realme C21 review: the ultra-low-budget smartphone!


One big plus of the fierce competition in the smartphone market is the range of models available at every price point. It doesn’t matter if your budget is a very modest one. You can still get yourself a smartphone at about 120 USD. We haven’t reviewed such an affordable smartphone for a very long time, but now it is time to take a look at the new realme C21. Read this review and see what 120$ will get you, smartphone-wise:

realme C21: Who is it good for?

This smartphone is a solid choice for:

  • People who want a smartphone at a very low price
  • Users who need a smartphone that can last for two days on a single charge
  • People who want a durable smartphone

Pros and cons

There are many good things about the realme C21:

  • Very low price
  • Solid build quality, certified by TÜV Rheinland
  • Excellent battery life
  • You can use two SIM cards and a microSD simultaneously
  • Fast unlocking (fingerprint sensor and face recognition)

There are downsides to consider as well:

  • The screen’s brightness is underwhelming outdoors
  • It comes with Android 10 instead of Android 11
  • No headset included in the box
  • Dated connectivity options: only Wi-Fi 4, no NFC, no USB-Type C, etc.
Product rating 3/5


It is tough to give a verdict for a smartphone this affordable. At 120$, the manufacturer had to make many compromises to keep some degree of profitability. Therefore, don’t expect any spectacular things from the realme C21. For its meager price, it is a reasonably well-balanced smartphone that shines in the battery and build quality departments. You won’t have to charge it every day, it is competent as long as you don’t run demanding apps and games, and the build quality is certified by TÜV Rheinland for its durability. If your budget is very limited, realme C21 offers a good bang for your buck.

Unboxing the realme C21 smartphone

The realme C21 smartphone comes in a small yellow cardboard box with a minimalistic look. On the top and the sides, you see only the name of the smartphone you just bought. There are some stickers with information about the hardware inside this device, its IMEI number, serial number, and other details on the bottom of the box.

realme c21 comes in a small yellow box

When you open the box, you see another smaller box with a welcome message on it. This smaller box contains two leaflets with information about your smartphone and how to set it up, as well as the pin for ejecting the SIM tray.

Unboxing the realme c21

Beneath the smaller box, you see the smartphone itself in a protective bag, and beneath the smartphone you find a USB cable and a standard 10W charger, without any fast-charging support. This smartphone being so affordable, realme has cut costs to the maximum and decided not to bundle a headset. An unsurprising decision if you ask us.

What you find inside the box

The realme C21 is a beautifully packaged product. Its box has only the basics you need to use your smartphone, and it doesn’t include a headset.

Design and build quality

The realme C21 is a standard-looking 6.5-inch smartphone with rounded corners. It has the following dimensions 6.50 x 3.01 x 0.35 inches or 165.2 x 76.4 x 8.9 mm. It is slightly larger and heavier than the realme 8 5G that we recently tested: realme C21 weighs 6.70 oz or 190 grams vs. 6.5 oz (185 grams) of the realme 8 5G. This smartphone is available in two colors: Cross Blue and Cross Black. We tested the blue variant.

The realme C21

The back of the smartphone is made of plastic, and it has an attractive striped texture that also helps with the grip. When you hold it in your hand, you don’t feel the smartphone slip. On the back, you find the camera system, the fingerprint sensor, the realme logo, and the phone’s only speaker.

The back of the realme C21

On the right side of the realme C21, you find the Power button and the Volume rocker.

The buttons on the right

On the left side, there’s only the SIM tray.

The SIM tray is on the left

On the top bezel, there is no jack or port.

The top bezel

On the bottom bezel, you find the microUSB 2.0 port, the microphones used for taking phone calls and noise reduction, and the audio jack.

The ports on the bottom bezel

When it comes to build quality, realme brags about this phone being the first to pass the TÜV Rheinland smartphone certification testing. The certification process involved 23 major tests:

  • ten daily use test scenarios, such as drop, wear and tear
  • seven extreme environment test scenarios, including super extreme temperature, extreme humidity, voltage fluctuation, button life, static electricity, and air pressure
  • six component reliability test scenarios.

While the realme C21 is made from plastic, it does feel well reinforced and quite solid, so this certification may not be just marketing talk.

Hardware specifications

The display uses an IPS LCD panel, with a peak brightness of 400 nits and 720x1600 pixels. The screen to body ratio is 80.8%, and the density is 270 ppi. If you want to know more about ppi and what it means, read: What is PPI and does it matter?.

Turning on the realme C21

The realme C21 is powered by a low-end MediaTek Helio G35 System on a Chip with four Cortex-A53 cores running at 2.3 GHz and another four at 1.8 GHz. The graphics chip is a PowerVR GE8320 that is well suited for multimedia applications but underwhelming for gaming. In terms of RAM, the realme C21 is available with both 3GB and 4GB, while the storage can be 32GB or 64 GB. We tested the variant with 4GB of RAM and 64 GB of storage, and we recommend you buy the same version to get the maximum performance possible from this phone.

The SoC inside the realme C21

Luckily, the storage can be increased with the help of a microSD card. Also, an upside is that you can use the phone with two SIM cards and a microSD card simultaneously. We expect many users to appreciate this feature.

realme C21 takes two SIMs and a microSD card

The non-removable Li-ion battery has a generous capacity of 5000 mAh, charging at 10W. As expected for a phone at this price range, there is no support for wireless charging built-in.

The realme C21 has a wide selfie camera in the middle of the screen with 5 Megapixels and an aperture of f/2.2. The main camera system on the back has three cameras:

  • A primary wide camera with 13 Megapixels, f/2.2 aperture, a 5P lens, and 4x digital zoom.
  • A 2MP macro camera with an aperture of f/2.4 and a 3P lens.
  • A depth of field 2MP camera, with an aperture of f/2.4.

There’s also a flash available for night photography. The main camera system can record videos in 1080p or 720p resolution at 30 frames per second. There’s no video stabilization available.

The main camera system on the realme C21

One issue is that the realme C21 works only with older wireless network standards like Wi-Fi 4. There’s no support for using Wi-Fi on the 5 GHz band, only the 2.4 GHz frequency. In our view, this is a significant limitation, and realme should have provided Wi-Fi 5 connectivity. Obviously, for a smartphone this affordable, there is no 5G mobile connectivity either.

realme C21 connects only to Wi-Fi 4

However, realme C21 does have Bluetooth 5 support, GPS, FM-radio support (if you buy yourself a headset). Also, it features a microUSB 2.0 port instead of a USB-Type C. In terms of sensors, it includes the following: an accelerometer, a fingerprint sensor, a proximity sensor, a light sensor, and a compass. Unfortunately, NFC support is lacking.

If you want more details about all the features and hardware specs, visit this page: realme C21 Specs.

Read the second page of this review for details about the smartphone experience offered by the realme C21, its cameras, operating system, and bundled apps, as well as its performance in benchmarks.

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