both phones offer high refresh rates and advanced AMOLED technology, but the Z Fold3 5G has a notably larger foldable display.
Screen Size and Resolution
The Galaxy S21 Ultra 5G has a 6.8 inch screen with a resolution of 1440 x 3200 pixels, ideal if you prefer a large but traditional phone screen. The Galaxy Z Fold3 5G features a foldable 7.6 inch screen with a resolution of 1768 x 2208 pixels, providing more room for multitasking or media consumption when unfolded.
Screen Technology and Refresh Rate
Both phones use Dynamic AMOLED 2X technology and support a 120 Hz refresh rate. The Z Fold3 5G uses a foldable version of this screen type, which adds flexibility in how you use the device. Both screens offer smooth visuals and vibrant colours suitable for gaming, video playback, and everyday use.
Refresh rate
Resolution
Screen size
Screen type
Galaxy S21 Ultra 5G vs Galaxy Z Fold3 5G camera
Camera type
Front camera
Main camera
Galaxy S21 Ultra 5G vs Galaxy Z Fold3 5G size and design
This section covers connectivity, network compatibility, physical size, and card slots, which affect how you use the device day to day.
Network and SIM Options
Both the Galaxy S21 Ultra 5G and Galaxy Z Fold3 5G are unlocked 5G phones, supporting physical SIM and eSIM. This means you can choose your carrier freely and use dual SIM setups for personal and work numbers. Both use USB-C connectors for charging and data.
Weight
The Galaxy S21 Ultra 5G weighs 227 g, which suits users seeking a lighter phone for day-long carrying. The Galaxy Z Fold3 5G weighs 271 g, reflecting its larger foldable screen and different design. If you prefer a more substantial feel and a bigger screen, the Z Fold3 5G fits that preference.
Storage Card Slots
Neither device includes an SD card slot, so storage capacity depends on the internal options you choose at purchase.
Carrier compatibility
Connector
Depth
Height
Mobile network
Release date
SD card slot
SIM card
Weight
Width
Galaxy S21 Ultra 5G or Galaxy Z Fold3 5G: which should you buy?
Buy the Galaxy S21 Ultra 5G if
- you want to spend less: it starts at £268.86, £72.42 less than the Galaxy Z Fold3 5G
- you want a bigger battery (5000 mAh vs 4400 mAh)
- you want a lighter build (227 g vs 271 g)
Buy the Galaxy Z Fold3 5G if
- you want a bigger screen (7.6 inch vs 6.8 inch)
What our customers say
Customers who bought the Galaxy S21 Ultra 5G often praise its condition, with many saying it looks almost new even in good condition options. Several mention the phone works like new, is fast and reliable, and comes with plenty of storage variety. Some users highlight the phone's battery life and screen quality positively, while a few report issues with battery performance or device condition. Overall, buyers appreciate the performance and classic design of the S21 Ultra 5G for everyday use and value it as a sustainable choice.
For the Galaxy Z Fold3 5G, customers highlight the device's good condition and ease of use. Many say the phone looks like new and they enjoy the larger foldable screen for multitasking and media. Users describe it as a good quality phone with solid performance, though some note the battery does not last as long as previous devices they had. The Z Fold3 5G appeals to those who want a larger, versatile screen and are comfortable with a slightly heavier device.
Both phones satisfy buyers who want premium features in different forms. The Galaxy S21 Ultra 5G suits those who prefer a traditional large smartphone with a strong battery, while the Galaxy Z Fold3 5G fits users interested in a foldable design and expanded screen space.
Galaxy S21 Ultra 5G vs Galaxy Z Fold3 5G FAQs
Galaxy S21 Ultra 5G vs Z Fold3 5G comes down to the chipset, battery and screen size. Chipset: Exynos 2100 (5 nm), Qualcomm SM8350 Snapdragon 888 5G (5 nm) on the Galaxy S21 Ultra 5G, Qualcomm SM8350 Snapdragon 888 5G (5 nm) on the Galaxy Z Fold3 5G. The Galaxy S21 Ultra 5G has a bigger battery: 5000 mAh vs 4400 mAh.
The Galaxy S21 Ultra 5G is cheaper refurbished, from £268.86 compared with £341.28 for the Galaxy Z Fold3 5G.
The Galaxy S21 Ultra 5G has a bigger battery: 5000 mAh vs 4400 mAh.
Updates for the Galaxy S21 Ultra 5G ended in Feb 2026. Updates for the Galaxy Z Fold3 5G ended in Sep 2026.
Refurbished, the Galaxy S21 Ultra 5G comes in 128GB, 256GB and 512GB, and the Galaxy Z Fold3 5G in 256GB and 512GB.
