Choice between Xiaomi Redmi Note 9 Pro and Samsung Galaxy A51 — It's a classic dilemma for mid-range smartphone buyers, because both models launched in 2020 are still heavily marketed in the secondary market and in some regions, even new ones. Chinese “flagship killer” with a powerful processor or Korean smartphone with a brand design and Samsung ecosystem?
At first glance, the differences seem minor: both devices are equipped with a AMOLED-screens, quadruple cameras and 4,000-capacity batteries+ But the devil is in the details, and in this article, we're going to look at 10 key parameters, from performance to software, and give you a clear guide to who will fit each model. And you will learn why the Redmi Note 9 Pro loses in long-term support, but wins in charging speed.
Spoiler: If you want a smartphone for gaming and multitasking, the choice is obvious. If the priority is the quality of photos and videos, it's not that clear. Let's get it straight.
Design and Ergonomics: Plastic vs Glass
Externally, Samsung Galaxy A51 It looks more premium thanks to its gradient glass back, but the same solution makes it more slippery and fragile — without a case, the smartphone will easily slip out of your hand. Redmi Note 9 Pro, on the contrary, is made of matte plastic with a texture under glass, which is more practical in everyday use.
The dimensions of the model are almost identical:
- A51: 158.5 × 73.6 × 7.9 mm, 172 s
- Redmi Note 9 Pro: 165.8 × 76.7 × 8.8 mm, 209 s
The difference in weight is palpable — Xiaomi is 37 grams heavier, which can be critical for users with small hands, but it has a 3.5 mm port for headphones (Samsung does not have one), as well as an infrared port for controlling equipment.
Both smartphones have a fingerprint scanner under the screen, but Samsung has a faster and more accurate fingerprint scanner, but the memory card connector is implemented differently:
- A51: hybrid slot (or 2) SIM, 1 SIM + microSD)
- Redmi Note 9 Pro: a separate slot for microSD + 2 SIM
⚠️ Note: If you are planning to use two SIM-Maps and memory card at the same time, Samsung Galaxy A51 It will not work, you will have to choose between the second SIM memory-expansion.
Screen: AMOLED vs IPS high-frequency
Here wins the Samsung Galaxy A51 - Unconditionally. 6.5-superinch AMOLED permittingly 2400×1080** provide:
Deep black (pixels are simply turned off)
Wide color gamut (105% sRGB)
- Support HDR10+ video-watch
Redmi Note 9 Pro is equipped 6.67-inch IPS-resolution-screen 2400×1080 and frequency of renewal 60 Hz (in some regions sold version with the 120 Hz, but officially in Russia it was not.The main advantages of the screen Xiaomi:
Higher brightness (up to 450 nits vs 430 nits from Samsung)
- Protection of Gorilla Glass 5 (Y) A51** — Gorilla Glass 3)
For gamers and fans of smooth animation, the Redmi Note 9 Pro in a 120Hz version would be the perfect choice. But as standard for the comfort of reading and watching videos, Samsung** wins.
Performance: Snapdragon 720G vs Exynos 9611
This is a key section for those planning to play mobile games or use resource-intensive apps. Xiaomi Redmi Note 9 Pro is equipped with Qualcomm Snapdragon 720G — It's a chipset that's still considered one of the best in the middle segment:
- 8 nuclei (2 × Cortex-A76 @2.3 GHz + 6 × Cortex-A55 @1.8 GHz)
Adreno 618 graphics (supports Vulkan 1.1)
- 5G-ready architecture, although the smartphone itself does not support 5G)
Samsung Galaxy A51 It runs on the Exynos 9611, a processor that is inferior to Snapdragon. 720G** across the fronts:
- 4 nucleus Cortex-A73 @2.3 GHz + 4 nucleus Cortex-A53 @1.7 GHz
- Graphics Mali-G72 MP3 (weakly 30-40% test-test)
Higher heating at long loads
Benchmark results (averages):
| Test | Redmi Note 9 Pro (720G) | Galaxy A51 (Exynos 9611) |
|----------------|------------------------|--------------------------|
| AnTuTu 9 | 275 000 | 180 000 |
| Geekbench 5 | 1,800 (single-core)| 1 300 |
| 3DMark Wild Life| 1 500 | 800 |
In practice, this means:
- V PUBG Mobile on Redmi Note 9 Pro can be played on the settings HDR + Ultra with stable 60 FPS, then A51 You will need to reduce the detail to Smooth.
Multitasking: Xiaomi has up to 12 apps in memory without rebooting, Samsung has a maximum of 8.
⚠️ Note: If you plan to use a smartphone for longer than 2 years, keep in mind that the Exynos 9611 is already morally outdated and does not pull modern games at maximum settings. 720G** It'll be relevant for a couple of years.
💡
For gamers and performance-enhancing users, the Xiaomi Redmi Note 9 Pro is the clear leader, and the difference in speed is noticeable even in everyday tasks.
Cameras: quadruple vs quadruple, but with nuances
Both models have four rear cameras, but their capabilities are very different.
| Parameter | Redmi Note 9 Pro | Galaxy A51 |
|------------------------|-------------------------------|-------------------------------|
| Main camera. | 64 MPP, f/1.9, 1/1.72" | 48 MPP, f/2.0, 1/2.0" |
| Ultrashire | 8 MPP, f/2.2, 119° | 12 MPP, f/2.2, 123° |
| Macro | 5 MPP, f/2.4 | 5 MPP, f/2.4 |
| Depth. | 2 MPP, f/2.4 | 5 MPP, f/2.2 |
| Frontal | 16 MPP, f/2.5 | 32 MPP, f/2.2 |
| Video | 4K@30fps, EIS | 4K@30fps, stabilised|
On Redmi Note paper 9 Pro wins with larger main camera sensor (1/1.72" vs 1/2.0"), It's a great way to get more detail in good light, but Samsung's software processing is traditionally stronger:
- Colors in the photo with A51** more saturated and natural.
Portrait mode works more accurately thanks to a separate 5-MP depth sensor.
- Samsung's nighttime shooting** makes less noise, but loses in detail.
Examples of real photos (conditionally):
Daylight, good lighting: Redmi Note 9 Pro** gives sharper photos, but with a cooler tint.
- Evening, low lighting: Galaxy A51** It can handle noise better, but loses detail in the shadows.
Selfie: Samsung’s 32MP front-end is objectively better, especially for social media.
In the video, both smartphones are filmed in 4K@30fps, Xiaomi has electronic stabilization (EIS)**, It's critical for dynamic filming.
How to turn on the night mode on Xiaomi Redmi Note 9 Pro?
Battery and charging: who lives longer?
Both smartphones are equipped with batteries with a capacity of 4000-5000 mAh, but the approach to energy efficiency and charging they have different.
| Parameter | Redmi Note 9 Pro | Galaxy A51 |
|------------------------|-----------------------|-----------------------|
| Capacity | 5020 mAh | 4,000 mAh |
| Fast charging. | 30 W (includes)| 15 watts (block purchased separately) |
| Charging time 0-100%| 65 minutes. | 120 minutes. |
| Autonomy | Up to 2 days (average usage) | Up to 1.5 days |
Xiaomi** is definitely winning in all respects:
- Big battery (+1020 mAh provides 30-40% more operating time.
A 30-watt adapter in the kit charges the smartphone twice as fast.
- Optimization MIUI It is better at handling the background than One. UI Samsung.
Real tests of autonomy (medium scenario: social networks, instant messengers, 1 hour of video per day):
Redmi Note 9 Pro: 1 day 18 hours**
- Galaxy A51: 1 day 6 hours**
⚠️ Note: If you travel frequently and don’t have access to an outlet, Samsung Galaxy A51 It can be too voracious. When used actively (navigator). + music + social networking site) it will last a maximum of 10-12 hours.
💡
To extend the life of the Galaxy battery A51, Turn off Adaptive Brightness in the settings and set a charge limit to 85% via Device Care → Battery → Additionally.
Software: MIUI vs One UI
At the time of release, both models were running Android 10, but further support for them developed differently:
- Redmi Note 9 Pro: Updated to Android 12 (MIUI 14)** and no longer updated.
- Galaxy A51: Supported up to Android 13 (One) UI 5.1) with the possibility of an unofficial upgrade to Android 14**.
Shell comparison:
| Criteria | MIUI 14 (Xiaomi) | One UI 5.1 (Samsung) |
|------------------------|--------------------------------|--------------------------------|
| Design | Bright, lots of animations. | Minimalistic, closer to Android stock |
| Functions | More customization (themes, gestures) | Best integration with the Samsung ecosystem (Watch, Buds, TV) |
| Advertising | Present in system applications | No advertising. |
| Bloatward | Many pre-installed Chinese apps | Less garbage, but there are duplicate Samsung services** |
Key differences for the user:
- MIUI offers more customizations (for example, you can completely change the appearance of the system through themes), but suffers from advertising in the settings menu.
- One UI It's more stable and optimized, but it's less flexible, but it has chips like DeX and Link to Windows for PC integration.
If you want long-term support, Galaxy A51 The Redmi Note 9 Pro will not receive new versions of Android, which can be a security problem.
Turn off the adverts in MIUI|Remove unnecessary applications (Cleaner, Mi Video)|Set up control gestures|Update all apps through Google Play-->
Additional chips: what they can and what they can not
Each smartphone has unique features that can be decisive when choosing.
Xiaomi Redmi Note 9 Pro
✅ Infrared port - control equipment (air conditioners, TVs)
✅ Stereo speakers (Samsung** mono)
✅ Quick charging of 30W complete
✅ Game Turbo Mode for Optimizing Games
Samsung Galaxy A51
✅ Samsung Pay with support MST (It works without NFC)
✅ DeX – Connecting to a monitor in desktop mode
✅ Better assembly (glass) + metal-frame)
✅ Best Ecosystem (Compatible with Watches, Headphones, Samsung TVs**)
If you are using other Samsung devices (such as the Galaxy Watch or Buds), A51 It's a logical choice because of the seamless synchronization, and for those who appreciate multimedia (sound, games), the Redmi Note 9 Pro is a better fit**.
Price and relevance in 2026
In the secondary market, the prices for models vary greatly depending on the state:
- Xiaomi Redmi Note 9 Pro (b/y good condition): 12 000-15,000 ₽**
- Samsung Galaxy A51 (b/y, good condition: 14,000–18,000 ₽**
New devices are no longer sold in official stores, but sometimes unpacked copies are found at a price of 18,000-22,000. ₽.
Should I buy these models in 2026?
- Yes, if:
You need a reliable smartphone for calls, social networks and photos without claims to flagship chips.
You are ready to put up with outdated firmware (especially Xiaomi**).
- Budget capped at 15,000 ₽ below.
- Not if:
- You need long-term support (better Redmi Note 12 Pro or Galaxy) A54).
You play modern games (e.g. Genshin Impact or Call of Duty Mobile at maximum settings).
- Important. 5G-communication (no model supports it).
💡
In 2026, Xiaomi Redmi Note 9 Pro and Samsung Galaxy A51 It can only be recommended as a budget option for undemanding users. For long-term use, it is better to consider newer models.