Samsung Galaxy S21 Series: Features & Specs Overview

Samsung Galaxy S21 / S21+ / S21 Ultra / S21 FE

1. Basic Overview

The Samsung Galaxy S21 series is a flagship Android smartphone lineup developed and marketed by Samsung Electronics, unveiled on January 14, 2021, at the virtual Galaxy Unpacked event. Positioned as the successor to the Galaxy S20 series, the lineup includes four models tailored to diverse user segments: the compact Galaxy S21 (SM-G991B), mid-sized Galaxy S21+ (SM-G996B), premium Galaxy S21 Ultra (SM-G998B), and the fan – focused Galaxy S21 FE (Fan Edition) (SM-G990B), which launched later in January 2022 as a more affordable alternative to the core S21 models.

The S21 series marked key hardware refinements, including a redesigned Contour Cut camera module (integrated into the frame for a seamless look) and optimized 5G performance. All models launched with Android 11 (One UI 3.1) and received software updates up to Android 14 (One UI 6.1), with Samsung extending security patch support for up to five years—a major upgrade for the Android ecosystem. The series was succeeded by the Galaxy S22 lineup in February 2022, but it remains a popular choice in the refurbished market, especially the S21 Ultra (lauded for its S Pen support) and S21 FE (valued for its balanced features and price).

2. Key Hardware Specifications (Global Variants: SM-G991B/SM-G996B/SM-G998B/SM-G990B)

Component	Galaxy S21 (SM-G991B)	Galaxy S21+ (SM-G996B)	Galaxy S21 Ultra (SM-G998B)	Galaxy S21 FE (SM-G990B)
Display	6.2-inch Dynamic AMOLED 2X; FHD+ (2400×1080); 421 ppi; 120 Hz adaptive refresh rate; HDR10+; 1300 nits peak brightness	6.7-inch Dynamic AMOLED 2X; FHD+ (2400×1080); 394 ppi; 120 Hz adaptive refresh rate; HDR10+; 1300 nits peak brightness	6.8-inch Dynamic AMOLED 2X; QHD+ (3200×1440); 515 ppi; 1–120 Hz adaptive refresh rate (LTPO panel); HDR10+; 1500 nits peak brightness	6.4-inch Dynamic AMOLED 2X; FHD+ (2340×1080); 411 ppi; 120 Hz adaptive refresh rate; HDR10+; 1200 nits peak brightness
Processor	Samsung Exynos 2100 (Octa-core: 1×2.9 GHz Cortex-X1 + 3×2.8 GHz Cortex-A78 + 4×2.2 GHz Cortex-A55) / Qualcomm Snapdragon 888 (regional variants)	Same as Galaxy S21	Same as Galaxy S21	Same as Galaxy S21
Memory (RAM)	8 GB LPDDR5 (non-upgradable)	8 GB LPDDR5 (non-upgradable)	12 GB / 16 GB LPDDR5 (non-upgradable)	6 GB / 8 GB LPDDR5 (non-upgradable)
Storage Options	128 GB / 256 GB UFS 3.1 (non-expandable)	128 GB / 256 GB / 512 GB UFS 3.1 (non-expandable)	128 GB / 256 GB / 512 GB / 1 TB UFS 3.1 (non-expandable)	128 GB / 256 GB UFS 3.1 (non-expandable)
Rear Camera System	Triple-camera setup:- 12MP Wide: f/1.8, OIS, Dual Pixel AF- 64MP Telephoto: f/2.0, OIS, 3x optical zoom- 12MP Ultra-wide: f/2.2, 120° FOVFeatures: 8K@24fps video, 4K@60fps video, 30x Space Zoom	Same as Galaxy S21	Quad-camera setup:- 108MP Wide: f/1.8, OIS, Nonacell pixel binning- 10MP Telephoto 1: f/2.4, OIS, 3x optical zoom- 10MP Telephoto 2: f/4.9, OIS, 10x optical zoom- 12MP Ultra-wide: f/2.2, 120° FOVFeatures: 8K@24fps video, 4K@60fps video, 100x Space Zoom, laser AF	Triple-camera setup:- 12MP Wide: f/1.8, OIS, Dual Pixel AF- 8MP Telephoto: f/2.4, OIS, 3x optical zoom- 12MP Ultra-wide: f/2.2, 120° FOVFeatures: 4K@60fps video, 30x Space Zoom
Front Camera	10MP: f/2.2, AF, 4K@30fps video	Same as Galaxy S21	40MP: f/2.2, AF, pixel binning (10MP output), 4K@60fps video	32MP: f/2.2, AF, 4K@30fps video
Battery	4,000 mAh non-removable Li-ion; 25W wired fast charging; 15W wireless charging; reverse wireless charging (4.5W)	4,800 mAh non-removable Li-ion; 25W wired fast charging; 15W wireless charging; reverse wireless charging (4.5W)	5,000 mAh non-removable Li-ion; 25W wired fast charging; 15W wireless charging; reverse wireless charging (4.5W)	4,500 mAh non-removable Li-ion; 25W wired fast charging; 15W wireless charging; reverse wireless charging (4.5W)
Connectivity	5G (sub-6 GHz / mmWave, regional); Wi-Fi 6E; Bluetooth 5.2; NFC; USB-C 3.2; GPS/GLONASS/Galileo/QZSS	Same as Galaxy S21	Same as Galaxy S21 + S Pen support (Bluetooth pairing for gestures)	Same as Galaxy S21
Dimensions & Weight	151.7 × 71.2 × 7.9 mm; 169 grams	161.5 × 75.6 × 7.8 mm; 200 grams	165.1 × 75.6 × 8.9 mm; 227 grams	155.7 × 74.5 × 7.9 mm; 177 grams
Build & Durability	Gorilla Glass Victus (front); plastic back; aluminum frame; IP68 water/dust resistance	Gorilla Glass Victus (front/back); aluminum frame; IP68 water/dust resistance	Gorilla Glass Victus (front/back); aluminum frame; IP68 water/dust resistance	Gorilla Glass Victus (front); plastic back; aluminum frame; IP68 water/dust resistance
Security & Sensors	Ultrasonic in-display fingerprint sensor; facial recognition; accelerometer; gyro; proximity; barometer	Same as Galaxy S21	Same as Galaxy S21 + laser AF sensor	Same as Galaxy S21

3. Core Software & Feature Highlights

3.1 Hardware – Centric Innovations

LTPO Display (S21 Ultra Exclusive): The S21 Ultra was the first Galaxy S model to feature a Low-Temperature Polycrystalline Oxide (LTPO) panel, which adjusted the refresh rate dynamically from 1 Hz to 120 Hz. This technology balanced smooth performance (120 Hz for scrolling/gaming) and battery efficiency (1 Hz for static content like e-books), a feature that later became standard on Samsung’s premium devices.
S Pen Compatibility (S21 Ultra Exclusive): Breaking from Galaxy Note traditions, the S21 Ultra added support for the S Pen (sold separately), enabling precision tasks like note-taking, photo editing, and gesture control. While it lacked the Note’s integrated S Pen slot, it laid the groundwork for the S Pen – centric Galaxy S Ultra models that followed.
Contour Cut Camera Design: All S21 models featured a camera module that merged seamlessly with the aluminum frame, eliminating the protruding “camera bump” of the S20 series and improving grip comfort. The S21 and S21 FE used a plastic back to reduce weight and cost, while the S21+ and S21 Ultra retained glass backs for premium feel.

3.2 Camera & Imaging Upgrades

Dual Telephoto Lenses (S21 Ultra): The S21 Ultra’s 3x and 10x optical zoom lenses enabled sharp 100x Space Zoom, with AI stabilization reducing blur at high magnification. The 108MP wide sensor delivered detailed photos, especially in well-lit conditions, while pixel binning (9-in-1) improved low-light performance by producing 12MP images with larger pixel sizes.
8K Video & Director’s View: All models supported 8K video recording, and the Director’s View feature let users switch between different camera lenses (wide, ultra-wide, front) in real time while recording, giving creators more flexibility.
Enhanced Night Mode: Samsung optimized AI processing for Night Mode, reducing noise and preserving detail in low-light photos—an improvement over the S20 series’ sometimes over-processed dark shots.

3.3 Software & Ecosystem Features

One UI 3.1: Based on Android 11, One UI 3.1 introduced a more streamlined interface, with improved one-handed navigation, customizable widgets, and enhanced privacy controls (e.g., permission monitoring for apps accessing camera/microphone).
Samsung DeX: The S21 series supported wireless DeX, allowing users to connect to a compatible TV or monitor without a cable, transforming the smartphone into a desktop-like workstation for productivity tasks.
5-Year Security Updates: Samsung’s commitment to five years of security patches and three major Android updates was a game-changer for the Android ecosystem, addressing long-standing criticism of fragmented software support.

4. Market Reception & Controversies

4.1 Critical Acclaim

The S21 Ultra was widely praised as the best Galaxy S model to date, with reviewers highlighting its LTPO display, S Pen support, and versatile camera system as flagship-defining features.
The S21 FE was lauded for its value proposition, offering most of the core S21 features (120 Hz display, flagship processor, IP68 rating) at a lower price point, making it a favorite among budget-conscious power users.
The Exynos 2100/Snapdragon 888 processors delivered strong performance for gaming and multitasking, though thermal management varied by region.

4.2 Controversies

Plastic Back on S21/S21 FE: Many users criticized Samsung for using plastic backs on the base S21 and S21 FE, arguing that it felt cheap for a flagship lineup—especially compared to the glass backs of the S20 series.
No Charger in the Box: Following Apple’s lead, Samsung removed the charging adapter from all S21 series packaging, citing environmental reasons. Critics argued this was a cost-cutting measure, forcing users to purchase chargers separately.
Thermal Throttling: Some users reported that the Snapdragon 888 variant of the S21 series suffered from thermal throttling during intensive tasks (e.g., gaming, 8K video recording), leading to reduced performance under sustained load. Samsung released software updates to mitigate this issue, but results were mixed.
S21 FE Delays: The S21 FE’s launch was delayed by several months due to global chip shortages, disappointing fans who were expecting a late-2021 release alongside the core S21 models.

5. Legacy & Positioning

Android Software Support Benchmark: Samsung’s 5-year security update promise for the S21 series raised the bar for the entire Android industry, prompting other manufacturers like Google, OnePlus, and Xiaomi to extend their software support policies.

S Pen Integration in Galaxy S Series: The S21 Ultra’s S Pen support blurred the line between Galaxy S and Galaxy Note lineups, leading Samsung to discontinue the Note series in 2022 and make S Pen a staple feature of subsequent S Ultra models (S22 Ultra, S23 Ultra).

LTPO Display Standardization: The S21 Ultra’s LTPO panel set a new benchmark for premium smartphone displays, with competitors like Apple (iPhone 13 Pro) and Google (Pixel 7 Pro) adopting similar technology in their flagship devices.

Value-Focused Fan Editions: The S21 FE solidified the “Fan Edition” concept as a key part of Samsung’s product strategy, proving that a mid-priced flagship with core premium features could drive strong sales. Subsequent models like the S22 FE and S23 FE followed this formula.