What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
iTechGuides is reader-supported. When you buy through links on our site, we may earn an affiliate commission. As an Amazon Associate I earn from qualifying purchases. Learn more
The Samsung Galaxy S21 5G made a strong case as a smaller, less expensive flagship when it launched in 2021: it paired a 6.2-inch adaptive 120Hz display with versatile triple rear cameras and high-end performance. The savings came with clear compromises, including a flat 1080p screen, plastic back, no microSD slot, and no charging brick in the box. A six-day hands-on review found battery life adequate, but that test is not a promise for every owner. Today, whether an S21 is worth buying depends on its price, condition, exact model and local software status.
What the Galaxy S21 5G offered at launch
Samsung announced the U.S. Galaxy S21 5G on January 14, 2021, with nationwide availability beginning January 29. The base model started at $799.99 in the U.S.; that is its historical launch price, not a guide to what a used or refurbished phone should cost today. Samsung positioned it as the compact option in the S21 family, below the larger S21+ in both size and launch price. Samsung’s U.S. launch announcement lists the original specifications.
Android Authority’s January 2021 review characterized the S21’s $800 launch price as $200 below the S20’s starting price. Its value came from retaining features such as a high-refresh-rate AMOLED screen and a dedicated telephoto camera while trimming materials, resolution and storage flexibility. That made the S21 an appealing flagship proposition at launch, but those trade-offs remain relevant when assessing a particular handset now.
Is the Galaxy S21 display good?
The S21 has a 6.2-inch flat FHD+ Dynamic AMOLED 2X display with a 2400 × 1080 resolution, HDR10+, and an adaptive refresh rate from 48Hz to 120Hz. Samsung’s diagonal measurement is 6.2 inches across the full rectangle, or 6.1 inches when accounting for rounded corners. At 171g and 71.2 × 151.7 × 7.9mm, the phone is relatively compact by flagship standards. Samsung’s specification table gives the display and dimensions.
#1 Best Overall
- Display: 6.2" AMOLED display with 120Hz refresh rate and 1300 nits brightness for vivid visuals and smooth scrolling.
- Camera: Rear dual camera system with 64MP main and 12MP ultrawide lenses for stunning photos and videos.
- Memory: 128GB internal storage and 8GB RAM for plenty of apps and files.
- Connectivity: 5G capable with support for GSM, CDMA, and Wi-Fi networks.
- Battery: 4000mAh battery provides all-day power for your daily needs.
Android Authority’s reviewer praised the screen as bright and attractive, and considered the 1080p resolution an acceptable cost-saving compromise. It is not as sharp as a higher-resolution premium S-series panel, but the flat shape is practical for users who prefer fewer curved-screen edges. The adaptive setting varies refresh rate rather than holding 120Hz constantly; the review says the standard setting does not offer a way to force 120Hz at all times.
How good are the Galaxy S21 cameras?
The rear array comprises a 12MP ultrawide camera with a 120-degree field of view, a 12MP wide camera with optical image stabilization, and a 64MP telephoto camera with phase-detection autofocus and hybrid optical 3x zoom. The front camera is 10MP. The 64MP sensor is the telephoto camera, not the phone’s main wide camera. Samsung’s launch specifications list the sensors and zoom description.
Rank #2
- The Galaxy S21 FE sports a sleek polycarbonate back with a premium matte finish that resists fingerprints and feels smooth in hand, giving it a stylish yet practical design.
This mix gives the phone more framing flexibility than a setup limited to a main and ultrawide camera: the ultrawide suits broad scenes, the stabilized wide camera is the everyday option, and the telephoto is useful for distant subjects. Android Authority’s independent review supports the configuration and launch-era positioning, but does not establish a current comparative camera ranking or a quantified image-quality verdict. For a used phone, inspect the individual lenses and test focus, stabilization and camera switching before buying.
Quick wins for a faster PC:
Repair Windows errors before they cause bigger problemsFix Now →Scan for outdated or missing drivers - takes under a minuteDriver Scan →How long does the Galaxy S21 battery last?
The S21 has a 4,000mAh battery. Android Authority tested a Verizon-supplied review unit for six days on One UI 3.1 and Android 11, with the January 2021 security patch. On the reviewer’s heaviest day, screen-on time reached 8.2 hours; that day included nearly five hours of driving navigation and around six hours of music streaming. On lighter days, the reviewer reported about 40% remaining. These are observations from one review unit and usage pattern, not a universal runtime estimate. Samsung notes that battery life varies with network, usage and other factors.
Rank #3
- 6.2 inch, 1080 x 2400 pixels, Dynamic AMOLED 2X, 120Hz, HDR10 plus, 1300nits, 4000mAh Battery
- 256GB ROM, 8GB RAM, No SD Card Slot, Qualcomm SM8350 Snapdragon 888 5G (5 nm), Octa-Core, Adreno 660
- Rear Camera: 64MP, f/2.0 plus 12MP, f/1.8 plus 12MP, f/2.2, Front Camera: 10 MP, f/2.2, Android 11, One UI 3.1
- 2G: GSM 850/900/1800/1900, CDMA 800/1900, 3G: HSDPA 850/900/1700(AWS)/1900/2100, CDMA2000 1xEV-DO, 4G LTE: 1/2/3/4/5/7/8/12/13/14/18/19/20/25/26/28/30/38/39/40/41/46/48/66/71, 5G: 2, 5, 25, 41, 66, 71, 260, 261 SA/NSA/Sub6/mmWave - Single SIM
- US Model. Compatible with Most GSM and CDMA Carriers like T-Mobile, AT andamp;T, MetroPCS, etc. Will Also work with CDMA Carriers Such as Verizon, Sprin
For charging, Android Authority’s review specification table lists up to 25W wired charging, 15W wireless charging and 4.5W reverse wireless charging. The phone did not include a charging brick in the package, so a buyer should verify whether a suitable USB-C charger is available separately. Maximum supported charging rates are not a guarantee of the speed achieved in every situation.
What are the S21’s compromises?
- Plastic rear: The back is plastic rather than glass. Android Authority’s reviewer regarded it as lighter and less prone to shattering than glass, while noting it lacks glass’s feel. The handset weighs 171g.
- 1080p resolution: The flat screen is FHD+, not the higher resolution offered by more premium S-series models. The reviewer considered this a reasonable trade-off at launch.
- No microSD expansion: Samsung listed 128GB and 256GB storage configurations, both with 8GB RAM, and the base S21 has no microSD card slot. Choose capacity with that limitation in mind.
- No charger in the box: The review reports that a charging brick is not included, despite wired charging support up to 25W.
These were part of the S21’s value-oriented design rather than hidden defects. Whether they matter depends on what you prioritize: a lightweight, smaller flagship with an adaptive display, or premium materials, expandable storage and a sharper panel.
Rank #4
- This pre-owned product has been professionally inspected, tested and cleaned by Amazon qualified vendors.
- This product is in "Excellent condition". The screen and body show no signs of cosmetic damage visible from 12 inches away.
- This product will have a battery that exceeds 80% capacity relative to new.
Is the Galaxy S21 worth buying now?
There is no reliable present-day value verdict without a current listing and a specific device to assess. New, used and refurbished stock and prices were not established here. Compare the asking price with the phone’s condition and the support and network situation for its exact model; do not treat its $799.99 launch price as a current benchmark.
Before purchasing a used or imported S21, check:
- Model and network: Confirm the full model number, supported 5G and LTE bands, carrier compatibility and whether the phone is carrier-locked. Samsung cautions that 5G availability depends on country, provider and user environment.
- Battery and physical condition: Ask about battery condition, test charging and inspect the screen, frame, rear panel, cameras and USB-C port. A six-year-old handset may have substantially different battery performance from a new review unit.
- Storage: Confirm whether it is the 128GB or 256GB version; there is no microSD slot to add capacity later.
- Software status: Check the phone’s current update screen and compare it with the official update record for the exact regional model. Update timing can vary by country and provider.
For the U.S. model SM-G991U, Samsung’s update history lists Android 15 and an update released March 19, 2026, with a January 1, 2026 security patch level. This record is evidence for that listed model only; Samsung says changes can differ by model, country and service provider, and it does not establish a future support timetable for every S21. Samsung’s SM-G991U update history is the relevant model-specific record.
Quick Recap
Galaxy S21 5G specifications
| Specification | Galaxy S21 5G |
|---|---|
| Display | 6.2-inch flat Dynamic AMOLED 2X; 2400 × 1080; adaptive 48–120Hz; HDR10+ |
| Dimensions and weight | 151.7 × 71.2 × 7.9mm; 171g |
| Memory and storage | 8GB RAM; 128GB or 256GB storage; no microSD slot |
| Rear cameras | 12MP ultrawide, 12MP wide with OIS, 64MP telephoto with hybrid optical 3x zoom |
| Front camera | 10MP |
| Battery and charging | 4,000mAh; up to 25W wired, 15W wireless and 4.5W reverse wireless charging; charging brick not included |
| U.S. launch price | $799.99; historical price for the base model at launch in 2021 |
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
