Galaxy S21 Ultra 5G vs Galaxy Z Fold4
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Galaxy S21 Ultra 5G
Starting at
£268.86£1,316.00 new
Galaxy Z Fold4
Starting at
£419.00What's the difference between the Galaxy S21 Ultra 5G and Galaxy Z Fold4?
Galaxy S21 Ultra 5G vs Z Fold4 comes down to the chipset, battery and screen size. Refurbished, the Galaxy S21 Ultra 5G starts at £268.86, £150.14 less than the Galaxy Z Fold4. The Galaxy Z Fold4 is the newer model, released in 2022.
Refurbished from
Chipset
Battery
Screen size
Screen type
Main camera
- Chipset: Exynos 2100 (5 nm), Qualcomm SM8350 Snapdragon 888 5G (5 nm) on the Galaxy S21 Ultra 5G, Snapdragon 8+ Gen 1 SM8475 (4 nm) on the Galaxy Z Fold4.
- The Galaxy S21 Ultra 5G has a bigger battery: 5000 mAh vs 4400 mAh.
- The Galaxy Z Fold4 has a bigger screen: 7.6 inch vs 6.8 inch.
Galaxy S21 Ultra 5G vs Galaxy Z Fold4 specs
The Galaxy S21 Ultra 5G and Galaxy Z Fold4 both run Android and support 5G, but they cater to different needs. The Galaxy S21 Ultra 5G offers a larger battery and a high-resolution main camera, making it suitable if you prioritise battery life and detailed photography. The Galaxy Z Fold4 features a foldable, much larger screen that is ideal for multitasking and media viewing, plus a newer chipset and options up to 1TB of storage. It also supports dual physical SIM cards if you need that flexibility. The choice depends on whether you want a traditional large smartphone with strong battery and camera performance or a foldable device with more screen space and advanced processing power.
Galaxy S21 Ultra 5G vs Galaxy Z Fold4 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
- Dark redSold out
- BeigeSold out
- GreySold out
- GraySold out
Storage
- 256GBSold out
- 512GBSold out
- 1TBSold out
Galaxy S21 Ultra 5G vs Galaxy Z Fold4 battery life and software updates
Durability covers battery capacity, software updates, and physical design features like foldability. These affect how long you can use each device and how comfortable they are to carry and use daily.
Battery Capacity
The Galaxy S21 Ultra 5G has a 5000 mAh battery, which suits users who need longer battery life for all-day use. The Galaxy Z Fold4 has a 4400 mAh battery, which still supports typical daily use but may require more frequent charging if you use its large foldable screen extensively.
Foldable Design
The Galaxy Z Fold4 has a foldable screen design that lets you switch between a compact phone and a larger tablet-like display. This suits those who value flexibility in screen size and multitasking. The Galaxy S21 Ultra 5G is not foldable and keeps a traditional smartphone form.
Battery
Fast charging
Foldable
Ip rating
Software updates
Wireless charging
Year of release
Galaxy S21 Ultra 5G vs Galaxy Z Fold4 performance
Performance impacts how smoothly the phone runs apps and handles multitasking. The chipset and RAM are key factors here.
Chipset Modernity
The Galaxy Z Fold4 runs on the Snapdragon 8+ Gen 1 chipset built on a 4 nm process, offering efficient and powerful performance for demanding tasks. The Galaxy S21 Ultra 5G uses the Exynos 2100 or Snapdragon 888 chipset on a 5 nm process, which also delivers strong performance but on a slightly older generation chipset.
RAM and Storage Options
Both phones come with 12 GB of RAM, allowing smooth multitasking and app performance. Storage options differ: the Galaxy S21 Ultra 5G offers 128GB, 256GB, or 512GB, while the Galaxy Z Fold4 starts at 256GB and goes up to 1TB. If you need more storage for files or apps, the Z Fold4 provides higher capacity choices.
Chipset
RAM
Galaxy S21 Ultra 5G vs Galaxy Z Fold4 screen
Screen quality affects how you view content and interact with your phone. Size, resolution, refresh rate, and screen type all play a role.
Screen Size and Resolution
The Galaxy Z Fold4 has a larger 7.6-inch foldable screen with a resolution of 1812 x 2176, offering a more spacious display for video, reading, or multitasking. The Galaxy S21 Ultra 5G has a 6.8-inch screen with a resolution of 1440 x 3200, which is taller and sharper for detailed visuals in a conventional smartphone size.
Screen Type and Refresh Rate
Both phones feature Dynamic AMOLED 2X screens with a 120 Hz refresh rate, providing vibrant colours and smooth motion. The Z Fold4's screen is foldable, giving extra versatility in how you use the display.
Refresh rate
Resolution
Screen size
Screen type
Galaxy S21 Ultra 5G vs Galaxy Z Fold4 camera
Camera quality and front camera specs influence photo and video experiences, as well as video calls.
Main Camera Detail
The Galaxy S21 Ultra 5G has a 108-megapixel main camera, suited for capturing highly detailed photos. The Galaxy Z Fold4 has a 50-megapixel main camera, which still offers strong image quality but with fewer megapixels.
Front Camera Resolution
The Galaxy S21 Ultra 5G's front camera has 40 megapixels, supporting detailed selfies and video calls. The Galaxy Z Fold4 has a 4-megapixel front camera, which may be sufficient for casual video calls but with less resolution for detailed self-portraits.
Camera type
Front camera
Main camera
Galaxy S21 Ultra 5G vs Galaxy Z Fold4 size and design
Additional features include physical size, SIM options, and weight, which affect portability and network flexibility.
Physical Dimensions and Weight
The Galaxy S21 Ultra 5G measures 165.1 mm tall, 75.6 mm wide, and 8.9 mm deep, weighing 227 g. The Galaxy Z Fold4 is shorter and thinner at 155.1 mm tall and 6.3 mm deep but much wider when unfolded at 130.1 mm and heavier at 263 g. The Z Fold4 suits those who want a larger screen and don't mind extra weight and width when unfolded. The S21 Ultra 5G fits more easily in a pocket.
SIM Card Options
The Galaxy Z Fold4 supports dual physical SIM cards plus eSIM, ideal if you want to use two different phone numbers or networks simultaneously. The Galaxy S21 Ultra 5G supports one physical SIM and eSIM.
Connector Type
Both devices use USB-C connectors, compatible with common charging and data cables.
Carrier Compatibility and Network
Both phones are unlocked and support 5G networks, giving you flexibility in choosing your mobile provider and fast network speeds.
Carrier compatibility
Connector
Depth
Height
Mobile network
Release date
SD card slot
SIM card
Weight
Width
Galaxy S21 Ultra 5G or Galaxy Z Fold4: which should you buy?
Buy the Galaxy S21 Ultra 5G if
- you want to spend less: it starts at £268.86, £150.14 less than the Galaxy Z Fold4
- you want a bigger battery (5000 mAh vs 4400 mAh)
- you want a higher-resolution main camera (108 megapixels vs 50 megapixels)
Buy the Galaxy Z Fold4 if
- you want a bigger screen (7.6 inch vs 6.8 inch)
- you want longer software support (until Aug 2027 vs ended Feb 2026)
What our customers say
Customers who bought the Galaxy S21 Ultra 5G often praise its condition, with many saying the phone looks almost new or brand new even in good or fair condition. They highlight the phone's speed and reliability, with positive comments on its performance and battery life. Some note the phone works well for their needs and appreciate the device as a sustainable choice compared to buying new.
Buyers of the Galaxy Z Fold4 comment on its excellent shape and performance, with many saying it looks like new or very close to new. The foldable screen is generally well received despite some minor marks or a visible crease. Users mention good battery life and fast performance, describing the phone as their fastest device yet. The size and unique features attract users who want something special.
Both devices suit different users well: the S21 Ultra 5G appeals to those wanting a traditional large smartphone with strong cameras and battery, while the Z Fold4 is aimed at users who want a foldable screen, higher storage options, and dual SIM flexibility.
Galaxy S21 Ultra 5G vs Galaxy Z Fold4 FAQs
Galaxy S21 Ultra 5G vs Z Fold4 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, Snapdragon 8+ Gen 1 SM8475 (4 nm) on the Galaxy Z Fold4. 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 £419 for the Galaxy Z Fold4.
The Galaxy S21 Ultra 5G has a bigger battery: 5000 mAh vs 4400 mAh.
The Galaxy S21 Ultra 5G has a higher-resolution main camera: 108 megapixels vs 50 megapixels.
Updates for the Galaxy S21 Ultra 5G ended in Feb 2026. The Galaxy Z Fold4 gets updates until Aug 2027.
The Galaxy Z Fold4 adds a bigger screen (7.6 inch vs 6.8 inch) and longer software support (until Aug 2027 vs ended Feb 2026). Refurbished, it costs £150.14 more (from £419 vs £268.86).
Refurbished, the Galaxy S21 Ultra 5G comes in 128GB, 256GB and 512GB, and the Galaxy Z Fold4 in 256GB, 512GB and 1TB.
