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The PerfectRec phone team Learn more
Updated January 10, 2024·
If you prioritize a larger screen and slightly longer battery life, the Samsung Galaxy S21+ may be a better choice for you. However, the OnePlus 9 offers a higher quality main camera, which could be important if photography is a priority for you. Both phones have similar performance capabilities and support for 5G. Neither has a headphone jack or expandable storage with an SD card, and they both have wireless charging and water resistance. The OnePlus 9 has alert slider functionality, which is not present on the S21+. Overall, if camera quality is more critical for you and you're willing to accept a slightly smaller screen and a bit less battery life, the OnePlus 9 is preferable, despite its higher price. 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
- The OnePlus 9 has no clear advantages over the Samsung Galaxy S21+.
Advantages of the Samsung Galaxy S21+
- Good for taking photos
- Fair for recording videos
- Very good battery life
- Very good display quality
- Good performance
Key differences
Video Quality
5.9
6.6
The Samsung Galaxy S21+ takes only fair videos, while the OnePlus 9 takes poor videos.
The OnePlus 9 has fair video capabilities majorly due to lower scores in software experience, stabilization, and low light performance, accompanied by modest microphone quality. In contrast, the Samsung Galaxy S21+ delivers good video results with better stabilization, dynamic range, and low light performance, alongside superior microphone quality, which collectively enhance the overall video recording experience.
Battery
6.9 Hours
8.0 Hours
The OnePlus 9 has 6.9 hours of battery life. The Samsung Galaxy S21+ has 8 hours of battery life.
Cost
$399
$340
$100
$200
$300
$400
$500
$600
The OnePlus 9 has a price of $399 and the Samsung Galaxy S21+ costs $340.
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Key similarities
Overall Camera Quality
7.0
7.2
The Samsung Galaxy S21+ and OnePlus 9 both have good overall cameras quality.
The OnePlus 9's selfie capabilities are rated as good, but it lags in photos software experience and camera versatility compared to the Samsung Galaxy S21+, which is rated very good in selfie quality and offers a better overall photo software experience.
Photo Quality
6.7
7.0
Although they have very similar scores, PerfectRec considers Samsung Galaxy S21+ to have good photos, while the OnePlus 9 takes only fair photos.
The Samsung Galaxy S21+ takes good photos due to its higher photos software experience and better selfie quality as compared to the OnePlus 9. While the OnePlus 9's photo capabilities are satisfactory, the Galaxy S21+ offers sharper selfies and more vibrant photographs overall.
Screen Size
The OnePlus 9 has a screen size of 6.55 inches and the Samsung Galaxy S21+ is 6.7 inches.
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How the OnePlus 9 and the Samsung Galaxy S21+ compare to other phones
Spec Comparison
 |  | |
| OnePlus 9 | Samsung Galaxy S21+ |
GENERAL | |||
|---|---|---|---|
| Price | |||
$399 | $340 | ||
Brand | |||
Brand | OnePlus | Samsung | |
Operating System | |||
Operating System | Android | Android | |
Release Date | |||
Release Date | March 26, 2021 | January 29, 2021 | |
SCREEN | |||
|---|---|---|---|
Screen Size | |||
Screen Size | 6.55" | 6.7" | |
Resolution | |||
Resolution | 2400 x 1080 | 2400 x 1080 | |
Variable refresh rate | |||
Variable refresh rate | No | No | |
Pixels Per Inch | |||
Pixels Per Inch | 402 | 394 | |
Display Type | |||
Display Type | OLED | OLED | |
INTERNAL | |||
|---|---|---|---|
Processor | |||
Processor | SD888 | SD888 | |
Internal Storage | |||
Internal Storage | 128 GB | 128 GB | |
RAM | |||
RAM | 8 GB | 8 GB | |
CAMERA | |||
|---|---|---|---|
Overall Camera Quality Score | |||
Overall Camera Quality Score | 7/10 | 7.2/10 | |
Photos Score | |||
Photos Score | 6.8/10 | 7/10 | |
Videos Score | |||
Videos Score | 5.9/10 | 6.6/10 | |
Rear Cameras | |||
Rear Cameras | Main, Ultrawide | Main, Ultrawide, Telephoto | |
Main Camera | |||
Main Camera | 48 megapixels | 12 megapixels + OIS | |
BATTERY | |||
|---|---|---|---|
Battery Life | |||
Battery Life | 6.9 Hours | 8 Hours | |
Battery Capacity | |||
Battery Capacity | 4500 mAh | 4800 mAh | |
Wireless Charging | |||
Wireless Charging | Yes | Yes | |
Wireless charging Speed | |||
Wireless charging Speed | 15 W | 15 W | |
Reverse wireless charging | |||
Reverse wireless charging | No | Yes (4.5 watts) | |
PHYSICAL | |||
|---|---|---|---|
Size | |||
Size | 6.29" x 2.92" | 6.36" x 2.98" | |
Weight | |||
Weight | 6.77 oz | 7.05 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 | 5.0 | |
A2DP | |||
A2DP | Yes | Yes | |
WiFi Version | |||
WiFi Version | 6 | 6 | |
NFC | |||
NFC | Yes | Yes | |
US 5G Bands | |||
US 5G Bands | (SA/NSA/Sub6)1, 2, 3, 5, 7, 8, 20, 25, 28, 38, 40, 41, 48, 66, 71, 77, 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 | Astral Black, Arctic Sky, Winter Mist | Phantom Black, Phantom Silver, Phantom Violet, Phantom Pink, Phantom Gold, Phantom Red | |
Stock Android | |||
Stock Android | No | No | |
SD Card | |||
SD Card | No | No | |
Shopping
OnePlus 9
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Dig into reviews and images
TechRadar
David Lumb | April 2021
"If you’re hunting for the best Android camera phone at this price, and one that doesn’t skimp on specs the OnePlus 9 is worth considering. Courtesy of a partnership with Hasselblad, the cameras offer better color correction, and both regular and ultra-wide photos look great. The OnePlus 9’s battery fully charges in under 30 minutes over a cable, and in 45 minutes using wireless charging. If you hate waiting for hours to charge your phone, you'll love the OnePlus 9."
Samsung Galaxy S21+
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Dig into reviews and images
Tom's Guide
Jordan Palmer | May 2022
"All told, Samsung nailed it with the Galaxy S21 Plus. It has most of the strengths of the smaller S21 in a bigger package. It’s got a lot going for it. If you’re coming from an older device, like the Galaxy S10 series, this is a solid upgrade."
Get a great deal on the OnePlus 9 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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Why trust us
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
68
Phones evaluated
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Phones stats compiled
8
Proprietary Phones ratings developed
140,400
Recommendations made
79,560
Consumer hours saved
About the phone team
Joe Golden, Ph.D
CEO and Phones Editor
Joe is an entrepreneur and lifelong electronics enthusiast with a Ph.D in Economics from the University of Michigan.
Jason Lew
Staff Expert & Software Engineer
Jason is a staff expert and software engineer that has been making laptop recommendations for 7 years and moderates one of the largest laptop subreddits.
Chandradeep Chowdhury
Staff Expert & Software Engineer
Chandradeep is a staff expert and software engineer and expert in televisions and monitors. He’s been making monitor recommendations for ten years.
Seth Peoples
Phones Expert
Seth is a US-based product expert focusing on smartphones and he is a moderator of one of the largest smartphone subreddits. His tailored recommendations have helped him earn over 87k comment karma, putting him in the top 1% of Redditors.
Efthimis Kotanidis
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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