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What we think
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Updated January 10, 2024·
If camera quality is a top priority for you, the OnePlus 9 Pro offers a superior camera experience, with higher still photo and video quality than the Samsung Galaxy S21. However, if you're looking to save money, the Galaxy S21 is more budget-friendly. In terms of battery life, both phones are similar, but the OnePlus 9 Pro has a slightly larger screen, which might be better for media consumption, though it could also mean a larger, heavier phone to carry. One difference to note is that the Galaxy S21's back is made of plastic, which might not feel as premium as the OnePlus 9 Pro's glass back. Both phones run on Android, offer high refresh rate displays for smooth scrolling, and have 5G capabilities. If you want a stylus or a headphone jack, neither phone has these features built-in. Give Feedback
this description is based on the product variant with some specs and product variant with some specs. At the time of writing, the variant with some specs cost some dollars and the variant with some specs cost some dollars.
Advantages of the OnePlus 9 Pro
- Best in class display quality
Advantages of the Samsung Galaxy S21
- The Samsung Galaxy S21 has no clear advantages over the OnePlus 9 Pro.
Key differences
Video Quality
6.0
6.6
The Samsung Galaxy S21 and OnePlus 9 Pro both have only fair videos, though the Samsung Galaxy S21 takes somewhat better videos.
The OnePlus 9 Pro offers superior video stabilization, making it a strong choice for capturing smooth footage, while its microphone quality ensures clear audio capture. The Samsung Galaxy S21 excels in video resolution and frame rate, providing sharp videos with smooth motion, and its video dynamic range allows for well-balanced visuals with detail in both bright and dark areas, even though it slightly underperforms in low light compared to the OnePlus.
Screen Size
The OnePlus 9 Pro has a screen size of 6.7 inches and the Samsung Galaxy S21 is 6.2 inches.
Cost
$499
$145
$0
$200
$400
$600
$800
The OnePlus 9 Pro has a price of $499 and the Samsung Galaxy S21 costs $145.
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Key similarities
Overall Camera Quality
7.2
7.2
The Samsung Galaxy S21 and OnePlus 9 Pro both have good overall cameras quality.
The OnePlus 9 Pro boasts impressive selfie quality, backed by its sufficient camera versatility which means it not only takes good front-facing photos but also offers a range of shooting options; however, its low light and dynamic range capabilities are just fair, implying there might be limitations under certain lighting conditions. In contrast, the Samsung Galaxy S21 matches the OnePlus in selfie quality and outperforms it in video recording features with better stabilization and dynamic range, suggesting smoother videos and better performance in varying light—but it does have a smaller default storage space.
Photo Quality
7.0
7.0
The OnePlus 9 Pro and Samsung Galaxy S21 both have good photos.
The OnePlus 9 Pro is appreciated for its overall good selfie quality, benefiting from effective photo processing software and offering multiple camera features that enhance versatility in different lighting conditions. In comparison, the Samsung Galaxy S21 also delivers good selfie photos, with its software experience being highly rated, and it maintains quality across various shooting scenarios, including dynamic range and low light performance.
Battery
6.9 Hours
6.7 Hours
The OnePlus 9 Pro has 6.9 hours of battery life. The Samsung Galaxy S21 has 6.7 hours of battery life.
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How the OnePlus 9 Pro and the Samsung Galaxy S21 compare to other phones
Spec Comparison
 |  | |
| OnePlus 9 Pro | Samsung Galaxy S21 |
GENERAL | |||
|---|---|---|---|
| Price | |||
$499 | $145 | ||
Brand | |||
Brand | OnePlus | Samsung | |
Operating System | |||
Operating System | Android | Android | |
Release Date | |||
Release Date | March 30, 2021 | January 29, 2021 | |
SCREEN | |||
|---|---|---|---|
Screen Size | |||
Screen Size | 6.7" | 6.2" | |
Resolution | |||
Resolution | 3216 x 1440 | 2400 x 1080 | |
Variable refresh rate | |||
Variable refresh rate | Yes | No | |
Pixels Per Inch | |||
Pixels Per Inch | 525 | 421 | |
Display Type | |||
Display Type | OLED | OLED | |
INTERNAL | |||
|---|---|---|---|
Processor | |||
Processor | SD888 | SD888 | |
Internal Storage | |||
Internal Storage | 128 GB | 128 GB | |
RAM | |||
RAM | 12 GB | 8 GB | |
CAMERA | |||
|---|---|---|---|
Overall Camera Quality Score | |||
Overall Camera Quality Score | 7.2/10 | 7.2/10 | |
Photos Score | |||
Photos Score | 7.1/10 | 7/10 | |
Videos Score | |||
Videos Score | 6.1/10 | 6.6/10 | |
Rear Cameras | |||
Rear Cameras | Main, Ultrawide, Telephoto | Main, Ultrawide, Telephoto | |
Main Camera | |||
Main Camera | 48 megapixels + OIS | 12 megapixels + OIS | |
BATTERY | |||
|---|---|---|---|
Battery Life | |||
Battery Life | 6.9 Hours | 6.7 Hours | |
Battery Capacity | |||
Battery Capacity | 4500 mAh | 4000 mAh | |
Wireless Charging | |||
Wireless Charging | Yes | Yes | |
Wireless charging Speed | |||
Wireless charging Speed | 50 W | 15 W | |
Reverse wireless charging | |||
Reverse wireless charging | Yes (4.5 watts) | Yes (4.5 watts) | |
PHYSICAL | |||
|---|---|---|---|
Size | |||
Size | 6.43" x 2.9" | 5.97" x 2.8" | |
Weight | |||
Weight | 6.95 oz | 5.96 oz | |
Back Material | |||
Back Material | Glass | Plastic | |
Stereo Speakers | |||
Stereo Speakers | No | No | |
CONNECTIVITY | |||
|---|---|---|---|
Dual SIM | |||
Dual SIM | No | Yes | |
Bluetooth Version | |||
Bluetooth Version | 5.2 | 5.0 | |
A2DP | |||
A2DP | Yes | Yes | |
WiFi Version | |||
WiFi Version | 6 | 6 | |
NFC | |||
NFC | Yes | Yes | |
US 5G Bands | |||
US 5G Bands | (SA/NSA/Sub6/mmWave)1, 2, 3, 7, 25, 28, 41, 66, 71, 78, 258, 260, 261 (SA/NSA/Sub6)41, 78 | (SA/NSA/Sub6/mmWave)2, 5, 25, 41, 66, 71, 260, 261 (SA/NSA/Sub6)1, 3, 5, 7, 8, 20, 28, 38, 40, 41, 66, 77, 78 | |
OTHER FEATURES | |||
|---|---|---|---|
Biometric unlock | |||
Biometric unlock | Face unlock, Fingerprint sensor: Under Display | Face unlock, Fingerprint sensor: Under Display | |
Unlockable Bootloader | |||
Unlockable Bootloader | Yes | No | |
Color | |||
Color | Stellar Black, Forest Green, Morning Mist | Phantom Gray, Phantom White, Phantom Violet, Phantom Pink | |
Stock Android | |||
Stock Android | No | No | |
SD Card | |||
SD Card | No | No | |
Shopping
OnePlus 9 Pro
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Dig into reviews and images
TechRadar
James Peckham | April 2021
"The OnePlus 9 Pro offers phenomenal performance, a vastly superior camera to the brand’s previous smartphones, and a variety of top-end features that make this a serious contender for anyone who’s in the market for a premium Android handset.The 6.7-inch 120Hz QHD display is among the best we’ve seen on a smartphone, with plenty of detail, strong brightness, and a variety of other tweaks. If you like to watch a lot of video on your phone in particular, this is a great option."
Samsung Galaxy S21
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Android Central
Huseman Joe | February 2022
"The Galaxy S21 delivers the flagship Samsung experience in a phone that's much more pocketable (and affordable) than the top-end S21 Ultra.The triple-camera system is incredibly capable, Samsung's One UI 3.1 software is chock-full of features and settings to mess with, and I've not once missed having expandable storage."
Get a great deal on the OnePlus 9 Pro or the Samsung Galaxy S21
About OnePlus
OnePlus, established in 2013, is a smartphone brand that first became known for providing flagship-like devices, at a fraction of the cost compared to more expensive Android competitors. OnePlus focuses on creating smartphones with powerful hardware at reasonable prices. They also bring hardware features normally not seen in other Android phones sold in the US, such as their ultra-fast “Warp Charge” and the beloved “Alert Slider”.
About Samsung
Samsung is one of the most recognizable names in the smartphone industry, standing as the undisputed best-selling brand of Android smartphones in the United States for many years now. Samsung is known for offering a variety of smartphones in all available price points, as well as for implementing cutting-edge technology and innovative features in their flagship devices, ones that often shape the market going forward. The company offers its own unique spin on Android, called One UI, which focuses on offering a multitude of features and is heavily customizable, according to user preference.
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This information was produced and vetted by the PerfectRec phones team. We are a product research and recommendation organization that meticulously reviews and evaluates the latest phone information and makes it digestible for you.
By the numbers
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About the phone team
Joe Golden, Ph.D
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Joe is an entrepreneur and lifelong electronics enthusiast with a Ph.D in Economics from the University of Michigan.
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Chandradeep is a staff expert and software engineer and expert in televisions and monitors. He’s been making monitor recommendations for ten years.
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Phones Expert
Efthimis is a Greece-based product expert focusing on smartphones. He has been recommending phones for 4 years and his recommendations on Reddit have earned him over 35k karma.
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