Galaxy S21 5G vs Realme C21
Shop Samsung Galaxy
Galaxy S21 5G
Starting at
£171.33£1,290.00 new
Realme C21
Starting at
£198.00What's the difference between the Galaxy S21 5G and Realme C21?
Galaxy S21 5G vs Realme C21 comes down to the chipset, RAM and battery. Refurbished, the Galaxy S21 5G starts at £171.33, £26.67 less than the Realme C21.
Refurbished from
Chipset
RAM
Battery
Screen size
Screen type
- Chipset: Exynos 2100 (5 nm), Qualcomm SM8350 Snapdragon 888 5G (5 nm) on the Galaxy S21 5G, Mediatek MT6765G Helio G35 on the Realme C21.
- The Galaxy S21 5G has more RAM: 8 GB vs 4 GB.
- The Realme C21 has a bigger battery: 5000 mAh vs 4000 mAh.
Galaxy S21 5G vs Realme C21 specs
The Galaxy S21 5G and Realme C21 both launched in 2021 but suit quite different users. The Galaxy S21 5G offers stronger performance with 8 GB RAM and advanced chipsets, making it better for multitasking and demanding apps. It also supports 5G networks and has a sharper, more vibrant Dynamic AMOLED screen ideal for media lovers. The Realme C21 provides a larger 6.5 inch screen and a bigger 5000 mAh battery, suited to those who prioritise longer battery life and a larger display for everyday use. Its microSDXC slot allows flexible storage expansion. The Galaxy S21 5G suits users looking for speed, screen quality and 5G, while the Realme C21 fits those wanting longer battery life and extra storage at a lower price.
Galaxy S21 5G vs Realme C21 price
Colour
Storage
- 64GBSold out
Galaxy S21 5G vs Realme C21 battery life and software updates
Durability covers battery capacity, software updates and operating system. Both phones run Android and were released in 2021. Battery size and update support differ, which affects how long each device can stay powered and current.
Battery Capacity
The Realme C21 has a 5000 mAh battery, which offers longer usage between charges. This suits users who spend extended time away from power sources. The Galaxy S21 5G has a 4000 mAh battery, providing solid all-day use but with less capacity than the Realme C21.
Battery
Foldable
Software updates
Year of release
Galaxy S21 5G vs Realme C21 performance
Performance is defined by the chipset, RAM and storage options. These aspects affect how smoothly apps run and how much data you can store.
Processing Power and RAM
The Galaxy S21 5G offers advanced chipsets with 8 GB of RAM, which keeps everyday apps running smoothly and supports multitasking. The Realme C21 has a Mediatek MT6765G Helio G35 chipset and 4 GB RAM, suited for everyday use.
Storage Options
The Galaxy S21 5G comes in 128GB and 256GB storage options, providing more space for apps, photos and files. The Realme C21 is stocked with 64GB storage, which suits users with lighter storage needs or those who plan to expand storage externally.
Chipset
RAM
Galaxy S21 5G vs Realme C21 screen
Screen quality affects how content appears and how comfortable the display is for viewing. The two phones differ in size, resolution and screen technology.
Screen Size and Resolution
The Realme C21 has a larger 6.5 inch screen, offering more room for watching videos and browsing. It has a 720 x 1600 resolution, good for everyday viewing. The Galaxy S21 5G's 6.2 inch screen is smaller but sharper with a 1080 x 2400 resolution, delivering clearer images and text.
Screen Type
The Galaxy S21 5G features a Dynamic AMOLED 2X screen, which produces vibrant colours and deep contrast. This suits users who value more vivid and immersive visuals. The Realme C21 uses an IPS LCD screen, which provides good colour accuracy and brightness for routine tasks.
Refresh rate
Resolution
Screen size
Screen type
Galaxy S21 5G vs Realme C21 camera
Audiovisual features include front and main cameras. These affect the quality of selfies and photos you capture.
Front Camera
The Galaxy S21 5G has a 10 megapixel front camera, which captures more detail and clarity in selfies and video calls. This suits users who prioritise higher quality front-facing photos.
Main Camera
The Realme C21's main camera has 13 megapixels, which offers a slightly higher resolution for standard photography. This suits users who want clear photos without extra camera features.
Front camera
Main camera
Galaxy S21 5G vs Realme C21 size and design
Other differences include network support, SIM options, physical size and storage expansion. These details affect connectivity, handling and flexibility.
Mobile Network
The Galaxy S21 5G supports 5G networks, enabling faster mobile data speeds where available. This suits users who want improved connectivity and future-proofing. The Realme C21 supports 4G networks.
SIM and Storage Expansion
The Galaxy S21 5G offers dual physical SIM plus eSIM compatibility, giving flexibility in managing multiple lines. The Realme C21 has dual physical SIM slots and a microSDXC card slot, allowing storage to be expanded with a memory card.
Size and Weight
The Galaxy S21 5G measures 151.7 mm in height, 71.2 mm in width and 7.9 mm in depth, weighing 169 g. The Realme C21 is slightly larger and heavier at 16.52 cm height, 7.64 cm width and 0.89 cm depth, weighing 190 g. The Realme C21's size suits users who prefer a larger phone for media, while the Galaxy S21 5G is more compact and lighter.
Carrier compatibility
Connector
Depth
Height
Mobile network
SD card slot
SIM card
Weight
Width
Galaxy S21 5G or Realme C21: which should you buy?
Buy the Galaxy S21 5G if
- you want to spend less: it starts at £171.33, £26.67 less than the Realme C21
- you want more RAM (8 GB vs 4 GB)
- you want an OLED screen
Buy the Realme C21 if
- you want a bigger battery (5000 mAh vs 4000 mAh)
- you want a higher-resolution main camera (13 megapixels vs 12 megapixels)
- you want a memory card slot
Galaxy S21 5G vs Realme C21 FAQs
Galaxy S21 5G vs Realme C21 comes down to the chipset, RAM and battery. Chipset: Exynos 2100 (5 nm), Qualcomm SM8350 Snapdragon 888 5G (5 nm) on the Galaxy S21 5G, Mediatek MT6765G Helio G35 on the Realme C21. The Galaxy S21 5G has more RAM: 8 GB vs 4 GB.
The Galaxy S21 5G is cheaper refurbished, from £171.33 compared with £198 for the Realme C21.
The Realme C21 has a bigger battery: 5000 mAh vs 4000 mAh.
The Realme C21 has a higher-resolution main camera: 13 megapixels vs 12 megapixels.
Updates for the Galaxy S21 5G ended in Feb 2026. We don't have published update dates for the Realme C21.
Refurbished, the Galaxy S21 5G comes in 128GB and 256GB, and the Realme C21 in 64GB.
