Samsung Galaxy S21 Review

Top-end Snapdragon 888 performance, but a throttling caveat

The Galaxy S21 uses Qualcomm's Snapdragon 888, which introduced a new CPU configuration and a latest-generation Qualcomm GPU; synthetic tests reported generational improvements on GPU and CPU workloads. Reviewers running synthetic benches noted clear raw performance gains compared with prior generations.

However, multiple reports highlight that Samsung tunes the S21 out of the box for improved battery life and conservative thermal limits. Somegadgetguy documented that the phone ships with this tuning active, requiring manual adjustment in buried battery settings (described as first found three layers deep in battery stats) to show higher sustained performance in repeated benchmarks.

4000 mAh battery with wireless charging, but tuned for efficiency

The standard S21 model is equipped with a 4000 mAh battery and supports wireless charging. HotHardware and PCMag both note the smaller physical battery capacity relative to Samsung's larger S21 siblings and compared to some previous-generation flagships.

Samsung's default power tuning prioritizes battery life, which reviewers found reduces sustained performance under heavy load. That trade-off helps real-world endurance but can produce lower benchmark repeatability until users change the hidden power/performance settings or install firmware updates.

Compact 6.2-inch form factor aimed at users who prefer smaller flagships

At 6.2 inches, the S21 is Samsung's smallest standard S-series handset in this generation, a deliberate move for buyers who prefer one-handed handling. PCMag's coverage emphasized that the smaller footprint is a major selling point for users who don't want the larger S21+ or S21 Ultra.

While HotHardware calls the device 'packed with features' for its class, Samsung also pared back some hardware and polish relative to the S20 generation — a design and features trade-off aligned with the product's repositioning as a more value-focused flagship.

Usability is solid but some settings and behavior are buried

Out-of-box behavior includes Samsung's default battery and thermal tuning which reviewers labeled 'finnicky' — some benchmarkers had to duplicate work because the phone required diving into buried options to change performance tuning. The hidden control referenced in reviews sits multiple menu layers deep inside battery stats.

Community reports from Samsung's forums indicate firmware updates (a January update referenced by users) improved general stability and responsiveness for some owners, showing the device's experience can change materially with software revisions.

A repositioned flagship that trades features for a lower launch positioning

Samsung intentionally scaled back some features on the S21 relative to the S20 generation as part of a broader value-focused strategy for the S line. HotHardware reported the family-wide price repositioning and framed the standard S21 as the least expensive flagship in the trio while keeping core features like wireless charging and full 5G support.

Against competitors, PCMag highlighted that the S21 sits alongside the S21+ and S21 Ultra and coexists with the S20 FE; iPhone 12 was also named as a market rival in the contemporary reviews. That means buyers can choose a compact flagship experience on the S21, but there are still more feature-rich or differently-configured alternatives in the market.

Pros & Cons

• ✅ Equipped with Qualcomm Snapdragon 888 SoC — documented generational CPU and GPU improvements in synthetic benchmarks
• ✅ Compact 6.2-inch form factor for one-handed use compared with larger S21 siblings
• ✅ 4000 mAh battery with wireless charging and support for Sub-6 and mmWave 5G
• ✅ Out-of-the-box tuning favors battery life, which yields longer real-world endurance unless altered
• ✅ Active community and firmware updates reported to improve stability (January community update noted)

• ❌ Shipped with conservative power/thermal tuning that reviewers described as 'pre-throttled' and 'finnicky', requiring digging three menu layers deep to change
• ❌ Less feature-rich than the previous S20 generation in some areas, a deliberate trade-off by Samsung
• ❌ Smaller 4000 mAh battery capacity than larger S21 models and some prior flagships
• ❌ Benchmark repeatability affected by default power profile; reviewers had to duplicate testing to get consistent scores

How It Compares to the Competition

• Samsung Galaxy S21 Ultra — Larger, more feature-rich S21 sibling with bigger battery and higher-end camera options for power users.
• Samsung Galaxy S20 FE — An alternative Android pick highlighted by editors for balancing features and size; remains a competitive option in Samsung's lineup.
• Apple iPhone 12 — Platform-level alternative noted in contemporaneous reviews; competes on compact size and mainstream appeal with a different ecosystem and performance profile.

Who Should Buy This & Who Should Skip It

Buy it if: Buy the Galaxy S21 if you want a compact 6.2-inch flagship with the Snapdragon 888 and 5G (Sub-6/mmWave) support, wireless charging, and prefer Samsung's value-focused S-series trade-offs. It's best for users who prioritize raw single-chip performance boosts and a smaller, pocketable flagship.

Skip it if: Skip the S21 if you need the highest sustained performance out of the box (it ships with conservative power limits) or want features Samsung removed compared with the S20. Power users who want the largest battery, top-tier camera hardware, or an out-of-box unrestricted performance profile should look at the S21 Ultra or alternate models.