Samsung Galaxy A51 vs Xiaomi Redmi Note 9 Pro
A spec-by-spec comparison of the Samsung Galaxy A51 and the Xiaomi Redmi Note 9 Pro, taken from their full specification sheets. Green marks the better value in each measured row.
Head to head
| Samsung Galaxy A51 | Xiaomi Redmi Note 9 Pro |
|---|
| Price | $79 | $180 |
| Our rating | 7/10 | 7/10 |
| Battery | 4,000 mAh | 5,020 mAh |
| Wired charging | 15W | 30W |
| RAM (max) | 8 GB | 8 GB |
| Storage (max) | 256 GB | 128 GB |
| Screen size | 6.5 in | 6.67 in |
| Main camera | 48 MP | 64 MP |
| Weight (lower is lighter) | 172 g | 209 g |
| Released | Dec 2019 | May 2020 |
Summary: Samsung Galaxy A51 is ahead on storage (max), weight (lower is lighter). Xiaomi Redmi Note 9 Pro is ahead on battery, wired charging, screen size, main camera.
★ Which should you buy? Xiaomi Redmi Note 9 Pro is the stronger overall pick on the measured specs. If budget matters more than the extra capability, Samsung Galaxy A51 is the cheaper option.
Researched with AI assistance by infozme.com from manufacturer and retailer sources — see how we research & rate phones.
Display
| Samsung Galaxy A51 | Xiaomi Redmi Note 9 Pro |
|---|
| Type | Super AMOLED, 16M colors | IPS LCD, 450 nits (typ) |
| Size | 6.5 inches, 102.0 cm² (~87.4% screen-to-body ratio) | 6.67 inches, 107.4 cm2 (~84.5% screen-to-body ratio) |
| Resolution | 1080 x 2400 pixels, 20:9 ratio (~405 ppi density) | 1080 x 2400 pixels, 20:9 ratio (~395 ppi density) |
| Protection | Corning Gorilla Glass 3 | Corning Gorilla Glass 5 |
| Features | Infinity-O Display | — |
| Refresh Rate | — | 60Hz |
Platform
| Samsung Galaxy A51 | Xiaomi Redmi Note 9 Pro |
|---|
| OS | Android 10, upgradable to Android 13, One UI 5.1 | Android 10, MIUI 11 (upgradable to Android 12, MIUI 14) |
| Chipset | Exynos 9611 (10 nm) | Qualcomm SM7125 Snapdragon 720G (8 nm) |
| CPU | Octa-core (4x2.3 GHz Cortex-A73 & 4x1.7 GHz Cortex-A53) | Octa-core (2x2.3 GHz Kryo 465 Gold & 6x1.8 GHz Kryo 465 Silver) |
| GPU | Mali-G72 MP3 | Adreno 618 |
Memory
| Samsung Galaxy A51 | Xiaomi Redmi Note 9 Pro |
|---|
| Card slot | microSDXC (dedicated slot) | microSDXC (dedicated slot) |
| Internal | 64GB 4GB RAM, 128GB 4GB RAM, 128GB 6GB RAM, 128GB 8GB RAM, 256GB 8GB RAM | 64GB 6GB RAM, 128GB 6GB RAM, 128GB 8GB RAM |
| Type | — | UFS 2.1 |
Main Camera
| Samsung Galaxy A51 | Xiaomi Redmi Note 9 Pro |
|---|
| 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/2.4, (depth) | 64 MP, f/1.9, 26mm (wide), 1/1.72", 0.8µm, PDAF; 8 MP, f/2.2, 119˚ (ultrawide), 1/4.0", 1.12µm; 5 MP, f/2.4, (macro), AF; 2 MP, f/2.4, (depth) |
| Features | LED flash, panorama, HDR | LED flash, HDR, panorama |
| Video | 4K@30fps, 1080p@30/120fps; gyro-EIS | 4K@30fps, 1080p@30/60/120fps, 720p@960fps, gyro-EIS |
Selfie Camera
| Samsung Galaxy A51 | Xiaomi Redmi Note 9 Pro |
|---|
| Single | 32 MP, f/2.2, 26mm (wide), 1/2.8", 0.8µm | 16 MP, f/2.5, (wide), 1/3.06" 1.0µm |
| Features | HDR | HDR, panorama |
| Video | 4K@30fps, 1080p@30fps | 1080p@30fps |
Battery
| Samsung Galaxy A51 | Xiaomi Redmi Note 9 Pro |
|---|
| Type | Li-Po 4000 mAh, non-removable | Li-Po 5020 mAh, non-removable |
| Charging | 15W wired | 30W wired, 50% in 30 min (advertised) |
Body
| Samsung Galaxy A51 | Xiaomi Redmi Note 9 Pro |
|---|
| Dimensions | 158.5 x 73.6 x 7.9 mm (6.24 x 2.90 x 0.31 in) | 165.8 x 76.7 x 8.8 mm (6.53 x 3.02 x 0.35 in) |
| Weight | 172 g (6.07 oz) | 209 g (7.37 oz) |
| Build | Glass front (Gorilla Glass 3), plastic back, plastic frame | Glass front (Gorilla Glass 5), glass back (Gorilla Glass 5), plastic frame |
| SIM | Single SIM (Nano-SIM) or Dual SIM (Nano-SIM, dual stand-by) | Dual SIM (Nano-SIM, dual stand-by) |
Comms
| Samsung Galaxy A51 | Xiaomi Redmi Note 9 Pro |
|---|
| WLAN | Wi-Fi 802.11 a/b/g/n/ac, dual-band, Wi-Fi Direct | Wi-Fi 802.11 a/b/g/n/ac, dual-band, Wi-Fi Direct |
| Bluetooth | 5.0, A2DP, LE | 5.0, A2DP, LE |
| Positioning | GPS, GLONASS, GALILEO, BDS | GPS, GLONASS, GALILEO, BDS, NavIC |
| NFC | Yes (market/region dependent) | Yes |
| USB | USB Type-C 2.0 | USB Type-C 2.0, OTG |
| Infrared port | — | Yes |
| Radio | — | FM radio |
Launch
| Samsung Galaxy A51 | Xiaomi Redmi Note 9 Pro |
|---|
| Announced | December 12, 2019 | 2020, April 30 |
| Released | December 16, 2019 | — |
| Status | — | Available. Released 2020, May 05 |
Frequently asked questions
Which has the better battery, Samsung Galaxy A51 or Xiaomi Redmi Note 9 Pro?
Xiaomi Redmi Note 9 Pro — 4,000 mAh for the Samsung Galaxy A51 versus 5,020 mAh for the Xiaomi Redmi Note 9 Pro.
Which is lighter, Samsung Galaxy A51 or Xiaomi Redmi Note 9 Pro?
Samsung Galaxy A51 — 172 g for the Samsung Galaxy A51 versus 209 g for the Xiaomi Redmi Note 9 Pro.
Which is newer, Samsung Galaxy A51 or Xiaomi Redmi Note 9 Pro?
Xiaomi Redmi Note 9 Pro — Dec 2019 for the Samsung Galaxy A51 versus May 2020 for the Xiaomi Redmi Note 9 Pro.
Is the Samsung Galaxy A51 or the Xiaomi Redmi Note 9 Pro rated higher?
We rate the Samsung Galaxy A51 7/10 and the Xiaomi Redmi Note 9 Pro 7/10.
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