Comparative review : Samsung Galaxy M31s or Galaxy M51

This article presents a comparative review between two M series of Samsung Galaxy, Samsung Galaxy M31s or Galaxy M51 to find which one is better

When all media attention is focused on the most expensive, top Samsung devices – the Note line , folding Folds or Flips , the manufacturer is quietly chewing on the competition on the middle shelf. Prestige is prestige, but real money is made elsewhere, I do not know what the sales of the latest (otherwise amazing) Z Fold are , but I suspect that Samsung earns more on two smartphones reviewed today than in a month on its exclusive folder. The M line , which was conceived as a direct competitor to Xiaomi (and even more for the cheaper Redmi ) and the late Honor, it is relatively young, but already has very successful and well-priced models in its portfolio, such as the M21 . Anyway, Koreans have an advantage right from the start – as a manufacturer of AMOLED screens, they are able to offer them in virtually any price range.

Today we will look at two smartphones that share a difference of price . None of them support 5G, but otherwise they are well equipped, have quite powerful processors (especially the Snapdragon 730 looks attractive in the more expensive model), great displays, good optics and gigantic batteries. Also, the price, of course, by Samsung’s standards, is not too high. So let’s see if the competition has anything to fear.

How do we rate design? 

In both cases it is quite boring, but the middle shelf is not a place for sophisticated constructions and risky experiments. Practicality and low production costs count here, so plastic reigns supreme. Of course, catching fingerprints like crazy, in the tested copies the cheaper M31s is a bit more attractive, because the gradient black or blue backs look better than the one-color back of the M51(the manufacturer did not try to mention the names of the colors on the website, in my eye it is cream and black). The frame in both cases is made of plastic, and the arrangement of individual ports is identical – at the bottom there is a mini-jack input for headphones, USB-C and a single speaker (both quite loud and of good quality). On the right side – a fingerprint reader (still active and very fast), above it a button to adjust the volume. On the left side – a tray for two SIM cards plus an additional memory card. Personally, I am especially happy with the physical fingerprint reader – the screens in cheaper Samsung are simply poor, and everything is perfect here – and the location and operation. Alternatively, you can face unlock phones and this method works very well as well. I’m also happyM31s ).

The phones are quite large – the M51 is larger due to the larger battery. Its dimensions are 163.9 x 76.3 x 9.5 mm and the weight is solid 213 g. The dimensions of the M31s are 159.3 x 74.4 x 9.3 mm and the weight is 203 g. However, thanks to the rounded plackets they are quite comfortable in the hand and are quite comfortable to use – the upper bar can be pulled down with your thumb anywhere on the screen. So far, both phones are going head to head.

What do we think about the display? 

Both Samsung offers us Super AMOLED screens with FHD + resolution. The one in the M31s has a diagonal of 6.50 inches, 1080 x 2400 pixels and 405 ppi. M51it has a slightly larger display – 6.67 inches, 1080 x 2400 pixels and 395 ppi. There is a perfect draw in the quality of the displayed image, viewing angles, color saturation – both are just as good and it’s hard to find a weak point somewhere, especially at this price. We will not find 120 or 90 Hz refreshing in any of them – 60 Hz must be enough. And to be honest – it is enough if we cannot directly compare our phones with a device with higher refreshment, we will not complain about anything. The configuration options are the same – we have two screen modes – vivid and natural, and white balance – from cold to warm and RGB. It’s OK for this class of devices.

In both displays we have a centrally located selfie camera – in the cheaper model the hole has a silver border, but it looks smaller optically.

Neither one nor the other model has a notification LED, but the Always on Display, which, apart from the time and date, shows notifications from each application. We can also use the resources of the Galaxy Store and choose a theme that suits us.

Specs / OS 

Let’s start with the M31s model . It is powered by an octa-core Samsung processor- Exynos 9611 with Mali-G72 graphics chip. It has 6 GB of RAM to help, we have 128 GB of built-in memory with the possibility of expanding with a card (there is an additional slot, we do not have to give up dual-SIM). In AnTuTu Benchmark, the phone scored 190 061 points. In everyday operation, he performs decently – he is not a demon of speed or efficiency, but it is also difficult to complain about. This is a typical workhorse that does what it is supposed to do. From time to time you can catch him on some animation trim, a slight delay in response to our commands, but it won’t be anything to irritate us. It also handles games quite efficiently (tested on PUBG, Game Launcher in the settings), and when forced to work harder, it heats up quite clearly, but within reason.

In the M51 Samsung used a Qualcomm processor, the Snapdragon 730 with the Adreno 618 chip. It may not be the latest unit, it does not have a slightly overclocked graphics like the 730G, but it works very well. RAM is 6 GB, built-in memory – 128 GB (plus memory card and dual-SIM). In AnTuTu Benchmark, the phone reached 266,012 points. In everyday work I have nothing to complain about, personally this is a level of operation that would satisfy me on a private phone without any problems. It’s fast, smooth, responsive, no lag, and occasional clipping of the animation. In games, the phone is doing very well (PUBG) and most importantly, it does not heat up like Exynos in the M31s .

GPS works flawlessly in both phones, both have NFC, so we will pay with them contactlessly, and in both phones the quality of voice calls is also at a very good level. They both also have an FM radio, but Samsung’s own app for playing music must be downloaded from the Galaxy Store. Neither is waterproof.

The communication packages are also similar: LTE, WiFi 2.4 and 5 GHz, Bluetooth 5.0, NFC. Localization is done using: GPS, Glonass, BeiDou, Galileo in M31s , in M51 there are also QZSS and SBAS. The set of sensors includes: accelerometer, proximity, light, gravity, fingerprint reader, acc. To The specification in the M51 is still a magnetometer.

The system is Android 10 with One UI overlay. We have gestures, a dark theme, Game Launcher, Dual Messenger, i.e. support for two accounts in one application. Everything is presented in a nice and clear way.

What kind of photos does he take and what films does he record? – rating 4 ( M31s ) / 5 ( M51 )

The camera set in both devices is almost identical. This is the main lens 64 MP, f / 1.8, PDAF; wide angle 12 MP, f / 2.2, 123˚ and twice 5 MP, f / 2.4 – macro and depth sensor. In the front we have 32 MP, f / 2.2. The only difference in the numbers is the 2.0 aperture instead of 2.2 in the M51 selfie camera .

However, those who think that the photos will also be identical would be wrong. Here, we can clearly see how important the processor is and why Snapdragons dominate Exynos in this field as well. Because the photos from the M51 are better than those from the M31s . Although maybe I should start with the fact that in general the photos from both are of a very good standard (with one small exception). So in both we have very nice, saturated colors (slightly warmer in the M51), excellent tonal range, great HDR, nice details and at first glance a slight difference between the main lens and the wide angle (only when you zoom in you can see less detail). There is no optical zoom in both, the digital zoom is 10x and roughly up to 5x it’s pretty good quality. Macro photos are similar, i.e. rather average. The difference is only in the night photos – neither one nor the other phone is a champion in this field, but while the photos from the M51 may still be liked, the ones from the M31srather not. As if the phone could not cope with the imposition of individual frames, which in turn translates into less details and worse sharpness. The photos are also darker than those of the more expensive model. Despite these disadvantages, it must be remembered that many more expensive competitors’ phones are not able to provide the same quality of photography as these two devices.

We can record video in 4K and lower resolutions, electronic image stabilization works well, also in 4K, but the cheaper model had obvious problems with keeping sharpness. The amount of detail and fluidity are at a very good level.

Sample photos of the  Samsung Galaxy M31s & Samsunga Galaxy M51

Samsung Galaxy M31s closeup
Samsung Galaxy M51 Close-Up
Samsung Galaxy M31s
Samsung Galaxy M51
Samsung Galaxy M51
Samsung Galaxy M31s image at night

How long does the battery last? – grade 6

6000 mAh in M31s and 7000 mAh in M51 are perfect, of course the latter model is better due to the larger capacity of the cell and the processor with less energy consumption. But even so, two days of work on one charge is a minimum, depending on what we do and how often we reach for the phone, we will be able to reach up to 4 days, with a minimum of 8 hours on the screen on the M51 and an hour less on the M31s . Both models support chargeback. The chargers have 25W, and the full battery charge takes less than 2 hours.

Our final assessment

Both models are successful, quite similar devices. I would personally pay extra for the M51 . Better work culture, quality of photos or longer battery life are in my opinion worth PLN 200. But also the buyers of the M31s will not be disappointed, the phone works smoothly, has an excellent screen, takes great photos and is also slightly but smaller, and therefore more convenient to use.

Another thing will be to match these phones with competitors’ devices. Paying a little more, we can already have a Motorola G 5G Plus that supports 5G bands and has a better processor, although the price is a worse screen. For this price range, we will get Mi 10 Lite 5G – with an AMOLED screen, better processor and 5G support. If we do not want 5G, we have a choice of many devices that are better priced than Samsung, including realme 7 Pro or Mi Note 10 Lite .

Who are the Samsung M31s and M51 for :

  • Lovers of good photos in the middle shelf
  • People who require a long working time on a single charge
  • People who like beautiful screens
  • People who need good quality sound from headphones

Who are not Samsung M31s  and  M51 :

  • Small phone lovers
  • Demanding the highest quality of workmanship
  • Need inductive charging and waterproof
  • Needing stereo speakers

The main pros and cons of the Samsung Galaxy M31s and the Samsung Galaxy M51

Advantages of the Samsung Galaxy M31s :

  • Perfect screen
  • Giant battery
  • Good action
  • Mini-jack input for headphones
  • Convenient fingerprint reader
  • AOD showing notifications from all apps

Disadvantages of the Samsung Galaxy M31s :

  • Plastic housing
  • Poor quality of photos at night
  • External mono speaker
  • Problem with keeping sharpness while shooting movies
  • The processor heats up with a stronger load

Advantages of the Samsung Galaxy M51 :

  • Perfect screen
  • Giant battery
  • Very good performance
  • Mini-jack input for headphones
  • Convenient and fast fingerprint reader
  • AOD showing notifications from all apps

Disadvantages of the Samsung Galaxy M51 :

  • Plastic housing
  • External mono speaker