Test Reviews
Samsung Galaxy A21s test / review
Published on: 01-08-2020 / Modified: 08-11-2021
After testing several Chinese brands, I decided to make a come back to Samsung by buying the Samsung Galaxy A21s. What motivated me to buy this phone is mainly the price because it falls into the same price category as the latest models from Xiaomi that I tested.
Samsung has always been more expensive than Xiaomi and the price/performance ratio was always in favor of Xiaomi. I wanted to see if things had changed.
The Samsung Galaxy A21s is priced on par with the Redmi Note 9s but seems to be more in competition with the Redmi Note 9.
My test will show whether the price difference is justified and how the Samsung Galaxy A21s can compete with its Chinese competitor.
Structure of my tests
I test the phones according to a pre-established structure (see below) to provide you with as much information as possible. Unfortunately, this takes a long time. Some tests like network performance tests take several days and for photo tests I sometimes have to wait until the weather is suitable to take pictures in good conditions. I am therefore obliged to publish the tests step by step, so I invite you to come back if the test is not complete at the time of your visit.Price Samsung Galaxy A21s
The list below shows the prices for the Samsung Galaxy A21s from more than 50 sites around the world. If you are not satisfied with any price, you can subscribe to a price alert to be the first to be notified when the price drops.The above links are affiliate links from companies such as Amazon, Gearbest, Aliexpress,... If you appreciate my work, I would be grateful if you could purchase these products through these links. It costs you absolutely nothing but I get a small commission that allows me to buy the material I test. Thank you very much!
Timeline
July 2020: purchase of the Samsung Galaxy A21s on RueDuCommerce with trade-in pack01/08/2020: I start the test with a little delay because I had a lot of other devices to test.
Why this phone?
As I wrote above, it was the price that motivated me to buy this phone and it will probably be the case for many buyers as well. If you are not ready to buy a Chinese brand yet, this Samsung will surely be one of the first choices for buyers who don't want to pay more than 200€ for their phone.Beside the price I also look at other elements that show that in theory this Samsung can't compete with the Redmi Note 9s but the test should be able to show if this is really the case. It is clearly a match between the Samsung entry-level versus the Xiaomi entry-level.
Unpacking
The Samsung Galaxy A21s comes in a classic white box containing the phone, charger, USB cable, earphones and manual.
In the same price range, Xiaomi offers in addition a transparent protection but does not offer earphones. Those who want to protect their smartphone against scratches will therefore have to buy an extra protection.
First configuration
The configuration of the Samsung has changed in recent months and this is not a good thing. Samsung now requires the use of an application called Smart Switch to transfer data from the old phone to the new one. So you still need to have the old phone to install the application. I find this kind of process completely useless and superfluous. Android is linked to a Google account and this Google account allows you to transfer and synchronize data across multiple devices. Smart Switch is an attempt by Samsung to access this data which is usually only accessible through the Google account.At the end of the startup procedure, the phone will propose a screen to create a Samsung account, it's a fairly common practice but even refusing, Samsung will try to force the installation of some applications two screens later.
The Samsung Galaxy A21s has only 32Gb of data, it's been a long time since I've had a phone with so little storage memory. So I had to make a choice in what I wanted to copy from my old phone which had 64 Gb because the storage capacity of the Samsung did not allow me to transfer everything.
Finish
The Samsung Galaxy A21s is an entry-level phone but the finishes are correct, the backside sags a bit when you press it but Samsung is used to making phones with a good level of finish in all price ranges. In this price range, it is possible to find phones with a glass back that offer a better finish but this doesn't change anything to the use of the phone, it's a rather subjective choice.
The Samsung Galaxy A21s is an entry-level phone but the finishes are correct, the backside sags a bit when you press it but Samsung is used to making phones with a good level of finish in all price ranges. In this price range, it is possible to find phones with a glass back that offer a better finish but this doesn't change anything to the use of the phone, it's a rather subjective choice.
The lower part of the phone has a very classic configuration with a USB type C port, a mono speaker and a jack socket for the headset.
The volume and start buttons are located on the right side of the phone, the position of these buttons is similar to what is found on most phones today. The buttons are made of plastic, they don't stick out very strongly from the device but they are separated by enough space to be able to distinguish them. The SIM drawer is on the left side.
The back of the phone is almost perfectly smooth, it is only interrupted by the photo module which does not stick out much. Xiaomi tends to use photo modules that come out of the phone quite strongly, Samsung is better off.
The Samsung Galaxy A21s has a large 6.5-inch screen and an occupancy rate of 82%, a border is visible all around the screen with a slightly thicker border at the bottom of the screen. The A21s is quite similar to what I was able to test at Xiaomi both in screen size and screen occupancy percentage. These borders are not annoying and the screen size offers a comfortable experience.
The camera for the selfies is housed in the top left of the screen, it appears as a black dot on the screen but it never bothered me in the use of the phone, the black dot is quite discreet.
Specifications
The information below comes from the Device Info HW application. The application provides detailed technical information about the tested phone.I bought the 3Gb version with 32 Gb of storage. There is another version with 4Gb and 64 Gb of storage.
I don't advise to buy a 32Gb version because even if you don't use a lot of applications, the lack of space will quickly force you to clean the phone.
CPU / GPU Performance
The Samsung Galaxy A21s is equipped with an Exynos 850 processor, it is an entry-level processor that offers lower performance than the Snapdragon 665. The processor is clearly not the strength of this phone and this is also felt in use. My opinion is obviously a bit biased because I'm used to testing more powerful phones and the difference is obvious. If on the other hand you have always bought entry-level phones, you probably won't feel this lack of reactivity as much. Of course, this does not prevent you from using the phone, it is first of all a question of comfort.
Benchmark Antutu/3DMark
As I wrote above, the Samsung Galaxy A21s is not a performance brute and even if you are not a gamer, this lack of performance is felt when using the phone at every screen change or application launch.I got a score of 123,000 points on Antutu, this is one of the lowest scores I've gotten so far. In this price range there, Samsung's positioning is therefore not very good. With a price of 199€, it's possible to buy a Redmi Note 9s which scores 270 000 points on Antutu. So the price/performance ratio is really not good at Samsung.
Gaming
To test the performance in game, I download the mobile PUBG game and evaluate the in-game experience, graphics level and depth of vision. This game is quite demanding and should help you evaluating the performance of a phone.
The Samsung Galaxy A21s is not a phone for gamers but it allows you to run PUBG Mobile with a few sacrifices. The game works but the animations are jerky and the fluidity of the game is not always optimal. The screen resolution of the A21s is lower than average which allows the games to require less processing but this is at the price of a slightly degraded visual experience.
Network performance
The Samsung Galaxy A21s, like most Samsung phones, offers comprehensive coverage that will allow you to use the phone anywhere in Europe. The B28 frequency for Bouygues and Free in France is also available.Signal 4G (before december 2020)
The ability to pick up the network correctly is an essential element for a phone but it is only very rarely measured. To measure a phone's ability to pick up the network, I perform a large number of measurements on the same cells to be able to compare phones under similar conditions. The signal is measured in dBm, a value of -90dBm indicates a worse signal than -70dBm. These measurements are therefore taken under real conditions and not in a laboratory, they are not scientific but give a good indication of performance.
Out of 1000 measurements I got an average signal of -97.78 dBm with the Samsung Galaxy A21s where I got -99.4 dBm with a Redmi Note 9s under the same conditions. The Samsung Galaxy A21s picks up the network better than the Redmi, this is not a surprise as it is a weak point of the Redmi range.
The Samsung's score is a bit above average, it exceeds most of the Redmi I tested.
Signal 4G (from December 2020)
I decided to change the methodology for measuring the network because I noticed that the configuration of the mobile network changes over time. This makes it more difficult to compare phones because the conditions are no longer exactly the same.
To overcome this problem, I set up a device that captures 24 hours a day about ten parameters from the mobile network (ex: cell id, rssi, rsrq, snr, frequency,...). I then place the phone next to the device for 24 to 48 hours taking the same measurements so that I can compare them.
Overview of the phones tested with this methodology
Download/Upload speed
To test the download speed, I have identified some 4G cells offering good performance where I test all my devices several times to see what download and upload speed they can achieve.
I got a 4G download speed of 147 Mbps which puts the A21s in the good average of the phones I tested. The network is probably limited to 150 Mbps but this Galaxy A21s will allow you to stream in HD without any problem.
Wifi performance
To test a phone's ability to receive the network properly, I take measurements near my router and then remotely (and always at the same place). This gives me an average in dBm where a value of -90 dBm indicates poorer performance than a value at -30 dBm.Wifi signal
I got a signal of -13 dBm near the router, this is one of the best score I got which shows that the Galaxy A21s has a very good wifi sensitivity.
I measured a signal of -70 dBm away from the router, this is also a very good score.
Download/Upload speed
To test the speed in Wifi, I connect to my router in 2.4Ghz and 5Ghz (if available) and use the Ookla application to measure the speed.I got a maximum speed of 165 Mbps in download, it's a good score that allows to stream in HD but it's below the average of what I got with other phones in the same conditions.
GPS performance
To test the quality of the GPS signal I use the Offline Maps application and I make the same train trip in pedestrian mode. Why? In pedestrian mode, the GPS does not artificially correct the signal to stick to the road, it has no markings, so you can see the actual position. I then use an application to measure the accuracy of the signal.
The Samsung Galaxy A21s captures most common GPS networks (GPS,Galileo,Baidou,...). I obtained an accuracy at 4 meters which fluctuate regularly between 4 and 6 meters. This is clearly not the best score I got and the lack of power of the phone may also create a discrepancy between the actual position and the displayed position.
Battery range
[battery product="samsung-galaxy-a21s" capa="5000" lg="en"]The Samsung Galaxy A21s has a 5000 mAh battery that will give you a very comfortable autonomy of several days in normal use.
Charging the Samsung is quite fast, I recharged the battery from 1% to 100% in 166 minutes, it's about the same as the Redmi Note 9.
The battery capacity allows to last several days but the phone could have been more efficient because at equal capacity, other phones do much better. In particular, the Redmi Note 9 lasts 500 minutes longer with the display on at 50%.
Photo camera test
To test the quality of photos produced by a phone, I do a technical test (resolution, sharpness, chromatic aberration,...) in studio (identical conditions) to evaluate the technical part objectively. From the second half of 2020, I built my own laboratory to take completely objective technical measurements. I then take pictures in real conditions to see how the camera performs. I then evaluate these photos according to my criteria but I publish the photos so that you can evaluate the result according to your criteria.Hardware
The Samsung Galaxy A21s is equipped with a 48 million pixel Samsung S5KGM2 main sensor which is also used in the Redmi Note 9, the Redmi Note 8 and the Samsung Galaxy A51.This sensor has already proven itself on other phones, so it is the image processing provided by Samsung that can make the difference with other brands.
Default app
Samsung has made the choice of simplicity with its photo application. Where Xiaomi seems lost in a race for complexity, Samsung has chosen to limit the entry points to the bare minimum by placing the least used features behind a separate menu.
The photo application therefore offers by default an entry point for photo, video, portrait mode and everything else can be found in a sub-menu containing a pro mode, panorama mode, macro mode and food mode.
Since most users of this type of phone will be satisfied with the basic features, Samsung has probably made the right choice. Samsung also had the good idea to divert the icons to change the sensor, this makes them much more readable than with Xiaomi.
Photo quality
Photo test / studio
Main sensor
Exposure: good
Sharpness: good
Colours: good
Depth of field: good
Distortion: none
Chromatic aberration: none
Vignetting: none
Digital noise: none
Samsung sensors usually do less well than Sony sensors under artificial studio lighting, fortunately there are exceptions and this Samsung S5KGM2 sensor does a good job. The photo is properly exposed, the colors are natural even if they could have been a little brighter. The sharpness is good and the photo has no particular defects. I had not obtained such a good result with the Redmi Note 9 which applied an incorrect treatment on the colors.
Ultra wide angle sensor
Exposure: underexposure
Sharpness: medium
Colours: too dark
Depth of field: good
Distortion: important
Chromatic aberration: none
Vignetting: none
Digital noise: none
The wide-angle sensor captures a very wide image, it's one of the widest sensors I've tested so far. So it has the advantage of capturing very close subjects but the distortion is very important. Usually the distortion is mostly visible in the periphery but here we see that the Statue of Liberty is thinner, the figure on the right is abnormally curved, the rest of the picture follows my same tendency. The exposure time is not good either, the photo is globally too dark and this is quite often the case for wide angles when there was enough light to increase the exposure time without risking to make a blurry photo.
This first technical test is promising for the future, the main sensor produces a better result than other phones that use exactly the same sensor. Samsung has an undeniable know-how in photo processing.
Photo test / sunny
Main sensor
Exposure: good
Sharpness: good
Colours: good
Depth of field: good
Distortion: none
Chromatic aberration: none
Vignetting: none
Digital noise: none
When conditions are good the main sensor of the Galaxy A21s is able to produce beautiful, richly saturated photos with a dynamic range that can display dark and bright areas without falling into over/under exposure. Image sharpness is also good without being forced, leaf detail is clearly visible.
Ultra-wide-angle sensor
Exposure: good
Sharpness: good except on the sides
Colours: good
Depth of field: good
Distortion: visible in the periphery
Chromatic aberration: none
Vignetting: none
Digital noise: none
The ultra-wide-angle sensor produces better pictures outdoors, especially when it comes to open landscapes like this one. Sharpness decreases as you move away from the center, it's quite visible on the foliage on the left. It is therefore always necessary to take care to have the main subject close to the center otherwise it may end up in a blurred area with significant distortion. I am positively surprised by the color treatment because it is very similar to what I obtained with the main sensor.
Main sensor
Exposure: good
Sharpness: good
Colours: good
Depth of field: good
Distortion: none
Chromatic aberration: none
Vignetting: none
Digital noise: none
I took another picture made with the main sensor to show the level of detail and richness of colors when the scenery is closer. The foliage detail is very good and despite the dominance of dark colors, the sky does not lose saturation. I see a slight blur in the treetops but you have to zoom to more than 100% to see it.
Ultra wide angle sensor
Exposure: good
Sharpness: good except on the sides
Colours: good
Depth of field: good
Distortion: visible in the periphery
Chromatic aberration: slight
Vignetting: none
Digital noise: none
The ultra wide angle sensor performs better than sensors of this type on other brands such as Xiaomi. The distortion is visible but not problematic for landscapes, the colors are well saturated and the exposure time is good. With closer scenery elements, the distortion is more visible and the blur area is even very large in the upper left corner of the picture. The tops of the trees seem to have been over-treated because I can see a thin white net surrounding the leaves.
The following pictures confirm the findings made on these first pictures. I knew that this sensor was capable of producing good pictures because I had been able to test it in other phones, but Samsung managed to apply quality processing to the images which allows the Galaxy A21s to move up a notch above other phones using the same sensor.
Photo test / cloudy
Main sensor
Exposure: slightly underexposed
Sharpness: good
Colours: slightly too dark
Depth of field: good
Distortion: none
Chromatic aberration: none
Vignetting: none
Digital noise: none
Under an overcast sky, the Galaxy A21s manages to reproduce the atmosphere well, the difference in exposure between light and dark areas is quite important but the phone manages to manage the differences well. The picture is a little too dark, the colors too but it's a good result in this price range.
Ultra wide angle sensor
Exposure: underexposed
Sharpness: good
Colours: too dark
Depth of field: good
Distortion: in the periphery
Chromatic aberration: none
Vignetting: none
Digital noise: none
The ultra wide angle sensor always captures less light than the main sensor and this is very visible in this picture. The photo is significantly darker even though it was taken a few seconds apart from the first photo. The distortion is visible on the side, the sharpness is also strongly degraded on the sides. This sensor does not perform as well under these conditions, and in addition, always make sure to have the main subject in the center to avoid falling into the peripheral blur area.
Pictures in cloudy weather are not extraordinary but they are quite correct for this price range. I can hardly criticize the result because even if these pictures are not perfect, this sensor allows me to capture the atmosphere of the scenery realistically enough.
Test photo / night
Main sensor
Exposure: correct
Sharpness: medium
Colours: too cold
Depth of field: good
Distortion: distortion and blurring at the periphery
Chromatic aberration: none
Vignetting: none
Digital noise: visible
The Samsung Galaxy A21s does not have a night mode, so the photo does not benefit from any special treatment. Night photography is clearly not a strength of the Galaxy A21s, the sharpness is very average, some areas are even blurred, light halos are not corrected, colors are a bit dull and digital noise is visible. In the same price range, we find phones that are able to do much better using the same photo sensor.
Ultra wide angle sensor
Exposure: underexposure
Sharpness: bad
Colours: too warm
Depth of field: not sufficient
Distortion: distortion and blurring at the periphery
Chromatic aberration: none
Vignetting: none
Digital noise: visible
Ultra wide angle sensors are not designed to take pictures at night and this is once again true with this phone. The photo is a little sharper in the center but the whole periphery is blurred.
Video quality
Stabilisation
The Samsung Galaxy A21s does not have video stabilisation, vibrations and shocks will not be corrected. I haven't found a phone with good stabilization in this price range yet, so the Samsung is neither better nor worse than other phones in this price range.
Video normale conditions
The Samsung Galaxy A21s is capable of producing good videos when the light is good. Sharpness is good, colours are richly saturated and sound is well reproduced. The weakness of the Galaxy A21s is its lack of power and this is felt a little for videos because the recalculation of pixels during movements or changes in exposure is quite visible. The video processing is a bit too slow but this problem is only visible with important movements or brightness changes.
Video low light
The Samsung Galaxy A21s produces fairly average videos at night. The video should have been exposed a little more and the focus makes visible back and forth between the different elements of the video. When the scenery is too dark, it can't be fixed in one place. The digital noise is quite visible too.
In this price range, the Redmi Note 9s does better.
Audio quality
To test the quality of the phone's audio output, I connect the device's audio output to a measuring tool, then play sounds on all frequencies and measure the differences between the original sound and the sound produced by the phone. In this way I measure the phone's ability to correctly reproduce all sounds.In this price range, you should not expect to find a phone with outstanding audio performance, most phones offer good sound without being exceptional.
The Samsung Galaxy a21s is no exception. The sound produced by the speaker is of average quality, the sound is not very powerful either.
With a headset the sound is of better quality and offers more power.
Frequency Response
This test is intended to test the device's ability to correctly reproduce all frequencies. The white line in the middle of the graph is the ideal situation and the other colors come from tests on different phones. A deviation from the reference line indicates a deviation from the ideal situation. To see good sound at all frequencies, it is therefore necessary to get as close as possible to the reference line.
I compared the Samsung Galaxy a21s with the Redmi Note 9 to see which phone reproduced the frequencies more correctly. In the low frequencies it is the Redmi that is the most faithful and in the high frequencies it is the Samsung that is the most faithful. However, you have to be really careful to perceive the difference, it will also depend on the type of music. As a whole the A21s offers a good reproduction of frequencies but to find better it is necessary to pay more expensive.
Dynamic Range
This test is designed to test a phone's ability to play sounds at different volume levels. Here too, the phones must be as close as possible to the reference.
The Galaxy A21s manages to produce a correct sound on all frequencies by offering much more power than the Redmi Note 9, this power is not very well controlled because at maximum volume the distortions are more important. So you have to lower the volume by 2 or 3 steps to get a better sound quality.
Noise Level
This test aims to identify if the device under test is able to reproduce sounds without too much noise. A high score indicates a low parasite rate, a lower score indicates a higher presence of parasites.
The Galaxy A21s is capable of reproducing sound without interference, and it does much better than the Redmi Note 9 even if it is difficult to perceive the difference to the ear.
Screen quality
To test the screen, I use a colorimetric probe that measures the color accuracy of a screen, as well as other parameters to see if a screen is able to correctly reproduce an image. I also test the brightness level to determine if the screen will be able to display an image in full sunlight.Colorimetry
Samsung generally produces good displays but this rule does not seem to apply to entry-level models. The Galaxy A21s has a color difference dE of 7.2, which is quite far from what I can get with a Redmi Note 9s for the same price. What does this mean? If you compare the screen of the Samsung with a screen like the one of the Redmi Note 9s, you will see a visible color difference. The Galaxy A21s deviates from the standard especially in the green area.
The screen is quite large but is limited to a resolution of 720x1600 where we usually find a resolution of 1080x2400 pixels on other phones of the same price. Using fewer pixels on the same surface means a less detailed image.
Brightness / Contrast
I measured a brightness of 440 cd/m², this is a good score that should allow you to use this phone in almost any condition but there are many phones today that can produce much more light. This can be felt in bright sunlight where 440 cd/m² may be slightly insufficient for good readability.
I measured a contrast ratio of 1350:1, which is an average score for this type of screen. Once again the Redmi Note 9s does better for the same price.
Biometry
The Samsung Galaxy A21s is equipped with a fingerprint sensor on the back, this sensor is fast and efficient. It also works better than most on-screen sensors. The 2D facial recognition also works well.Operating system
The Samsung Galaxy A21s benefits from Samsung's know-how for its operating system. Samsung UI is undoubtedly one of the most advanced operating systems on the market. If you come from a basic Android version, the adaptation time will be minimal.Encoutered bugs
Not yet available / testedAccessories Samsung Galaxy A21s
Compare Samsung Galaxy A21s with the others
Test / Review conclusion
Not yet available / testedStrengths
Daylight photo/video quality
Battery life
Signal wifi/4G
Operating system
Weaknesses
Low performance
Screen colorimetry
Alternatives to this product
In the same price range, I rather recommend the Redmi Note 9s which outperforms the A21s in most areas except for daylight photography and 4G network sensitivity.
LAURENT WILLENHead of myself on this blog
I share my passions on my blog in my free time since 2006, I prefer that to watching nonsense on TV or on social networks. I work alone, I am undoubtedly one of the last survivors of the world of blogs and personal sites.
My speciality? Digital in all its forms. I have spent the last 25 years working for multinationals where I managed digital teams and generated revenues of over €500 million per year. I have expertise in telecoms, media, aviation, travel and tourism.
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