❤ Samsung Galaxy A51



If 2019 taught us anything it’s that Samsung‘s A-series span pretty much the entire spectrum of feature sets and price brackets short of a true flagship. The 2020 roster is only beginning to unfold and the company kicked things off by adding 1s to product names in the mid-tier – thus the Galaxy A51 was born.






That 1 means a lot when you look at the A51 and A50 side by side. For starters, there’s 1 more camera on the new model – a close-focusing 5MP shooter. The chipset is also “1” better – the A51 is powered by the Exynos 9611 as opposed to the 9610 in last year’s phone. And then a 0.1-inch increase in screen diagonal continues the theme albeit at a lower order of magnitude.





Let’s put our lame attempts at numerology to the side, and mention the other upgrades that the Galaxy A51 brings – almost exclusively in the camera system. There’s a 48MP Quad Bayer primary unit now replacing the 25MP conventional module of the A50 and the ultra wide-angle cam’s sensor has grown in pixel count – it now stands at 12MP as opposed to the A50’s 8MP, still with 123-degree coverage.





And you be the judge if this counts as an upgrade, but the selfie camera now sits in a cutout in the top center of the display, unlike the A50’s notch. Infinity-O replaces Infinity-U. The camera itself should, indeed, qualify as an upgrade – a 32MP Quad Bayer unit where the A50’s 25MP snapper used to sit.

Samsung Galaxy A51 specs

  • Body: Glass front (Gorilla Glass 3), polycarbonate back and frame.
  • Screen: 6.5-inch Super AMOLED, 20:9, FHD+ (1080x2400px), 405ppi.
  • Rear camera: Primary: 48MP, 1/2″ sensor size, 0.8µm pixel size, 26mm equiv. focal length, f/2.0 aperture. Ultra wide angle: 12MP, 1.12µm, 13mm, f/2.2. Macro: 5MP, 25mm, f/2.4. Depth sensor: 5MP, 1/5″, 1.12µm, f/2.2. LED flash; 2160p@30fps video recording.
  • Front camera: 32MP, 1/2.8″, 0.8µm, 26mm, f/2.2. 1080p@30fps video recording.
  • Chipset: Exynos 9611: octa-core CPU (4×2.3 GHz Cortex-A73 & 4×1.7 GHz Cortex-A53), Mali-G72 MP3 GPU.
  • Memory: 4/64GB, 4/128GB, or 6/128GB versions, UFS 2.0; dedicated microSD slot for up to 1TB expansion.
  • OS: Android 10; Samsung One UI 2.0.
  • Battery: 4,000mAh, 15W charging.
  • Connectivity: Dual SIM (4G), Bluetooth 5.0, Wi-Fi a/b/g/n/ac, USB-C; 3.5mm audio jack.
  • Misc: Under-display fingerprint reader, single bottom-firing loudspeaker.

Samsung Galaxy A51 unboxing

There’s no ‘New year, new me’ when it comes to the A-series presentation and the Galaxy A51 arrives in a familiar white box with a glossy print of the phone on top, a cutout with the model numbers helping identify what’s inside.





And inside, sure enough, you’ll find the Galaxy A51. Besides the phone, you’ll be getting a 15W power adapter – the tried and tested QC2.0-based Samsung Adaptive Fast Charging unit, plus a USB-A-to-C cable to complete the link. A basic set of earbuds is also part of the bundle, but there’s no protective case – other makers take the exact opposite approach, and we’d probably pick a case instead of a headset, but to each their own.


The Galaxy A51 and A71 that got announced at the start of the year usher in Samsung‘s new language when it comes to rear camera design. Like it or not, oversized rectangular clusters in the top left corner that group all shooters under the same roof is how the company’s phones will adapt to the ever growing number of modules. The Galaxy A51 we have here, packs a total of four cameras on its back.




The assembly is raised by about a millimeter, but that doesn’t make it particularly prone to wobbling, if that’s a concern to you. The flash also found room with the cameras, and with a fingerprint reader missing on the back, the camera bump is the one thing that breaks the back panel’s continuity.





Samsung designers figured an accent is then in order, and spiced things up with a rather unique finish. A seemingly arbitrary diagonal line separates a fine-striped bottom part from the solid top, while another diagonal line divides the back into a darker and a lighter portion. The two diagonals intersect, forming an ‘X’ of sorts with four different resulting quadrants.





And that’s before the phone starts playing with light. Our Prism Crush Black review unit explodes in an entire rainbow of colors if you look at it under the right angle. Going by the official renders, we can see a hint of that rainbow regardless of the colorway. We do like the look, though if it were up to us, we’d pick one of the brighter colors.





For all its good looks, the Galaxy A51‘s back panel is made of plastic, so we wouldn’t trust it to be too durable – a sheet of Gorilla Glass would have inspired a bit more confidence. The front does get some of Corning’s 3rd-gen glass, so at least your display should be safer.

It’s an Infinity-O panel that sits on the A51‘s front, meaning a mostly bezelless and notchless display, but with a tiny circular cutout for the selfie cam. It’s a look that we’re familiar with from the Note10s of this world and it’s apparently another one of the company’s signature touches for the time being.





As for the bezels, the A51 is a noticeable step up from the A50, with the chin now being a lot thinner. The top and the sides are even slimmer, but more importantly they’re the same thickness too, which should please those of you that pay attention to small details. As was the case with the A50, the Galaxy A51 has a slit up top for the earpiece, carved into the glass.





The phone’s frame is made of plastic, same as last year, and much like the A50, the A51‘s physical buttons are all on the right – what was the point of the whole ‘buttons on the left’ switcheroo we saw on the Note10? The buttons themselves have decent travel, but they do click a bit less satisfyingly if you press them off-center.





On the left side of the phone, way up towards the top, you’ll find the card tray. On our dual SIM review unit, it’ll take two nano SIMs and a microSD all at the same time so you don’t have to pick between extra storage and an extra SIM.

Down on the bottom, there’s the USB-C port in the center. A headphone jack sits on one side, the loudspeaker and the primary mic on the other. Up top there’s another mic and that’s about it.





The Galaxy A51 measures 158.5×73.6×7.9mm and weighs 172g making it one of the more pocketable offerings in the segment. It’s thinner and narrower than the Realme X2 and competing Xiaomis (the Mi 9T and Redmi Note 8 Pro, to name a couple) and it’s also lighter while still packing a 4,000mAh battery. It is, in fact, surprisingly slim and light in the hand.





6.5-inch Infinity-O Super AMOLED

The Galaxy A51 has a 6.5-inch Super AMOLED display with 1080 by 2400 pixels in a tall-for-a-Samsung 20:9 aspect ratio. It’s an Infinity-O panel, meaning it’s got a punch hole for the selfie camera, as opposed to a notch of any sort or shape. The A51 and A71 were the first non-flagships in the company’s lineup to adopt that approach, with the Lite S10 and Note10 following.





Infinity-O or otherwise, it’s still a Samsung OLED display and behaves in much the same way we’ve come to expect from those. We measured a maximum brightness of 636nits when the Adaptive brightness toggle was engaged and 413nits if you take over control of the slider. Minimum brightness was 1.8nits.


Display test 100% brightness
Black,cd/m2 White,cd/m2 Contrast ratio
Samsung Galaxy A51 0 413
Samsung Galaxy A51 (Max Auto) 0 636
Samsung Galaxy A50 0 424
Samsung Galaxy A50 (Max Auto) 0 551
Xiaomi Mi 9T 0 449
Xiaomi Mi 9T (Max Auto) 0 646
Realme X2 0 432
Xiaomi Redmi Note 8T 0.331 450 1360:1
Xiaomi Redmi Note 8T (Max Auto) 0.453 600 1325:1
Xiaomi Redmi K30 0.399 550 1378:1
Xiaomi Redmi K30 (Max Auto) 0.527 714 1355:1
Xiaomi Redmi Note 8 Pro 0.347 460 1326:1
Xiaomi Redmi Note 8 Pro (Max Auto) 0.486 640 1317:1
Nokia 7.2 0.371 498 1342:1
Nokia 7.2 (Max Auto) 0.421 585 1390:1
Honor 9X 0.361 464 1285:1
Motorola Moto G8 Plus 0.317 477 1505:1
Motorola Moto G8 Plus (Max Auto) 0.395 581 1471:1


Color rendition is handled familiarly – the Natural/Vivid approach Samsung introduced recently. Natural aims to reproduce sRGB content truthfully, and we measured a very good average deltaE of 1.8, though 100% Green was particularly off with a deviation of 5.4.

The Vivid mode offers a 5-position cool-to-warm slider, and we were particularly impressed with the spot-on whites and grays at the warmest setting, which yielded an overall average deltaE of 2.7 when examining color swatches against their DCI-P3 targets. The mid-point on the slider will get you slightly worse average deltaE of 3.3 and not as accurate whites – moderately shifted towards blue to the tune of a deltaE of 4.

Samsung Galaxy A51 battery life

The Galaxy A51 has a 4,000mAh battery inside, same capacity as the model it replaces and pretty much par for the course in the segment. Despite using the same chipset, the A51 does come with a slightly larger display and a different OS, so we expected at least some difference in the battery life, and indeed that’s what we got.

We clocked 13 and a half hours on the web over Wi-Fi, a full hour more than what the A50 managed. Then again, we’re witnessing an hour and a half drop in video playback to 14:22h – still a respectable number. The 22-hour call time isn’t spectacular, but it’ll do. In the end, the Galaxy A51‘s overall Endurance rating adds up to 86 hours.





Using the supplied adapter, the Galaxy A51 charges from flat to full in 2:14h, which won’t win it any contests, but is fairly decent. At the 30-minute mark, we were looking at 35%, and that too isn’t praiseworthy.

Audio quality

Next up – testing the quality of the output through the audio jack. The Samsung Galaxy A51 put in a spirited performance with an active external amplifier, getting top marks while maintaining downright impressive loudness.

The volume remained high with headphones, and we got a bit of extra distortion and a moderate amount of stereo crosstalk. All things considered, it’s an excellent showing by the mid-ranger, though.

Test Frequency response Noise level Dynamic range THD IMD + Noise Stereo crosstalk
Samsung Galaxy A51 +0.03, -0.05 -93.1 93.1 0.024 0.041 -87.3
Samsung Galaxy A51 (headphones) +0.13, -0.19 -93.2 93.2 0.131 0.193 -53.8
Samsung Galaxy M30s +0.03, -0.05 -93.7 93.5 0.0008 0.0078 -93.2
Samsung Galaxy M30s (headphones) +0.17, -0.26 -93.0 92.9 0.075 0.248 -54.9
Redmi Note 8 +0.02, -0.02 -94.0 94.0 0.0019 0.0067 -93.3
Redmi Note 8 (headphones) +0.35, -0.26 -91.3 90.9 0.015 0.445 -45.4
Motorola Moto G8 Plus +0.02, -0.01 -93.2 93.2 0.0017 0.051 -94.2
Motorola Moto G8 Plus (headphones) +0.02, -0.01 -93.1 93.0 0.0035 0.037 -83.8
Realme X2 +0.03, -0.06 -92.6 92.6 0.0020 0.0080 -88.1
Realme X2 (headphones) +0.30, -0.37 -87.2 91.0 0.0081 0.356 -48.4

Android 10 and One UI 2 out of the box

The Galaxy A51 is one of the first Samsung phones to boot Android 10 out of the box, complete with the latest custom One UI 2.0. It’s nice to see that new models are launching with their software already up to date, as opposed to having to wait several months for an OTA.





We’ve already seen the 10/2.0 combo on several flagship Galaxies, where it arrived as an update. On top of that, the second version of One UI isn’t all that different from the original, save for the new take on gesture navigation. Even so, the A51‘s build comes with a small surprise – you get Edge screen.

Previously reserved for the flagships where they would go together with the curved edge displays, the Edge screen set of features have made their way to the mostly flat-screened Galaxy A51. Edge panels is a well-known, long-standing feature that gives you quick access to apps, actions, tools, etc. with a single swipe from the side. You can choose which side the handle is located on, as well as adjust its position along the edge of the phone. In the Edge screen sub-menu, you will also find Edge lighting – it’s a feature that can light up different types of peripheral glow for notifications, and as you’ve probably guessed, there are tons of options and styles to choose from.

Gesture navigation is also available, and you get to pick between the One UI 2 set of actions or go back to the One UI 1 way of doing things. The former is similar to the current native Android 10 approach with a swipe-in from the sides for ‘Back’ and swipe-up from the bottom for Home or task switcher. The old way is by swiping up from three separate areas on the bottom that do what the on-screen buttons before them used to do. If you can’t be bothered with gesturess, the conventional onscreen nav bar remains an option too.

Other cool recent developments have made their way to the A51, including Dark mode. It skins UI elements in black and shades of dark gray and also invokes the dark modes of supported apps, which include the in-house ones as well as the Google suite (not Maps, though, not yet).

Biometrics on the Galaxy A51 include an optical fingerprint reader and basic camera-only face detection. The fingerprint reader experience is trouble-free, with the usual multi-step setup feeling a bit tedious but rewarding when it comes to accuracy afterwards.





It’s not the fastest of sensors and feels more like Samsung‘s ultra-sonic units in the flagships as opposed to a good, nearly-instant optical one, and the laggy animation doesn’t help with perceived speed, but it’s mostly a usable reader that doesn’t get in the way.

Other than that, the Galaxy A51‘s UI is One UI as we’ve come to enjoy. The shift of actionable UI elements towards the bottom for easier reach has been widely praised, and we’re also digging the iconography.

Synthetic benchmarks

The Galaxy A51 is powered by the in-house Exynos 9611 chipset – a minor refresh on the 9610 found in last year’s model, and a refresh that only addresses high-res camera support. In fact, we did see an uptick in performance on the M30s, which uses the 9611 too, so there’s probably more than meets the eye in the specsheets.

Anyway, this particular Exynos is built on a 10nm process and packs an octa-core CPU in a classic 2×4 configuration – 4×2.3GHz Cortex-A73 & 4×1.7GHz Cortex-A53. The GPU is Mali-G72 MP3. Three RAM/storage versions are in existence – 4/64GB, 4/128GB, and 6/128GB, with our review unit being the mid spec.





In our benchmarking session, the Galaxy A51 proved it’s not up to the standard set by competitors in the price range. The Snapdragon 730 present in the Realme X2 and the Xiaomi Mi 9T is significantly more powerful in all applications, be it CPU- or GPU-intense. The Huawei Nova 5T that relies on the once flagship Kirin 980 SoC is in a class of its own, yet fits the budget. The A51 is keeping company to the Nokia 7.2 in terms of CPU performance, but even that ancient Snapdragon 660 in the 7.2 has better graphics than the Galaxy.


NETWORK   Technology GSM / HSPA / LTE


LAUNCH       Announced 2019, December 12
Status Available. Released 2019, December 16


BODY            Dimensions 158.5 x 73.6 x 7.9 mm (6.24 x 2.90 x 0.31 in)
Weight 172 g (6.07 oz)
Build Glass front (Gorilla Glass 3), plastic back, plastic frame
SIM Single SIM (Nano-SIM) or Dual SIM (Nano-SIM, dual stand-by)


DISPLAY        Type Super AMOLED capacitive touchscreen, 16M colors
Size 6.5 inches, 102.0 cm2 (~87.4% screen-to-body ratio)
Resolution 1080 x 2400 pixels, 20:9 ratio (~405 ppi density)
Protection Corning Gorilla Glass 3


PLATFORM   OS Android 10, One UI 2.1
Chipset Exynos 9611 (10nm)
CPU Octa-core (4×2.3 GHz Cortex-A73 & 4×1.7 GHz Cortex-A53)
GPU Mali-G72 MP3


MEMORY        Card slot microSDXC (dedicated slot)
Internal 64GB 4GB RAM, 128GB 4GB RAM, 128GB 6GB RAM, 128GB 8GB RAM
UFS 2.0


MAIN CAMERA             Quad 48 MP, f/2.0, 26mm (wide), 1/2.0″, 0.8µm, PDAF
12 MP, f/2.2, 123˚ (ultrawide)
5 MP, f/2.4, (macro)
5 MP, f/2.2, (depth)
Features LED flash, panorama, HDR
Video 4K@30fps, 1080p@30/120fps; gyro-EIS


SELFIE CAMERA      Single 32 MP, f/2.2, 26mm (wide), 1/2.8″, 0.8µm
Features HDR
Video 1080p@30fps


SOUND                 Loudspeaker Yes
3.5mm jack Yes


COMMS                WLAN Wi-Fi 802.11 a/b/g/n/ac, dual-band, Wi-Fi Direct, hotspot
Bluetooth 5.0, A2DP, LE
Radio FM radio
USB 2.0, Type-C 1.0 reversible connector, USB On-The-Go


FEATURES                 Sensors Fingerprint (under display, optical), accelerometer, gyro, proximity, compass


BATTERY                     Non-removable Li-Po 4000 mAh battery
Charging Fast charging 15W


MISC                   Colors Prism Crush Black, Prism Crush White, Prism Crush Blue, Prism Crush Pink
Models SM-A515F, SM-A515F/DSN, SM-A515F/DS, SM-A515F/DST, SM-A515F/DSM, SM-A515F/N
SAR 0.80 W/kg (head)     0.67 W/kg (body)
SAR EU 0.37 W/kg (head)     1.59 W/kg (body)
Price $ 282.88 / € 277.00 / £ 264.99 / ₹ 26,999


TESTS             Performance AnTuTu: 113051 (v7), 175363 (v8)
GeekBench: 5401 (v4.4), 1294 (v5.1)
GFXBench: 5.6fps (ES 3.1 onscreen)
Display Contrast ratio: Infinite (nominal)
Camera Photo / Video
Loudspeaker -28.6 LUFS (Average)
Audio quality Noise -93.1dB / Crosstalk -87.3dB
Battery life
Endurance rating 86h


Samsung‘s never going to have it easy in the midrange, with great value handsets coming from the likes of Xiaomi and Realme. The brand image is one thing, but can the Galaxy A51 stand up to the competition for the brand-agnostic buyer?





At €300, the Realme X2 is some 10-15% cheaper than the Galaxy A51‘s €340-ish for a matching 128GB storage level, though the Realme will come with twice as much RAM (8GB vs. 4GB). The Realme has a vastly more powerful chipset across the board and delivers longer battery life. The A51‘s ultra-wide and macro cameras are better, while the X2’s main shooter makes a compelling case for itself, and there aren’t bad displays between these two. We’d call the Realme a winner here, if you don’t mind that people around the table may need some explaining where your phone comes from.

Xiaomi’s lineup is particularly tough to navigate, with numerous mid-tier models available, but certainly not all of them everywhere. A Mi 9T is a reasonably global player (known in some markets as Redmi K20), and it retails for about as much as the Galaxy A51 for comparable storage tiers. The Galaxy walks into this underpowered again, with the Xiaomi packing a brawnier chipset and Infinity-O as it may be, the A51‘s display still has a hole in it, unlike the Xiaomi with its retractable selfie cam. The 9T/K20 also has a telephoto camera, to which the Galaxy has no answer. Again, it’s only the brand that can have you going Galaxy instead of Mi.

A Huawei Nova 5T (or its Honor 20 cousin) could be a viable option in the Galaxy A51‘s price bracket if you want some of that Huawei goodness from the pre-trade war times when Huaweis had Google support. The Kirin 980 inside the Nova is a proper beast compared to the Exynos in the Samsung, while battery life is comparable between the two phones, but we’d pick the A51 when it comes to displays.



Realme X2 • Xiaomi Mi 9T • Huawei nova 5T




The Galaxy A51 offers a sensible package of features and performs well in most key areas. It’s one of the lightest handsets in the segment while still having a big display and doesn’t sacrifice battery life in the process. Typically for a Samsung, the A51‘s display leaves little to complain about too. A thorough upgrade in the camera department means good daylight photos from all cameras, with particularly great portraits and a ‘macro’ cam that’s hard to beat. The up to date software at launch, complete with added features which used to be reserved for the flagships until only recently, rounds up a compelling list of pros.





The thing is, though, competitors have all these boxes checked too, and then some. Pretty much every phone for the money will come with a more powerful chipset, and you’ll especially appreciate it if you’re into gaming, but future-proofing is also a valid concern. Samsung‘s not too keen on making its midranger cameras shoot too great in the dark, while others don’t necessarily pull their punches quite as much.

More importantly, key rivals come at a lower price, with few objective trade-offs. With that in mind, we can’t wholeheartedly recommend the Galaxy A51 at the current price. If you absolutely must have a Samsung (which is a sentiment we can understand), this one isn’t bad to spend the brand-related premium on. A carrier subsidy could also sweeten the Galaxy deal, and that you may not be able to get on the Xiaomis and Realmes of the world. But if we are buying at full retail price, our money wouldn’t be on the A51 judging strictly on its merits.


  • Compact and light for the display size and battery capacity, standout design.
  • Dependable battery life, reasonably fast charging.
  • Super AMOLED display that’s plenty bright and good with colors.
  • Superb portraits, better than average closeups, generally good daylight image quality from all cameras.
  • Android 10 out of the box, One UI 2 has plenty going for it.


  • Chipset isn’t as powerful as what the competition has to offer.
  • Camera performance is lacking in low light.
  • No video stabilization in 4K, no 60fps mode in 1080p.