Realme C21 Specifications, Tests and Review

The Realme C21 has a height of 165.2 mm, a width of 76.4 mm and a thickness of 8.9 mm. The weight of the phone is 190 g.

The screen size reaches 6.5" inches. With a large display, phone offers a great experience for watching videos, playing games and reading. The best phones today are 6.5'' or more. They have the advantage of a large display area that allows you to see more content than with conventional display sizes. LCD displays are currently taking a back seat. This is mainly due to higher power consumption. In addition, they have the disadvantage of lower colour contrast, which can be reflected e.g. in the resulting photos. On the other hand, phones with LCD displays are in general cheaper than those with OLED technology.

Display Resolution of Realme C21 is 1600 x 720 pixels. A higher display resolution is a prerequisite for a sharper image. The standard for mid-range phones today is a Full HD resolution of 1920 × 1080 px. Cheaper phones, which usually have a smaller diagonal, have an HD resolution of 1280 × 720 px. Smaller resolutions can only be found in older models. Best phones, on the other hand, have a 4K resolution of 3840 x 2160 px.

Realme C21 is equipped with MediaTek Helio G35. The number of processor cores is 8. It is a number of cores that plays an important role in evaluating the performance of phone as it is responsible for computing operations. Smartphones already commonly have a core count of around 4 to 8. Multi-core processors can perform better and reduce the processing time of a request to a minimum, which is reflected in the responsiveness of the phone, e.g. in the speed of opening applications. The processor frequency indicates how many instructions phone can process in 1 second. The higher the frequency, the better the performance. Standard processor frequency range today is between 1.8 GHz and 2.8 GHz. Realme C21 reaches the frequency of 2.3 GHz.

The processor also includes the graphics accelerator PowerVR GE8320.

The phone´s internal memory capacity is 32 GB. The size of the internal storage determines e.g., how many photos, songs, movies, or applications you can store on your phone. This memory capacity is ideal for those who have a few basic apps and a few dozen photos on their phone. If you don't expect to use your phone to play games or need to store high-resolution photos, this size should be sufficient. There is almost no probability you're likely to see this low capacity on new smartphones. The standard memory today is around 64 and 128 GB. The best phones have internal memory of 256 GB or more. Luckily, most smartphone manufacturers nowadays offer models with different memory sizes to suit every user.

An additional option to increase the storage capacity of this model is to insert a memory card.

RAM memory of the Realme C21 is LPDDR4X SDRAM - 3 GB. Most powerful phones currently have an operating memory of 12 GB or more, which is especially useful for demanding users such as gaming enthusiasts. Normally, phones nowadays have 6 to 8 GB of RAM, which means that the phone can easily handle normal operation and more demanding applications. Operating memory of less than 4 GB is found in lower-end phones or older models, and they are suitable for low-end users who don't use demanding applications and have the phone more for basic use.

The rear camera of the Realme C21 is equipped with 3 lenses, with each lens having a different role in taking pictures. Most common lens you'll see on smartphones is a wide-angle lens, telephoto lens or macro lens. A wide-angle lens is mainly used to capture landscapes and other spatially larger compositions where a wide field of view is needed. A telephoto lens is designed for photographing subjects at a distance and often has an optical zoom. A macro lens is ideal for close-ups and small objects. The resolution of the main lens is 13 Megapixel. Higher resolution does not necessarily mean super high quality photos. Furthermore, it depends on the pixel size but also on other important factors. The aperture of main lens reaches F/2.2 value. The best phones have a lens with an aperture of up to F/1.5, where more light can pass through sensor and photos will be of a high quality even in low light conditions. However, lenses with apertures around F/1.8 to F/2.2 are the most common. The lower the number after the slash, the better the photo quality.

Digital zoom in this case offers zooming up to 4x. Of course, the higher the lens value, the more distant object can be zoomed in. Nonetheless, the disadvantage of digital zoom is that the quality and sharpness of photo deteriorates when using it.

Second camera
The resolution reaches size of 2 Megapixel. Furthermore, the second lens is equipped with aperture of F/2.4.

Third camera
The resolution of third lens is then 2 Megapixel. Last but not least, third lens is equipped with a lens aperture of F/2.4.

Front camera
The front camera of phone Realme C21 has one lens. This number of lenses is standard on most smartphones nowadays. The resolution of front lens reaches 5 Megapixel. Again, it should be noted that resolution is only one of several other significant factors that affect resulting quality of a photo. The main lens is also equipped with aperture of F/2.2.

The facial recognition feature is just a nice cherry on top.

The battery size of Realme C21 is 5000 mAh. Nevertheless, battery capacity is not the only factor that affects the phone's battery life. For example - the size of the display, the performance of the processor, the use of data functions and, of course, the intensity of use of phone in general all have a significant impact on battery life. Standard for most smartphones today is a battery capacity of around 4500 to 5000 mAH. Phones with this battery size usually guarantee a phone life of at least 1 day. Older or cheaper smartphone models can then reach battery capacities typically around 2500 mAH and below. With this capacity, you may find that if you use your phone heavily, you may need to recharge your phone during the day.

Realme C21 supports 4G. 5G connectivity, which is slowly replacing standard 4G connectivity, is still more the preserve of the latest phones. The operating system in this case is Android 10.

Basic connectivity standards also include Bluetooth 5.0, making it easy to communicate wirelessly with other devices such as headphones, tablets, speakers and smartwatches.