OnePlus 9 Pro vs Realme C21
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OnePlus 9 Pro
Starting at
£240.00
Realme C21
Starting at
£198.00What's the difference between the OnePlus 9 Pro and Realme C21?
OnePlus 9 Pro vs Realme C21 comes down to the chipset, RAM and battery. Refurbished, the Realme C21 starts at £198, £42 less than the OnePlus 9 Pro.
Refurbished from
Chipset
RAM
Battery
Screen size
Screen type
- Chipset: Qualcomm SM8350 Snapdragon 888 5G (5 nm) on the OnePlus 9 Pro, Mediatek MT6765G Helio G35 on the Realme C21.
- The OnePlus 9 Pro has more RAM: 8 GB vs 4 GB.
- The Realme C21 has a bigger battery: 5000 mAh vs 4500 mAh.
OnePlus 9 Pro vs Realme C21 specs
The OnePlus 9 Pro and Realme C21 both come from 2021 but serve different needs. The OnePlus 9 Pro suits users who want strong performance, a high-resolution AMOLED screen, and advanced cameras for detailed photos and video calls. It supports 5G and offers more storage options without expandable memory. The Realme C21 fits users looking for longer battery life, a larger capacity battery, and a microSD card slot for extra storage. Its simpler screen and cameras work well for everyday use, and it supports 4G and dual SIMs with physical slots. Both are unlocked and offer solid dual SIM support, making each suitable depending on your priorities in performance, screen quality, and battery endurance.
OnePlus 9 Pro vs Realme C21 price
Colour
- GreenSold out
- SilverSold out
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Storage
- 128GBSold out
- 256GBSold out
- 64GBSold out
OnePlus 9 Pro vs Realme C21 battery life and software updates
Durability here focuses on battery capacity, operating system, and release year. Each device offers features for daily use that suit different priorities in endurance and software.
Battery Capacity
The Realme C21 has a 5000 mAh battery, which is larger than the OnePlus 9 Pro's 4500 mAh. This means the Realme C21 is ideal for users who prioritise longer battery life between charges, especially if you spend extended periods away from power sources. The OnePlus 9 Pro's battery size also supports a full day of use but suits those who balance battery with other advanced features.
Operating System
The OnePlus 9 Pro runs Android 11 and can be upgraded to Android 14 with OxygenOS 14, which is tailored for enhanced user experience and ongoing software updates. The Realme C21 runs Android, offering a straightforward experience suited for everyday tasks. This makes the OnePlus 9 Pro suitable if you want a device with a more recent Android version and a custom operating system experience.
Battery
Foldable
OS at launch
Year of release
OnePlus 9 Pro vs Realme C21 performance
Performance differences come down to chipset, RAM, and storage options. These affect app responsiveness, multitasking, and available space for files and apps.
Processing Power
The OnePlus 9 Pro uses a Qualcomm SM8350 Snapdragon 888 5G chipset built on a 5 nm process, designed for high performance and efficiency. The Realme C21 has a Mediatek MT6765G Helio G35 chipset, suitable for everyday tasks and simpler apps. OnePlus 9 Pro is better for users who run demanding applications or want smoother overall performance.
Memory and Storage
With 8 GB of RAM, the OnePlus 9 Pro keeps more apps open and running smoothly, which benefits multitasking and heavier app use. It is available with 128GB or 256GB of storage, which suits users storing large files or many apps. The Realme C21 offers 4 GB of RAM and 64GB of storage, which works well for everyday use and lighter app needs.
Chipset
RAM
OnePlus 9 Pro vs Realme C21 screen
Screen quality differences affect visual clarity, size, and type of display technology. These impact how you view video, photos, and interact with apps.
Resolution and Display Type
The OnePlus 9 Pro's LTPO Fluid2 AMOLED screen has a resolution of 1440 by 3216 pixels, delivering sharp, vibrant visuals and deep contrast. The Realme C21's IPS LCD screen has a 720 by 1600 pixel resolution, offering a simpler display that works well for basic viewing and daily use. OnePlus 9 Pro suits those who value high definition and rich colours.
Screen Size
The OnePlus 9 Pro features a 6.7 inch screen, providing more room for watching videos, gaming, or multitasking. The Realme C21 has a slightly smaller 6.5 inch screen, which is still comfortable for everyday use and easier to handle with one hand.
Refresh rate
Resolution
Screen size
Screen type
OnePlus 9 Pro vs Realme C21 camera
Audiovisual features focus on camera resolution, which influences photo and video quality for selfies and main images.
Front Camera
The OnePlus 9 Pro has a 16 megapixel front camera, suitable for detailed selfies and clear video calls. The Realme C21's 5 megapixel front camera works well for basic video chats and casual selfies, fitting users who use the front camera less intensively.
Main Camera
With a 48 megapixel main camera, the OnePlus 9 Pro captures more detail and sharper images. The Realme C21's 13 megapixel main camera is designed for everyday photography, producing good quality pictures under typical conditions. OnePlus 9 Pro is better suited for photography enthusiasts or those wanting higher detail.
Front camera
Main camera
OnePlus 9 Pro vs Realme C21 size and design
Miscellaneous features include network support, physical design dimensions, SIM card options, and storage expandability, which affect connectivity and device handling.
Network Compatibility
The OnePlus 9 Pro supports 5G networks, offering faster mobile data where available. The Realme C21 supports 4G, which is widely available and reliable for standard mobile use. Choose based on your network needs and coverage.
SIM and Storage Expansion
Both phones have dual physical SIM slots, allowing use of two SIM cards simultaneously. The Realme C21 includes a microSDXC card slot for expanding storage beyond 64GB, ideal for users who want to add more media or files. The OnePlus 9 Pro does not have an SD card slot, so storage depends on internal capacity.
Size and Weight
The OnePlus 9 Pro measures 163.2 mm tall, 73.6 mm wide, and 8.7 mm deep, weighing 197 g. The Realme C21 is slightly taller at 165.2 mm, wider at 76.4 mm, and a bit deeper at 8.9 mm, weighing 190 g. The Realme C21's slightly larger footprint suits users who prefer a wider grip, while the OnePlus 9 Pro is narrower but a little heavier.
Carrier compatibility
Connector
Depth
Height
Mobile network
SD card slot
SIM card
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Width
OnePlus 9 Pro or Realme C21: which should you buy?
Buy the OnePlus 9 Pro if
- you want more RAM (8 GB vs 4 GB)
- you want an OLED screen
- you want a higher-resolution main camera (48 megapixels vs 13 megapixels)
Buy the Realme C21 if
- you want to spend less: it starts at £198, £42 less than the OnePlus 9 Pro
- you want a bigger battery (5000 mAh vs 4500 mAh)
- you want a lighter build (190 g vs 197 g)
OnePlus 9 Pro vs Realme C21 FAQs
OnePlus 9 Pro vs Realme C21 comes down to the chipset, RAM and battery. Chipset: Qualcomm SM8350 Snapdragon 888 5G (5 nm) on the OnePlus 9 Pro, Mediatek MT6765G Helio G35 on the Realme C21. The OnePlus 9 Pro has more RAM: 8 GB vs 4 GB.
The Realme C21 is cheaper refurbished, from £198 compared with £240 for the OnePlus 9 Pro.
The Realme C21 has a bigger battery: 5000 mAh vs 4500 mAh.
The OnePlus 9 Pro has a higher-resolution main camera: 48 megapixels vs 13 megapixels.
Refurbished, the OnePlus 9 Pro comes in 128GB and 256GB, and the Realme C21 in 64GB.
