When Samsung launched the Galaxy S21 in early 2021, it redefined what a flagship smartphone could be: powerful, compact, and surprisingly affordable compared to its Ultra counterpart. Even in 2025, the Galaxy S21 remains a relevant and reliable Android device, continuing to impress users with its premium design, capable performance, and refined software. In this full review, we’ll take a deep dive into the design, display, camera, performance, battery, and long-term usability of the Samsung Galaxy S21 and find out why it’s still a great choice in 2025 for those seeking a flagship feel without breaking the bank.
Design and Build Quality
Samsung struck a fine balance between style, comfort, and durability with the Galaxy S21. Unlike the glass back found on the S21 Ultra, the regular S21 came with a polycarbonate (plastic) back, which surprisingly felt premium thanks to its matte texture and lightweight construction. It was built to be compact and ergonomic, making it one of the most comfortable phones to hold and use with one hand, a rarity in today’s smartphone market.
- Dimensions: 151.7 x 71.2 x 7.9 mm
- Weight: 171 g
- Material: Armor Aluminum frame, polycarbonate back
- Water Resistance: IP68 certified
The Contour Cut Camera housing, blending seamlessly into the frame, gave the Galaxy S21 a distinctive and futuristic look that inspired later Galaxy designs, including the S22 and S23.
Display
Samsung has always been the undisputed leader in display technology, and the Galaxy S21 was no exception. The 6.2-inch Dynamic AMOLED 2X panel delivered breathtaking color accuracy, deep contrast, and smooth animations.
- Display Type: Dynamic AMOLED 2X
- Resolution: FHD+ (2400 × 1080 pixels)
- Refresh Rate: Hz adaptive
- Brightness: Up to 1300 nits
The adaptive refresh rate intelligently switched between 48 Hz and 120 Hz, ensuring both buttery-smooth performance and efficient power use. Whether you were streaming HDR videos, browsing photos, or gaming, the Galaxy S21’s display looked stunning from every angle.
Performance and Hardware
Under the hood, the Galaxy S21 came powered by either Snapdragon 888 (US) or Exynos 2100 (global). Both were 5 nm flagship processors, offering blazing-fast performance and improved efficiency over the S20 series.
- Processor: Snapdragon 888 / Exynos 2100
- RAM: 8GB
- Storage: 128GB / 256GB (no microSD support)
- OS: Android 11 (upgradable to Android 14 with One UI 6.1)
Even in 2025, the Galaxy S21 continues to deliver solid performance for everyday use; multitasking, gaming, and streaming are all handled effortlessly. Samsung’s One UI optimizations and consistent updates have kept it running smooth and responsively.
Camera: Flagship Imaging for Everyday Users
The Galaxy S21 featured a versatile triple-camera setup, perfectly balancing performance and practicality. It offered crisp, vibrant photos across lighting conditions, thanks to Samsung’s excellent image processing and AI tuning.
- Main Camera: 12MP (f/1.8, Dual Pixel AF, OIS)
- Ultra-Wide: 12MP (f/2.2, 120° FoV)
- Telephoto: 64MP (3x hybrid zoom, OIS)
- Front Camera: 10MP (f/2.2)
In daylight, shots came out sharp and color-rich. Night mode handled low light surprisingly well, producing bright and detailed images. The 8K video recording feature, though more of a showcase at the time, demonstrated Samsung’s ambition for pro-level video capture.
Battery Life and Charging
Battery life was decent, though not class-leading. The 4000 mAh cell provided a full day’s use under normal conditions, thanks to Samsung’s software optimizations and adaptive refresh rate.
- Battery Capacity: mAh
- Charging: 25W wired, 15W wireless, 4.5W reverse wireless
While Samsung removed the charger from the box (a controversial move at the time), the S21 charged relatively fast with a compatible 25W adapter.
Software and One UI Experience
The Galaxy S21 shipped with Android 11 and One UI 3.1, introducing cleaner visuals, better customization, and smoother animations. In 2025, it’s upgradeable to Android 14 with One UI 6.1, meaning it still feels modern and secure. Samsung’s 4-year Android update and 5-year security patch policy have ensured that even older flagships like the S21 remain relevant and protected.
Gaming and Performance Review
The Galaxy S21 handles games like PUBG Mobile, Genshin Impact, and COD Mobile effortlessly, maintaining high frame rates and stunning visuals. However, during extended gaming sessions, it may get slightly warm, a common trait for Snapdragon 888/Exynos 2100 devices.
Color Options
Samsung offered the Galaxy S21 in several elegant shades that appealed to both professional and trendy users:
- Phantom Gray
- Phantom White
- Phantom Violet
- Phantom Pink
Later limited-edition colors like Navy Blue and Red added a touch of exclusivity.
Pros and Cons of Samsung Galaxy S21
Pros:
✔ Sleek, lightweight, and premium design
✔ Gorgeous AMOLED Hz display
✔ Great all-round camera setup
✔ Smooth One UI experience
✔ Long-term software support
Cons:
❌ No charger in the box
❌ Plastic back instead of glass
❌ Average battery life
❌ No expandable storage
Samsung Galaxy S21 vs. Galaxy S22: Should You Upgrade?
If you own the Galaxy S21, the upgrade to the S22 may not be a huge leap. Both share similar design language, display size, and camera setup. The biggest difference lies in the improved main camera, better build quality, and Snapdragon 8 Gen 1 chipset in the S22. For most users, the S21 still offers flagship performance and features at a lower cost, making it a smarter buy in 2025.
Final words
Even after four years, the Samsung Galaxy S21 continues to shine as a compact flagship with reliable performance, premium design, and top-tier software support. It may lack the newer hardware of the S23 or S25, but its balanced performance and enduring quality make it a worthy daily driver in 2025.