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What we think
The PerfectRec phone team Learn more
Updated January 10, 2024·
The OnePlus 9 Pro is less expensive and provides a similar high refresh rate screen as the Samsung Galaxy S21 Ultra, but the S21 Ultra has a slightly larger screen with higher peak brightness, which may translate to better visibility in bright conditions. Both phones offer powerful processors, ample RAM, and quality cameras, with the S21 Ultra boasting a higher megapixel main camera and additional telephoto and periscope lenses for superior zoom capabilities, making it a better choice if photography is a priority. For battery life, the S21 Ultra edges ahead slightly. If budget is the main concern, go with the OnePlus 9 Pro, but for the best camera system and display brightness, the S21 Ultra is worth the extra cost. Both run Android and lack a headphone jack, but offer 5G support and no SD card slot. 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 Ultra
- The Samsung Galaxy S21 Ultra has no clear advantages over the OnePlus 9 Pro.
Key differences
Overall Camera Quality
7.2
7.8
The Samsung Galaxy S21 Ultra and OnePlus 9 Pro both have good overall camera quality, though the Samsung Galaxy S21 Ultra has somewhat better overall camera quality.
The OnePlus 9 Pro offers a strong selfie experience with good photo resolution, as well as versatile camera capabilities and satisfactory low light performance. The Samsung Galaxy S21 Ultra, with its HDR10+ photo capability and remarkable 10x optical zoom telephoto lens, ensures high-quality photo and video capture across various scenarios, along with better microphone quality for audio capture.
Photo Quality
7.0
7.8
The Samsung Galaxy S21 Ultra and OnePlus 9 Pro both have good photos, though the Samsung Galaxy S21 Ultra takes somewhat better photos.
The OnePlus 9 Pro offers a good selfie camera, with a well-rounded camera experience including fair dynamic range and good low light performance, but the Samsung Galaxy S21 Ultra boasts a very good selfie camera, excelling in low light conditions and camera versatility due to its higher-resolution main camera and superior zoom capabilities.
Video Quality
6.0
7.1
The Samsung Galaxy S21 Ultra takes good videos, while the OnePlus 9 Pro takes only fair videos.
The OnePlus 9 Pro delivers excellent video performance through superior stabilization and dynamic range, which ensures smooth footage with balanced lighting, while the Samsung Galaxy S21 Ultra stands out with its remarkable low-light video capabilities and high-quality microphone, making it ideal for capturing crisp audio and clear videos in darker environments. Both phones offer high video resolution and frame rates for sharp, fluid recordings, with the Galaxy S21 Ultra further enhancing the video experience with its video software that supports HDR10+, giving it an edge in creating videos with rich colors and contrasts.
Cost
$499
$423
$200
$300
$400
$500
$600
$700
$800
The OnePlus 9 Pro has a price of $499 and the Samsung Galaxy S21 Ultra costs $423.
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Key similarities
Battery
6.9 Hours
6.7 Hours
The OnePlus 9 Pro has 6.9 hours of battery life. The Samsung Galaxy S21 Ultra has 6.7 hours of battery life.
Screen Size
The OnePlus 9 Pro has a screen size of 6.7 inches and the Samsung Galaxy S21 Ultra is 6.8 inches.
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How the OnePlus 9 Pro and the Samsung Galaxy S21 Ultra compare to other phones
Spec Comparison
 |  | |
| OnePlus 9 Pro | Samsung Galaxy S21 Ultra |
GENERAL | |||
|---|---|---|---|
| Price | |||
$499 | $423 | ||
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" | 6.8" | |
Resolution | |||
Resolution | 3216 x 1440 | 3200 x 1440 | |
Variable refresh rate | |||
Variable refresh rate | Yes | Yes | |
Pixels Per Inch | |||
Pixels Per Inch | 525 | 515 | |
Display Type | |||
Display Type | OLED | OLED | |
INTERNAL | |||
|---|---|---|---|
Processor | |||
Processor | SD888 | SD888 | |
Internal Storage | |||
Internal Storage | 128 GB | 128 GB | |
RAM | |||
RAM | 12 GB | 12 GB | |
CAMERA | |||
|---|---|---|---|
Overall Camera Quality Score | |||
Overall Camera Quality Score | 7.2/10 | 7.9/10 | |
Photos Score | |||
Photos Score | 7.1/10 | 7.8/10 | |
Videos Score | |||
Videos Score | 6.1/10 | 7.1/10 | |
Rear Cameras | |||
Rear Cameras | Main, Ultrawide, Telephoto | Main, Ultrawide, Telephoto, Super Telephoto | |
Main Camera | |||
Main Camera | 48 megapixels + OIS | 108 megapixels + OIS | |
BATTERY | |||
|---|---|---|---|
Battery Life | |||
Battery Life | 6.9 Hours | 6.7 Hours | |
Battery Capacity | |||
Battery Capacity | 4500 mAh | 5000 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" | 6.5" x 2.98" | |
Weight | |||
Weight | 6.95 oz | 8.01 oz | |
Back Material | |||
Back Material | Glass | Glass | |
Stereo Speakers | |||
Stereo Speakers | No | No | |
CONNECTIVITY | |||
|---|---|---|---|
Dual SIM | |||
Dual SIM | No | Yes | |
Bluetooth Version | |||
Bluetooth Version | 5.2 | 5.2 | |
A2DP | |||
A2DP | Yes | Yes | |
WiFi Version | |||
WiFi Version | 6 | 6e | |
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 Black, Phantom Silver, Phantom Navy, Phantom Titanium | |
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 Ultra
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Dig into reviews and images
Android Authority
David Imel | January 2023
"The Galaxy S21 Ultra is a killer combo of great design, blazing-fast performance, a wonderful display, long-lasting battery life, and one of the most versatile camera systems you can get in a smartphone today."
Get a great deal on the OnePlus 9 Pro or the Samsung Galaxy S21 Ultra
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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Joe is an entrepreneur and lifelong electronics enthusiast with a Ph.D in Economics from the University of Michigan.
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