OnePlus 9 Pro vs Samsung Galaxy S21 Ultra 2
Luke Pollack / Android Authority

OnePlus continues to drive into true flagship territory with the OnePlus 9 series, and the OnePlus 9 Pro is its most expensive smartphone yet. The new OnePlus phones are primed to take on the best of 2021, which includes Samsung’s latest and greatest smartphones, the Galaxy S21 series. How do the two compare? We take a quick look at the OnePlus 9 vs Samsung Galaxy S21!

Our verdict: OnePlus 9 Pro review | OnePlus 9 review


OnePlus 9 vs Samsung Galaxy S21


Specs

OnePlus 9OnePlus 9 ProSamsung Galaxy S21Samsung Galaxy S21 PlusSamsung Galaxy S21 Ultra
Display
OnePlus 9:
6.55-inch flat AMOLED
20:9 aspect ratio
2,400 x 1,080 at 402ppi
120Hz refresh rate (static)
OnePlus 9 Pro:
6.7-inch curved LTPO AMOLED
20.1:9 aspect ratio
3,216 x 1,440 at 525ppi
120Hz refresh rate (adaptive)
Samsung Galaxy S21:
6.2-inch Dynamic AMOLED
Flat FHD+
2,400 x 1,080 at 421ppi
Adaptive 120Hz refresh rate
Samsung Galaxy S21 Plus:
6.7-inch Dynamic AMOLED
Flat FHD+
2,400 x 1,080 at 394ppi
Adaptive 120Hz refresh rate
Samsung Galaxy S21 Ultra:
6.8-inch Dynamic AMOLED
Curved WQHD+
3,200 x 1,440 at 515ppi
Adaptive 120Hz refresh rate
Processor
OnePlus 9:
Qualcomm Snapdragon 888
OnePlus 9 Pro:
Qualcomm Snapdragon 888
Samsung Galaxy S21:
Qualcomm Snapdragon 888 or Samsung Exynos 2100
Samsung Galaxy S21 Plus:
Qualcomm Snapdragon 888 or Samsung Exynos 2100
Samsung Galaxy S21 Ultra:
Qualcomm Snapdragon 888 or Samsung Exynos 2100
RAM
OnePlus 9:
8 or 12GB
OnePlus 9 Pro:
8 or 12GB
Samsung Galaxy S21:
8GB
Samsung Galaxy S21 Plus:
8GB
Samsung Galaxy S21 Ultra:
12 or 16GB
Storage
OnePlus 9:
128 or 256GB
No external storage
OnePlus 9 Pro:
128 or 256GB
No external storage
Samsung Galaxy S21:
128 or 256GB
No external storage
Samsung Galaxy S21 Plus:
128 or 256GB
No external storage
Samsung Galaxy S21 Ultra:
128, 256, or 512GB
No external storage
Power
OnePlus 9:
4,500mAh battery
Warp Charge 65T
65W charger in box
15W Qi-compatible wireless charging
(Wireless only in NA/Europe)
OnePlus 9 Pro:
4,500mAh battery
Warp Charge 65T
65W charger in box
Warp Charge 50 Wireless
10V/6.5A, 20V/3.25A
Output: 50W (with prop. charging stand)
Samsung Galaxy S21:
4,000mAh battery
Fast wired and wireless charging
Samsung Galaxy S21 Plus:
4,800mAh battery
Fast wired and wireless charging
Samsung Galaxy S21 Ultra:
5,000mAh battery
Fast wired and wireless charging
Connectivity
OnePlus 9:
5G support
Wi-Fi 6 support
NFC support
Bluetooth 5.2
OnePlus 9 Pro:
5G support
Wi-Fi 6 support
2x2 MIMO
Wi-Fi 802.11 a/b/g/n/ac/ax
NFC support
Bluetooth 5.2
Samsung Galaxy S21:
5G support
Wi-Fi 6E support
NFC support
Bluetooth 5.0
Samsung Galaxy S21 Plus:
5G support
Wi-Fi 6E support
NFC support
Bluetooth 5.0
Samsung Galaxy S21 Ultra:
5G support
Wi-Fi 6E support
NFC support
Bluetooth 5.0
Cameras
OnePlus 9:
Rear:
1) 48MP main (Sony IMX689)
1/1.43-inch sensor
1.12μm/46MP or 2.24μm/12MP
ƒ/1.8, EIS
2) 50MP ultra-wide (Sony IMX766)
1/1.56-inch sensor
ƒ/2.2
3) 2MP monochrome
Front:
- 16MP single (Sony IMX471)
1.0μm with EIS
ƒ/2.4, fixed focus
OnePlus 9 Pro:
Rear:
1) 48MP main (Sony IMX789)
1/1.43-inch sensor
1.12μm/46MP or 2.24μm/12MP
ƒ/1.8, EIS, OIS
2) 50MP ultra-wide (Sony IMX766)
1/1.56-inch sensor
ƒ/2.2
3) 8MP telephoto
1.0μm, ƒ/2.4
4) 2MP monochrome
Front:
- 16MP single (Sony IMX471)
1.0μm with EIS
ƒ/2.4, fixed focus
Samsung Galaxy S21:
Rear:
- Wide-angle: 12MP, ƒ/1.8, 1.8µm with OIS and dual-pixel AF
- Telephoto: 64MP, ƒ/2.0, 0.8µm with OIS and phase-detection AF
- Ultra-wide: 12MP, ƒ/2.2, 1.4µm with 120-degree FoV
3x hybrid optical/digital zoom
30x "Space Zoom"
Front:
- 10MP, ƒ/2.2, 1.22µm, with dual-pixel AF
Samsung Galaxy S21 Plus:
Rear:
- Wide-angle: 12MP, ƒ/1.8, 1.8µm with OIS and dual-pixel AF
- Telephoto: 64MP, ƒ/2.0, 0.8µm with OIS and phase-detection AF
- Ultra-wide: 12MP, ƒ/2.2, 1.4µm with 120-degree FoV
3x hybrid optical/digital zoom
30x "Space Zoom"
Front:
- 10MP, ƒ/2.2, 1.22µm, with dual-pixel AF
Samsung Galaxy S21 Ultra:
Rear:
- Wide-angle: 108MP, ƒ/1.8, 0.8µm with OIS and phase-detection AF
- Telephoto: 10MP, ƒ/2.4, 1.22µm with OIS, dual-pixel AF, and 3x optical zoom
- Telephoto: 10MP, ƒ/4.9, 1.22µm with OIS, dual-pixel AF, and 10x optical zoom
- Ultra-wide: 12MP, ƒ/2.2, 1.4µm with dual-pixel AF and a 120-degree FoV
- Laser AF sensor
10x optical zoom
100x "Space Zoom"
Front:
- 40MP, ƒ/2.2, 0.7µm, with phase-detection AF
Software
OnePlus 9:
Android 11
Oxygen OS 11
OnePlus 9 Pro:
Android 11
Oxygen OS 11
Samsung Galaxy S21:
Android 11
One UI 3.1
Samsung Galaxy S21 Plus:
Android 11
One UI 3.1
Samsung Galaxy S21 Ultra:
Android 11
One UI 3.1
Dimensions and weight
OnePlus 9:
NA/Europe:
160 x 74.2 x 8.7mm
192g
India/China:
160 x 73.9 x 8.1mm
183g
OnePlus 9 Pro:
Global:
163.2 x 73.6 x 8.7mm
197g
Samsung Galaxy S21:
71.2 x 151.7 x 7.9mm
171g
Samsung Galaxy S21 Plus:
75.6 x 161.5 x 7.8mm
202g
Samsung Galaxy S21 Ultra:
75.6 x 165.1 x 8.9mm
229g
Colors
OnePlus 9:
Winter Mist, Arctic Sky, Astral
Black
OnePlus 9 Pro:
Morning Mist, Forest Green, Stellar
Black
Samsung Galaxy S21:
128GB in Phantom Violet, Phantom Gray, Phantom Pink, and Phantom White
256GB only in Phantom Gray
Future colors: Phantom Gold and Phantom Red
Samsung Galaxy S21 Plus:
1128GB in Phantom Violet, Phantom Silver, and Phantom Black
256GB only in Phantom Black
Future colors: Phantom Gold and Phantom Red
Samsung Galaxy S21 Ultra:
128 GB in Phantom Silver and Phantom Black
256 and 512GB in Phantom Black
Future colors: Phantom Titanium, Phantom Navy, and Phantom Brown

Design

OnePlus 9 Pro left rear laying down
Eric Zeman / Android Authority

OnePlus has refined the design language it introduced with the OnePlus 8 series, and the OnePlus 9 Pro looks the part of a top-of-the-line flagship. Curved glass panels seamlessly blend into a thin metal frame, and the beautiful new colorways (Morning Mist is a winner!) make the phone stand out.

The OnePlus 9 is a less premium version of the 9 Pro in almost every way, including the design and build quality. It’s a good-looking phone though, with a design that will feel familiar to OnePlus fans. Glass panels still sandwich a metal frame, but you get a flat display with the regular OnePlus 9, which some may prefer. Both phones retain OnePlus staples like the handy alert slider and stereo speakers.

The OnePlus 9 series refines the design language introduced with the OnePlus 8 family. The Galaxy S21 trio comes with a cleaner, arguably more polished look.

OnePlus has also seriously upped its camera game with the OnePlus 9 series. That means a noticeable camera module on the back that houses the OnePlus 9 Pro’s four cameras or the OnePlus 9’s three cameras. Both cameras also come with Hasselblad branding to show off OnePlus’ collaboration with the storied camera company for the color tuning, in case you needed a reminder about how serious OnePlus is about its cameras this time around. It’s not unpleasant to look at, and OnePlus has tried its best to make it flow as much as one can with a setup that includes two huge sensors. I still prefer a more minimalistic approach, but as the smartphone camera wars continue, I can’t really blame OnePlus for the new design.

Samsung Galaxy S21 Ultra vs Galaxy S21 Plus
Robert Triggs / Android Authority

The Galaxy S21 series comes with a cleaner, more polished look. The “contour cut” camera is far sleeker and more aesthetically pleasing than what we got with its predecessors. There’s still a significant camera bump, especially with the S21 Ultra, but it flows a lot better at first glance.

Our verdict: Galaxy S21 Ultra review | Galaxy S21 Plus review | Galaxy S21 review

The regular Galaxy S21 comes with a “glasstic” build that is less premium but more durable than the all-glass bodies of the Plus and Ultra. A punch-hole to house the front-facing camera is the only blemish on the near bezel-less front. While you do miss out on the OnePlus alert slider, the Galaxy S21 Plus and Galaxy S21 Ultra switch to Gorilla Glass Victus on the front and back, while the OnePlus 9 series adopts the older Gorilla Glass 5 standard.

As for color options, the OnePlus 9 series is available in Winter Mist, Arctic Sky, Astral Black (OnePlus 9), or Morning Mist, Pine Green, Stellar Black (OnePlus 9 Pro). The Galaxy S21 series has a huge number of color options, though some are exclusive to certain models and carriers. Check out the full list in the specs table at the top of this article.


Features

OnePlus 9 Pro in hand display
Eric Zeman / Android Authority

The Qualcomm Snapdragon 888 processor powers the OnePlus 9 and OnePlus 9 Pro, with 8 or 12GB of RAM, 128GB or 256GB of storage, and the same 4,500mAh battery with OnePlus’ 65T warp charging. This new 65W charger will fully charge the battery in just under half an hour. If performance is your only criteria, you can save a decent chunk of money with the regular OnePlus 9.

If fast charging is important to you, then the OnePlus 9 or 9 Pro is the obvious choice.

For true flagship features, you’ll have to splurge on the 9 Pro instead. It comes with a QHD+ screen with an adaptive 120Hz refresh rate. You get the same refresh rate with the OnePlus 9, but it’s not adaptive, and the resolution maxes at FHD+. The OnePlus 9 Pro also gets flagship extras like an IP68 rating for dust and water resistance and super-fast 50W wireless charging (with a proprietary dock).

Sure, OnePlus has added wireless charging to the standard OnePlus 9 as well, but with only fast, not super-fast, wireless charging capped at 15W. It should be noted that the T-Mobile version of the OnePlus 9 does have an IP rating, so if you want that guarantee you may want to buy through the carrier in the US.

Samsung Galaxy S21 vs S21 Plus vs S21 Ultra 2 1
David Imel / Android Authority

The Galaxy S21 series follows a similar pattern. The Samsung Galaxy S21 and Galaxy S21 Plus are quite similar, with the display size and battery capacity the only differences. Flat Full HD+ displays, the Snapdragon 888 (or Exynos 2100 in global markets) processing package, 8GB of RAM, up to 256GB of storage, and an identical camera setup completes the picture.

The Galaxy S21 Ultra is the one you want to kick things up a notch. The display is curved and with a higher QHD+ resolution. It’s the same processor, but you can max out at 16GB of RAM and 512GB of storage. The Galaxy S21 Ultra is also the first Galaxy S phone to offer S Pen support. Nevertheless, you won’t get a built-in slot for the stylus, and unlike the Galaxy Note series, you’ll have to buy it separately.

As for charging, all three phones support 25W Power Delivery, but you won’t get an adapter in the box (check out our guide for more on what adapter you need). They also all support 15W wireless charging.

If fast charging is important to you, then the OnePlus 9 series is the obvious choice. Unfortunately, the battery life falls short when compared to the Galaxy S21 devices that comfortably last a couple of days, if not longer. When the display is set at QHD+ with a 120Hz refresh rate, Eric found that the OnePlus 9 Pro barely lasted a day with average usage in his review. The OnePlus 9 wasn’t as bad, but super-fast charging is certainly a saving grace with these phones.

However, it’s important to note that OnePlus has released a bunch of software updates since the phones launched that brought some improvements to battery life. It’s still not as good as the Samsung flagships, but definitely better than what it was when the phones were released.

OnePlus 9 review cameras
Robert Triggs / Android Authority

Let’s talk about the cameras, because OnePlus really wants you to. And with good reason, at least in the case of the OnePlus 9 Pro. In the past, our biggest issues with OnePlus’ phones have always been in the camera department. It was a compromise that was easier to accept during its “flagship killer” days, but OnePlus really needed to step up its game to take on the big boys. The OnePlus 9 Pro delivers.

Related: The best camera phones you can get

A new, high-quality 48MP Sony lens is joined by an excellent 50MP wide-angle shooter and a serviceable 8MP telephoto unit. There’s also a 2MP depth sensor to help with portrait mode. Boosting this hardware is Hasselblad’s software tweaks to provide accurate and fantastic-looking photos. The camera isn’t perfect (no smartphone camera is), but OnePlus finally has a winner on its hands that it can be proud of, especially if you like pristine color accuracy in your snaps.

Check out our shootouts below for more:

The OnePlus 9’s camera setup isn’t nearly as impressive, which is unfortunate. It makes sense though, considering the price difference between the two. There’s no telephoto lens here, and even though the primary lens has the same specs, it’s older hardware. You still get Hasselblad’s software to handle the final touches, so you can expect to get excellent color accuracy and great-looking shots here as well.

On the other hand, Samsung is one of the best in the smartphone camera game right now. The Samsung Galaxy S21 and S21 Plus come with a 12MP wide-angle lens, a 12MP ultra-wide angle shooter, and a 64MP telephoto lens. These are the same as found on the Galaxy S20 series, but they still hold up surprisingly well.

The OnePlus 9 Pro has upped the brand's camera game, but Samsung is still ahead.

In contrast, the Galaxy S21 Ultra bumps the primary telephoto to 108MP and tacks on a second 10MP telephoto as well. Unsurprisingly, the entire lineup can shoot excellent photos and videos. The Galaxy S21 Ultra is the most versatile of the lot, and its telephoto lens is truly impressive. The cameras run into usual issues with low-light photography, but overall, these are among the best camera phones around. Check out our shootouts below for more.


Price

  • OnePlus 9: $729/£629/€699/Rs. 49,999
  • OnePlus 9 Pro: $969/£829/€899/Rs. 64,999
  • Samsung Galaxy S21: $799/£769/€849/Rs. 69,999
  • Samsung Galaxy S21 Plus: $999/£949/€1,049/Rs. 81,999
  • Samsung Galaxy S21 Ultra: $1,199/£1,149/€1,249/Rs. 105,999

The OnePlus 9 series might smash OnePlus’ price ceiling thanks to the OnePlus 9 Pro, but it still manages to be cheaper than the Galaxy S21 series overall, while offering similar features and specifications. The OnePlus 9 and OnePlus 9 Pro start at $729 and $969, respectively. Meanwhile, the Galaxy S21 is priced starting at $799, the S21 Plus starts at $999, and the S21 Ultra will set you back $1,199.


OnePlus 9 vs Samsung Galaxy S21: Which should you buy?

OnePlus 9 Pro vs Samsung Galaxy S21 Ultra 1
Luke Pollack / Android Authority

The OnePlus 9 and OnePlus 9 Pro still undercut the Galaxy S21 series in price, but the difference is getting smaller and smaller every year. Comparing specific phones, the OnePlus 9 takes on the standard Galaxy S21. You get similar specs and features across the board, so it’s a toss-up between the two, at least on paper. The S21 has the benefit of dust and water resistance and a better overall camera experience, but the OnePlus 9 gets you those blazing-fast charging speeds and OnePlus’ elegant Oxygen OS software.

If you can afford it, Samsung's top-of-the-line Galaxy S21 Ultra is the best of the lot. But the $200 saved with the OnePlus 9 Pro is difficult to ignore.

The OnePlus 9 Pro is a better option than the S21 Plus. You get a higher resolution display, arguably better camera setup, more RAM if you want it. On the other hand, it fails to match the sheer overkill that is the Galaxy S21 Ultra. If you can afford it, Samsung’s top-of-the-line phone is the best of the lot. However, for all the S21 Ultra offers, the more than $200 saved with the OnePlus 9 Pro is difficult to ignore.