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Updated January 12, 2024·
If camera quality is important to you, the Asus Zenfone 9 has a superior primary camera but lacks the Samsung Galaxy S21's telephoto lens for zoomed shots. The Zenfone 9 also offers a slightly smaller but higher brightness screen which could be better for outdoor viewing. In terms of battery, the Zenfone 9 has a slightly larger battery, potentially offering longer battery life. However, if you prefer a slightly larger screen, the Galaxy S21 has a 6.2-inch display over the 5.9-inch of the Zenfone 9. Both run Android but the Galaxy S21 comes with features like Wireless DeX for desktop-like experience and an under display fingerprint sensor, whereas the Zenfone 9 includes a traditional side fingerprint sensor and a 3.5mm headphone jack. Considering the higher expense of the Zenfone 9, if budget is a decisive factor, the Galaxy S21 might provide a more cost-effective balance of features. 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 Asus Zenfone 9
- Good battery life
Advantages of the Samsung Galaxy S21
- Good for taking photos
- Fair for recording videos
- Very good display quality
- Good performance
Key differences
Overall Camera Quality
6.2
7.2
The Samsung Galaxy S21 has good overall camera quality, while the Asus Zenfone 9 has only fair overall camera quality.
The Samsung Galaxy S21's camera system, especially for selfies, is superior to that of the Asus Zenfone 9, as the former has a higher-quality selfie camera, which is very important. Additionally, the Galaxy S21 also stands out in terms of photo software experience, photo dynamic range, photo low light performance, and camera versatility, which are all important factors to consider for overall camera performance.
Photo Quality
6.0
7.0
The Samsung Galaxy S21 takes good photos, while the Asus Zenfone 9 takes only fair photos.
The Asus Zenfone 9 takes poorer selfies because it has a lower self-portrait quality than the Samsung Galaxy S21, indicating less capable front camera performance. Additionally, the overall photo experience, including software, dynamic range, and low light performance, is rated higher for the Galaxy S21, contributing to its better camera quality.
Battery
7.8 Hours
6.7 Hours
The Asus Zenfone 9 has 7.8 hours of battery life. The Samsung Galaxy S21 has 6.7 hours of battery life.
Screen Size
The Asus Zenfone 9 has a screen size of 5.9 inches and the Samsung Galaxy S21 is 6.2 inches.
Cost
$700
$145
$0
$200
$400
$600
$800
$1,000
$1,200
The Asus Zenfone 9 has a price of $700 and the Samsung Galaxy S21 costs $145.
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Key similarities
Video Quality
6.4
6.6
The Samsung Galaxy S21 and Asus Zenfone 9 both have only fair videos.
The Samsung Galaxy S21 outperforms the Asus Zenfone 9 in video recording due to better software experience, stabilization, and dynamic range, which all contribute to a higher-quality video output. Additionally, the Galaxy S21 exhibits superior performance under low light conditions and offers better microphone quality, ensuring clearer audio to complement its video capabilities.
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How the Asus Zenfone 9 and the Samsung Galaxy S21 compare to other phones
Spec Comparison
 |  | |
| Asus Zenfone 9 | Samsung Galaxy S21 |
GENERAL | |||
|---|---|---|---|
| Price | |||
$700 | $145 | ||
Brand | |||
Brand | Asus | Samsung | |
Operating System | |||
Operating System | Android | Android | |
Release Date | |||
Release Date | September 15, 2022 | January 29, 2021 | |
SCREEN | |||
|---|---|---|---|
Screen Size | |||
Screen Size | 5.9" | 6.2" | |
Resolution | |||
Resolution | 2400 x 1080 | 2400 x 1080 | |
Variable refresh rate | |||
Variable refresh rate | No | No | |
Pixels Per Inch | |||
Pixels Per Inch | 445 | 421 | |
Display Type | |||
Display Type | OLED | OLED | |
INTERNAL | |||
|---|---|---|---|
Processor | |||
Processor | SD8+G1 | SD888 | |
Internal Storage | |||
Internal Storage | 128 GB | 128 GB | |
RAM | |||
RAM | 6 GB | 8 GB | |
CAMERA | |||
|---|---|---|---|
Overall Camera Quality Score | |||
Overall Camera Quality Score | 6.3/10 | 7.2/10 | |
Photos Score | |||
Photos Score | 6/10 | 7/10 | |
Videos Score | |||
Videos Score | 6.5/10 | 6.6/10 | |
Rear Cameras | |||
Rear Cameras | Main, Ultrawide | Main, Ultrawide, Telephoto | |
Main Camera | |||
Main Camera | 50 megapixels + OIS | 12 megapixels + OIS | |
BATTERY | |||
|---|---|---|---|
Battery Life | |||
Battery Life | 7.8 Hours | 6.7 Hours | |
Battery Capacity | |||
Battery Capacity | 4300 mAh | 4000 mAh | |
Wireless Charging | |||
Wireless Charging | No | Yes | |
Wireless charging Speed | |||
Wireless charging Speed | 0 W | 15 W | |
Reverse wireless charging | |||
Reverse wireless charging | No | Yes (4.5 watts) | |
PHYSICAL | |||
|---|---|---|---|
Size | |||
Size | 5.77" x 2.68" | 5.97" x 2.8" | |
Weight | |||
Weight | 5.96 oz | 5.96 oz | |
Back Material | |||
Back Material | Plastic | Plastic | |
Stereo Speakers | |||
Stereo Speakers | No | No | |
CONNECTIVITY | |||
|---|---|---|---|
Dual SIM | |||
Dual SIM | Yes | Yes | |
Bluetooth Version | |||
Bluetooth Version | 5.2 | 5.0 | |
A2DP | |||
A2DP | Yes | Yes | |
WiFi Version | |||
WiFi Version | 6e | 6 | |
NFC | |||
NFC | Yes | Yes | |
US 5G Bands | |||
US 5G Bands | (SA/NSA/Sub6)1, 2, 3, 5, 7, 8, 12, 20, 25, 28, 29, 30, 38, 40, 41, 48, 66, 71, 77, 78, 89 | (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 | Fingerprint sensor: Side | Face unlock, Fingerprint sensor: Under Display | |
Unlockable Bootloader | |||
Unlockable Bootloader | No | No | |
Color | |||
Color | Sunset Red, Starry Blue | Phantom Gray, Phantom White, Phantom Violet, Phantom Pink | |
Stock Android | |||
Stock Android | Yes | No | |
SD Card | |||
SD Card | No | No | |
Shopping
Asus Zenfone 9
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Dig into reviews and images
Android Authority
Robert Triggs | March 2023
"The Asus Zenfone 9 is a compact device that still packs more than enough power under the hood. It's compact size, Bluetooth and audio features (including a headphone jack!), and hardware gestures combine to offer a package that does enough differently to warrant your attention."
Samsung Galaxy S21
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Dig into reviews and images
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 Asus Zenfone 9 or the Samsung Galaxy S21
About ASUS
Asus is a well-known player in the mobile world, and in the past few years it has been known for covering specific niches in the smartphone market. Their Zenfone line of devices appeal to small phone enthusiasts, by providing very well-rounded and capable phones at a package that is not too large to operate with one hand – something hard to find in modern Android smartphones. Conversely, their ROG line of devices cater to mobile gamers, by providing a slew of hardware and software features, specifically tailored to enhance the mobile gaming experience. Additionally, Asus is one of the only manufacturers left that continues to include headphone jacks in their lineup of phones, a feature that has become exceedingly rare in today's market.
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.
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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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