Samsung Galaxy S21 vs. Galaxy S20: The biggest changes

Samsung Galaxy S21 vs Galaxy S20
(Image credit: Tom's Guide)

This Samsung Galaxy S21 vs. Galaxy S20 face-off looks at the similarities and differences between the two generations. Although the Samsung Galaxy S21 didn't get a radical redesign, it would be wrong to think of the Galaxy S21 as a "more of the same"-style update.

While many of the improvements are what you might expect — a faster processor, updated UI and better battery efficiency — you might be surprised that one of the new models has S Pen support and dual telephoto lenses. Did we mention all the new phones cost $200 less than 2020's comparable Samsung Galaxy S20 models?

We'll need to conduct a full review of the Galaxy S21 to gauge its performance against the S20 — you can read our Galaxy S21 review, Galaxy S21 Plus review, and Galaxy S21 Ultra review. while our testing continues. Still, we know enough to compare the 2021 flagships with the current handsets Samsung offers. Here's how the Samsung Galaxy S21 vs. Galaxy S20 showdown is shaping up so far.

Samsung Galaxy S21 vs. Galaxy S20: Specs

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Row 0 - Cell 0 Galaxy S21Galaxy S21 PlusGalaxy S20Galaxy S20 Plus
Screen size6.2-inch Dynamic AMOLED (2400 x 1080; 48Hz - 120Hz)6.7-inch Dynamic AMOLED (2400 x 1080; 48Hz-120Hz)6.2-inch QHD+ AMOLED, 120HZ6.7-inch QHD+ AMOLED, 120HZ
CPUSnapdragon 888Snapdragon 888Snapdragon 865Snapdragon 865
Storage128GB, 256GB128GB, 256GB128GB128GB, 512GB
Rear camerasUltra wide: 12MP; Main: 12MP; Telephoto: 64MPUltra wide: 12MP; Main: 12MP; Telephoto: 64MPUltra wide: 12MP; Main: 12MP; Telephoto: 64MPUltra wide: 12MP; Main: 12MP; Telephoto: 64MP; VGA time-of-flight sensor
Battery size4,000 mAh4,800 mAh4,000 mAh4,500 mAh
ColorsPhantom Violet, Phantom Gray, Phantom Pink, Phantom WhitePhantom Violet, Phantom Silver, Phantom BlackCosmic Gray, Cloud Blue, Cloud PinkCosmic Gray, Cosmic Black, Cloud Blue

Samsung Galaxy S21 vs. Galaxy S20: Price and availability

Samsung gave a price cut to its S series this year. The Samsung Galaxy S21 starts at $799, while the Galaxy S21 Plus starts at $999 and the top-shelf Galaxy S21 Ultra costs $1,199. Each of these starting prices apply to 128GB storage versions of Samsung's new smartphones. You can upgrade to 256GB by adding another $50 to the cost.

These new prices are $200 less than what Samsung charged for the comparable Galaxy S20 models. You might recall the $999 starting price for the Galaxy S20, followed by the $1,119 Samsung Galaxy S20 Plus and $1,399 Samsung Galaxy S20 Ultra.

In terms of availability, the Galaxy S21 arrived earlier than the S20 debuted. Samsung held its S20 event in February 2020, with the phones arriving a few weeks later. The S21 was announced on January 14, with orders shipping on January 29.

Samsung Galaxy S21 vs. Galaxy S20: Design and models

The Galaxy S20 family debuted with three models in three different sizes (at least until the Samsung Galaxy S20 FE came along), and Samsung has continued with the big/bigger/biggest approach for the S21 lineup. 

Galaxy S21

Galaxy S21 render (Image credit: Samsung)

Samsung's new phones look a lot like the old ones with a full-screen display interrupted only by a punch-hole cutout in the center of the screen. The S21 and S21 Plus feature straighter edges, while the S21 Ultra's display has more of a curve to it.

The biggest visual difference between the S20 and S21 phones in the camera array. This year, it's designed to blend into the metal frame around the phone. Samsung calls this the Contour Cut camera housing, and we think it looks pretty sharp.

Samsung Galaxy S21 vs. Galaxy S20

Samsung Galaxy S20 family (Image credit: Tom's Guide)

Samsung Galaxy S21 vs. Galaxy S20: Display

The marquee feature introduced with the Galaxy S20 lineup — a display that refreshes at a faster rate for smoother scrolling and more immersive viewing — gets a major improvement with the Galaxy S21.

Galaxy S21

(Image credit: Samsung)

The Galaxy Note 20 Ultra released at the end of summer also featured a 120Hz refresh rate, but added the ability to dynamically adjust that rate based on your on-screen activity. That means when you're doing things like looking at static images, the display can adjust to a slower refresh rate, saving on battery. The Galaxy S21 and S21 Plus follow that trend with variable refresh rates that adjust from 120Hz down to 48Hz. (The S21 Ultra has an even wider range, scaling down to 10Hz.)

You no longer have the option to choose between a QHD+ resolution at 60hz or Full HD+ at 120Hz with the S21 and S21 Plus. Both are fixed at Full HD+ and use the dynamic 120Hz refresh rate, though you can opt to drop down to 60Hz. The S21 Ultra does offer the full QHD+ experience with a dynamic refresh rate. 

Samsung Galaxy S21 vs. Galaxy S20: Cameras

Other than fast-refreshing displays, no Galaxy S20 feature commanded as much attention as the cameras on those older phones — particularly the high-end array Samsung introduced with the Galaxy S20 Ultra. That particular model featured a 108MP main camera along with a zoom lens capable of delivering a 100x "Space Zoom" for greater details on shots. Unfortunately, the S20 Ultra camera also ran into some autofocus troubles triggered in some part by those demanding specs.

Samsung Galaxy S21 vs Galaxy S20

Galaxy S20 Plus (Image credit: Tom's Guide)

Samsung learned its lessons, and the Galaxy S21 Ultra reflects that. The 108MP main sensor returns in the new version of the phone, as well the telephoto lens and its 100x zooming ability. For optical zooming, the S21 Ultra features two telephoto lenses — one with a 3x zoom and the other capable of 10x optical zoom. 

Galaxy S21 Plus

(Image credit: Tom's Guide)

This time, though, Samsung has included laser autofocus to address any focusing issues; the feature certainly helped the Galaxy Note 20 Ultra produce great zoom shots.

In addition to those cameras and sensors, the Galaxy S21 Ultra rounds out the camera array with an ultra-wide-angle lens. This gives Samsung's most expensive S21 model a four-camera array on the back. Meanwhile, the S21 and S21 Plus feature a more common three-camera setup — a 12MP main lens, 12MP ultra-wide shooter and a 64MP telephoto lens. Like the S21 Ultra, these two phones add a Zoom Lock feature that keeps zoomed shots in better focus — an improvement over the Galaxy S20 lineup.

Samsung Galaxy S21 vs. Galaxy S20: Performance

The Galaxy S20 family featured the Snapdragon 865 system-on-chip, at least for phones released in the U.S. (In other parts of the world, Samsung used its own Exynos 990 processor.) The Galaxy S21 continues Samsung's tradition of grabbing Qualcomm's best mobile processor available for its Galaxy S series, by introducing the Snapdragon 888 in its new flagship phones.

Samsung Galaxy S21 vs Galaxy S20

(Image credit: Qualcomm)

The Snapdragon 888 promises a number of enhancements for mobile gaming, photography and artificial intelligence. For performance, Qualcomm says the new chipset's Kryo 680 CPU will deliver up to a 25% boost in overall performance compared to the Snapdragon 865. The Adreno 660 GPU should render graphics 35% faster than the previous generation.

The Galaxy S21 powered by the Snapdragon 888 (or the Exynos 2100 for models outside the U.S.) handily outperforms the Galaxy S20 rather handily and narrows the performance gap with the A14 Bionic-powered iPhone 12. But the A15-powered iPhone 13 jumped quite a bit ahead of the Galaxy S21.

Samsung Galaxy S21 vs. Galaxy S20: Battery life and charging

On the surface, there's not much difference between the battery sizes in the Galaxy S21 models and last year's S20 lineup. The Galaxy S21 has a 4,000 mAh battery while the S21 Ultra relies on a 5,000 mAh power pack. These are the same battery capacities found in the comparable S20 models. Only the Galaxy S21 Plus received a bigger battery — a 4,800 mAh pack replaces the 4,500 mAh module found in the S20 Plus.

Samsung Galaxy S21 vs. Galaxy S20

Galaxy S20 (Image credit: Future)

Ultimately, though, the lack of any change to battery size may not matter when it comes to battery life, as least for the Galaxy S21. With that model featuring a less demanding resolution, power consumption falls off for the Galaxy S21 — as long as you disable the adaptive refresh rate. (The Galaxy S21 turned in a pitiful result in its 120Hz mode in our battery life test.)

Throw in a more efficient chipset — the Snapdragon 888 is expected to feature better power efficiency than the Snapdragon 865 — and the S21 models last longer on a charge than the last round of Galaxy flagships.

Samsung did not include a charger in the box with its new phones, mirroring a move Apple made with the iPhone 12. You may recall Samsung put out an ad mocking Apple's decision, so it may be worth asking who's laughing now.

Samsung Galaxy S21 vs. Galaxy S20: Software and S Pen

The Galaxy S21 phones arrived with Android 11 pre-installed with Android 12 ready and raring to go. That means a new skin on top of Android, with the new One UI 4 interface introducing tweaks more UI customization and privacy features.

Samsung Galaxy S21 vs. Galaxy S20

Galaxy S21 Ultra render (Image credit: LetsGoDigital/Giuseppe Spinelli)

The biggest edge the Galaxy S21 Ultra holds over the S20 series is support for Samsung's S Pen, the stylus previously limited to Galaxy Note devices. It's the first non-Galaxy Note phone to offer S Pen support, though you'll have to purchase the stylus separately. You'll also want a case for storing the S Pen.

Samsung Galaxy S21 Ultra

(Image credit: Samsung)

Samsung Galaxy S21 vs. Samsung Galaxy S20: What about the Galaxy S21 FE and Galaxy S22?

The Galaxy S21 FE is official, offering much of what makes the Galaxy S21 great all for $699. It's not perfect and there are noticeable corners cut to keep the cost down. You're probably better off finding a good deal on a Galaxy S21.

But the Galaxy S22 is right around the corner, so it's worth waiting to see what Samsung is going to do next. If nothing else, you'll probably find an S21 cheaper, much like what happened with the S20 in 2021.

Samsung Galaxy S21 vs. Samsung Galaxy S20: Outlook

The lower entry prices and stronger performance certainly give the Galaxy S21 phones an edge over their S20 counterparts. While the Galaxy S21 and Galaxy S21 Plus are modest upgrades, the Galaxy S21 Ultra is leagues better than the S20 Ultra.

As we look forward into 2022, we're of course considering the next big thing: the Galaxy S22. We might be in for some interesting changes, but that's not the point here. With the Galaxy S21, you get a great bang for your buck, especially if you find a good carrier or trade-in deal.

Philip Michaels is a Managing Editor at Tom's Guide. He's been covering personal technology since 1999 and was in the building when Steve Jobs showed off the iPhone for the first time. He's been evaluating smartphones since that first iPhone debuted in 2007, and he's been following phone carriers and smartphone plans since 2015. He has strong opinions about Apple, the Oakland Athletics, old movies and proper butchery techniques. Follow him at @PhilipMichaels.