Galaxy S21 Ultra 5G vs Galaxy Z Flip4
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Galaxy S21 Ultra 5G
Starting at
£268.86£1,316.00 new
Galaxy Z Flip4
Starting at
£230.00What's the difference between the Galaxy S21 Ultra 5G and Galaxy Z Flip4?
Galaxy S21 Ultra 5G vs Z Flip4 comes down to the chipset, RAM and battery. Refurbished, the Galaxy Z Flip4 starts at £230, £38.86 less than the Galaxy S21 Ultra 5G. The Galaxy Z Flip4 is the newer model, released in 2022.
Refurbished from
Chipset
RAM
Battery
Screen size
Main camera
- Chipset: Exynos 2100 (5 nm), Qualcomm SM8350 Snapdragon 888 5G (5 nm) on the Galaxy S21 Ultra 5G, Qualcomm SM8475 Snapdragon 8+ Gen 1 (4 nm) on the Galaxy Z Flip4.
- The Galaxy S21 Ultra 5G has more RAM: 12 GB vs 8 GB.
- The Galaxy S21 Ultra 5G has a bigger battery: 5000 mAh vs 3700 mAh.
Galaxy S21 Ultra 5G vs Galaxy Z Flip4 specs
The Galaxy S21 Ultra 5G and Galaxy Z Flip4 differ mainly in design, performance, and camera capabilities, making each suited to different needs. The S21 Ultra 5G offers a larger 6.8 inch high-resolution screen and a very high megapixel count for both front and main cameras, ideal for users who prioritise screen detail and photography. It has a larger 5000 mAh battery and more RAM for handling demanding apps. The Z Flip4 features a unique foldable design that is slimmer and lighter, with a slightly smaller 6.7 inch screen and a simpler camera setup. It uses a newer Snapdragon 8+ Gen 1 chipset and comes with Android 12. Choose the S21 Ultra 5G for power and display size, or the Z Flip4 for portability and a modern foldable style.
Galaxy S21 Ultra 5G vs Galaxy Z Flip4 price
Colour
- BlackStarting at £268.86
- Dark BlueStarting at £268.86
- SilverStarting at £268.86
- BrownStarting at £268.86
- Dark greyStarting at £268.86
- BlueSold out
- GreySold out
- RedSold out
- Dark purpleSold out
- Rose GoldSold out
- YellowSold out
- GreenSold out
- WhiteSold out
Storage
- 128GBSold out
- 256GBSold out
- 512GBSold out
Galaxy S21 Ultra 5G vs Galaxy Z Flip4 battery life and software updates
Battery capacity and operating system version influence how long a phone lasts between charges and the software experience. The two phones differ in these key durability features.
Battery Capacity
The Galaxy S21 Ultra 5G has a 5000 mAh battery, which suits people who need longer use between charges, such as heavy users or those often away from power sources. The Galaxy Z Flip4 has a 3700 mAh battery, which is smaller and may be enough for everyday use or lighter phone activity.
Operating System
This may appeal to those wanting newer system features and interface improvements.
Battery
Foldable
Ip rating
OS at launch
Software updates
Wireless charging
Year of release
Galaxy S21 Ultra 5G vs Galaxy Z Flip4 performance
Processor and memory affect how smoothly a phone runs apps and multitasks. Both phones have strong performance, but with differences in chipset technology and RAM size.
Processor Chipset
The Galaxy Z Flip4 uses the Qualcomm SM8475 Snapdragon 8+ Gen 1 built on a 4 nm process, which is a newer chipset generation. The Galaxy S21 Ultra 5G uses either the Exynos 2100 or Snapdragon 888 5G, both built on a 5 nm process. The chipset in the Z Flip4 may deliver improvements in efficiency and speed for users interested in the latest mobile chip technology.
RAM Capacity
The Galaxy S21 Ultra 5G comes with 12 GB of RAM, making it well suited for users who keep many apps open or use memory-intensive software. The Galaxy Z Flip4 has 8 GB of RAM, which supports everyday apps smoothly and suits users with typical multitasking needs.
Storage Options
Both devices are available in 128GB, 256GB, and 512GB storage options, so buyers can choose based on how much space they need for apps, photos, and files.
Chipset
RAM
Galaxy S21 Ultra 5G vs Galaxy Z Flip4 screen
Screen size, resolution, and refresh rate shape the viewing experience. Both phones use Dynamic AMOLED 2X technology with 120 Hz refresh, but differ in size and resolution.
Screen Size
The Galaxy S21 Ultra 5G has a 6.8 inch screen, offering a bit more room for watching videos, gaming, or browsing. The Galaxy Z Flip4 features a slightly smaller 6.7 inch screen, which still provides a roomy display but in a more compact form.
Screen Resolution
The S21 Ultra 5G has a higher resolution of 1440 x 3200 pixels, delivering sharper detail for high definition content and fine text. The Z Flip4's 1080 x 2640 resolution is still clear and vibrant but suits users who prefer a balance between resolution and battery use.
Refresh Rate
Both phones support a 120 Hz refresh rate, making animations and scrolling smoother. This benefits users who value fluid display performance for gaming or general navigation.
Refresh rate
Resolution
Screen size
Screen type
Galaxy S21 Ultra 5G vs Galaxy Z Flip4 camera
Camera megapixels affect the clarity and detail of photos and selfies. These two Samsung phones have very different camera setups that suit different photography needs.
Front Camera Megapixels
The Galaxy S21 Ultra 5G has a 40 megapixel front camera, ideal for users who want highly detailed selfies or video calls with excellent image quality. The Galaxy Z Flip4 has a 10 megapixel front camera, which supports good everyday selfies and video chats.
Main Camera Megapixels
The S21 Ultra 5G offers a 108 megapixel main camera, which captures very high detail photos and is suited to photography enthusiasts or those who want large prints or cropping flexibility. The Z Flip4's 12 megapixel main camera is simpler and fits users who take typical photos for social media and casual use.
Camera type
Front camera
Main camera
Galaxy S21 Ultra 5G vs Galaxy Z Flip4 size and design
Other features like device size, weight, and connectivity shape how a phone fits your lifestyle and daily use. These differ clearly between the Galaxy S21 Ultra 5G and Galaxy Z Flip4.
Device Dimensions and Weight
The Galaxy Z Flip4 is slimmer at 6.9 mm depth compared to the S21 Ultra 5G's 8.9 mm. It is also lighter at 187 g versus 227 g, making it easier to carry and pocket. The width of the Z Flip4 is narrower at 71.9 mm compared to 75.6 mm for the S21 Ultra 5G, which helps with one-handed use.
Connector Type
The Galaxy S21 Ultra 5G uses a USB-C connector, while the Galaxy Z Flip4 has a USB Type-C 2.0 connector. This may affect compatibility with some accessories or charging speeds depending on your cables.
Carrier and Network
Both phones are unlocked and support 5G networks, so they can work with a wide range of UK carriers and offer fast mobile data where available.
SIM Cards
Each device supports a physical SIM and an eSIM, giving flexibility for using multiple numbers or plans.
Storage Expandability
Neither phone has an SD card slot, so storage expansion relies on the internal options you choose when buying.
Carrier compatibility
Connector
Depth
Height
Mobile network
Release date
SD card slot
SIM card
Weight
Width
Galaxy S21 Ultra 5G or Galaxy Z Flip4: which should you buy?
Buy the Galaxy S21 Ultra 5G if
- you want more RAM (12 GB vs 8 GB)
- you want a bigger battery (5000 mAh vs 3700 mAh)
- you want a higher-resolution main camera (108 megapixels vs 12 megapixels)
Buy the Galaxy Z Flip4 if
- you want to spend less: it starts at £230, £38.86 less than the Galaxy S21 Ultra 5G
- you want longer software support (until Aug 2027 vs ended Feb 2026)
- you want a lighter build (187 g vs 227 g)
What our customers say
Customers of the Galaxy S21 Ultra 5G often note that the phone looks almost new even in good condition and runs fast and reliably. Many praise its large and clear display, strong battery, and the quality of its cameras. Users appreciate its high performance and memory capacity, which keeps apps running smoothly. Some mention minor cosmetic marks but overall find it a great value for a refurbished device. The phone suits buyers who want a powerful, feature-rich smartphone with a roomy screen.
Reviews for the Galaxy Z Flip4 are more mixed. Some customers highlight the sleek foldable design and excellent screen quality, enjoying its lighter weight and compact size. The battery life is adequate for everyday use but can drain faster with heavier tasks. The simpler camera setup fits casual photography needs. Several users encountered issues with screen reliability or battery condition, but others are pleased with the phone's look and performance for typical daily activities. The Z Flip4 suits buyers wanting a modern foldable phone that is easy to carry and offers good basic functionality.
Both phones appeal to different users: the S21 Ultra 5G is aimed at those who prioritise performance, display size, and camera detail, while the Z Flip4 fits well with users valuing portability, a foldable design, and a recent Android version.
Galaxy S21 Ultra 5G vs Galaxy Z Flip4 FAQs
Galaxy S21 Ultra 5G vs Z Flip4 comes down to the chipset, RAM and battery. Chipset: Exynos 2100 (5 nm), Qualcomm SM8350 Snapdragon 888 5G (5 nm) on the Galaxy S21 Ultra 5G, Qualcomm SM8475 Snapdragon 8+ Gen 1 (4 nm) on the Galaxy Z Flip4. The Galaxy S21 Ultra 5G has more RAM: 12 GB vs 8 GB.
The Galaxy Z Flip4 is cheaper refurbished, from £230 compared with £268.86 for the Galaxy S21 Ultra 5G.
The Galaxy S21 Ultra 5G has a bigger battery: 5000 mAh vs 3700 mAh.
The Galaxy S21 Ultra 5G has a higher-resolution main camera: 108 megapixels vs 12 megapixels.
Updates for the Galaxy S21 Ultra 5G ended in Feb 2026. The Galaxy Z Flip4 gets updates until Aug 2027.
The Galaxy Z Flip4 adds longer software support (until Aug 2027 vs ended Feb 2026) and a lighter build (187 g vs 227 g). Refurbished, it costs £38.86 less (from £230 vs £268.86).
Both come in 128GB, 256GB and 512GB refurbished.
