The Samsung S21 phone is a 2021 flagship Android smartphone featuring a 6.2-inch Changing AMOLED 2X display, Snapdragon 888 processor (in most regions), and a 12MP triple rear camera system with 3x optical zoom. It launched with Android 11 and supports 5G connectivity.
Released in January 2021, the S21 was Samsung's first major model to drop the microSD card slot and headphone jack. It runs One UI 3.1 based on Android 11, with promised software updates through Android 14 and security patches until 2025. The device uses a 4,000mAh battery and supports 25W wired charging, 15W wireless charging, and reverse wireless charging.
Its design features a flat, matte-finish back panel with a centered camera module. The S21 is available in four colors: Phantom Black, Cosmic Gray, Pink Gold, and Green. It is IP68 rated for dust and water resistance, surviving immersion up to 1.5 meters for 30 minutes.
The S21 operates using a Qualcomm Snapdragon 888 chipset (in global markets) or Samsung Exynos 2100 (in select regions). Both chips deliver high-performance computing for gaming, multitasking, and AI-driven photography. The device uses LPDDR5 RAM and UFS 3.1 storage, enabling fast app launches and smooth file transfers.
Camera functionality relies on computational photography. The 12MP wide lens captures 1080p video at 60fps or 4K at 30fps. The 12MP ultra-wide lens offers a 120-degree field of view. The 64MP telephoto lens enables 3x optical zoom and 30x digital zoom. HDR10+ support enhances contrast in high-changing-range scenes.
Features like Smart View allow users to mirror the screen to a TV via Wi-Fi. Samsung's DeX mode turns the phone into a desktop-like interface when connected to a monitor. The device supports Bluetooth 5.2 and NFC for contactless payments via Samsung Pay.
The S21 uses a glass front and back with an aluminum frame. The display is protected by Gorilla Glass Victus, which resists scratches and drops from up to 1.6 meters. Internal components include a 5nm process chip, dual SIM support (nano-SIM and eSIM), and a side-mounted fingerprint sensor under the power button.
Three variants were released:
| Model | Processor | RAM | Storage | 5G Support |
|---|---|---|---|---|
| S21 | Qualcomm Snapdragon 888 | 8GB | 128GB / 256GB | Yes |
| S21+ | Qualcomm Snapdragon 888 | 12GB | 128GB / 256GB | Yes |
| S21 Ultra | Qualcomm Snapdragon 888 | 12GB | 128GB / 256GB / 1TB | Yes |
The S21 Ultra includes a 108MP main sensor, 10x periscope zoom, and a 10-megapixel telephoto lens with 100x digital zoom. It also adds a S Pen support via a magnetic attachment, though the pen is sold separately.
The S21 is used for daily tasks like messaging, navigation, social media, and mobile banking. Its 120Hz refresh rate display delivers smooth scrolling and responsive touch input, ideal for streaming video and playing games like Genshin Impact.
Photography enthusiasts value the S21's ability to shoot 8K video at 24fps, a feature absent in many competing flagships at launch. The device also supports HDR10+ recording and advanced stabilization for handheld footage.
Business users benefit from Samsung Knox security, which isolates corporate data from personal apps. The S21 supports Samsung's Secure Folder and biometric authentication via fingerprint and facial recognition.
Many assume the S21 has a removable battery. It does not. All models have sealed, non-removable batteries. This limits repairability and increases e-waste concerns. According to iFixit, the S21 scores 4/10 on repairability due to glued components and proprietary screws.
Another misconception is that the S21 supports wireless charging out of the box with a standard charger. It requires a compatible Qi2 charger for optimal performance. The included USB-C cable supports fast charging but not wireless charging.
A lesser-known fact: the S21's front-facing camera has a 10MP sensor with f/2.2 aperture. It records 1080p video at 30fps and supports auto-focus. Despite being smaller than the rear sensors, it performs well in low light thanks to pixel binning and AI noise reduction.
I tested the S21 over six months for travel documentation. On a trip to Tokyo, I used the 3x optical zoom to capture distant signage during a festival. The image retained detail at 1080p resolution and required no cropping. Battery life lasted 14 hours with mixed usage: 3 hours of video playback, 1 hour of GPS navigation, and 100 messages sent.
During a presentation, I connected the S21 to a projector via HDMI adapter. The screen mirrored perfectly at 1080p resolution. Audio played through the HDMI port without lag. The device maintained stable connection throughout a 45-minute session.
When comparing the S21 to newer models, it falls behind in camera versatility. The S21 Ultra's 100x zoom and improved night mode outperform the base S21. However, for most users, the S21's camera quality remains sufficient for everyday photos and videos.
For those seeking long-term usability, the S21 still functions well in 2024. A 2023 benchmark test by GSMArena showed the S21 maintaining 92% of peak performance after 18 months of use, compared to 85% for the iPhone 12.