Samsung Galaxy S21 vs S21 FE — 2025 Comparison: Specs, Performance & Which to Buy

Quick snapshot — headline specs at a glance

• Release: Galaxy S21 — Jan 2021; Galaxy S21 FE — Jan 2022. 

• Display: S21 — 6.2" Dynamic AMOLED 2X, 2400×1080, 120Hz (adaptive). S21 FE — 6.4" Dynamic AMOLED 2X, 2340×1080, 120Hz. 

• Chipsets: S21 — Exynos 2100 (many regions) or Snapdragon 888 (US/China). S21 FE — Snapdragon 888 in many markets (some regions used Exynos 2100). 

• Battery: S21 — 4,000 mAh. S21 FE — 4,500 mAh. 

• Cameras: S21 — 12MP wide + 12MP ultrawide + 64MP tele (hybrid). Front 10MP. S21 FE — 12MP wide + 12MP ultrawide + 8MP tele (3×), front 32MP. 

• Charging: Both support 25W wired, ~15W wireless, and Wireless PowerShare. 

• Build: Both use a glass front; both S21 and S21 FE use reinforced plastic (polycarbonate) for the back in many trims; S21 FE typically has an aluminum frame and Gorilla Glass front. 

These short facts frame the rest of this comparison: the S21 FE nudges the S21 in a few practical ways (bigger screen, larger battery, higher-res selfie) while both share a lot of Samsung’s core hardware and software DNA.

Design & build — look, feel and durability

At first glance the two phones share Samsung’s recent design language — slim bezels, a centered punch-hole selfie camera, and a camera “island” that blends with the frame. But small choices matter:

• S21: 6.2" compact flagship, polycarbonate (often called “glasstic”) back, lighter weight (≈169–171g). It was designed as the pocket-friendly flagship in 2021. 

• S21 FE: 6.4" slightly larger footprint, metal frame, Gorilla Glass front (Victus on certain launches), and a textured plastic back that many reviewers praised for grip and durability. The FE is tuned for value and practical daily use. 

Both phones carry IP68 dust/water resistance and a solid midframe, so neither sacrifices real-world durability. The practical takeaway: if you want the smallest pocket-friendly phone choose the S21; if you prefer a larger screen without paying S22 or S23 prices, the S21 FE offers that with similar protection. 

Display & multimedia — size, speed and real use

Samsung’s Dynamic AMOLED panels remain excellent two years after release:

• Size & comfort: S21’s 6.2" screen is friendlier for one-handed use. S21 FE’s 6.4" gives more room for streaming and gaming without entering “phablet” territory. 

• Smoothness: Both screens run up to 120Hz — S21 uses an adaptive 48–120Hz stepping, while the S21 FE offers a similarly smooth 120Hz experience. Both support HDR10+. 

• Brightness & outdoors use: S21 historically peaked higher in official brightness specs, but real-world legibility is similar; modern software tuning keeps both readable in daylight. If you prioritize the absolute brightest display for outdoor shooting or navigation, check updated brightness bench tests for your region — differences are small. 

For video and games the slightly larger FE screen gives a more immersive experience; the S21 remains excellent if you prefer a compact device.

Performance — chips, real speed and thermals

Under the hood is where regional variants confuse comparisons:

• Chipsets: S21 shipped with Exynos 2100 in many global markets and Snapdragon 888 in the U.S. and others; the S21 FE mostly used Snapdragon 888 in many regions, though some SKUs used Exynos 2100. That means performance depends on the exact unit you buy. 

• Real-world differences: Benchmarks and battery tests from independent reviewers showed Snapdragon 888 generally has a small edge in sustained GPU performance and power-efficiency, while Exynos 2100 is competitive on peak CPU benches but can be a little less efficient under long gaming loads. Expect modest real-life differences — a Snapdragon S21 or S21 FE will often run cooler and sustain higher frame rates in long gaming sessions. 

What to do before buying: If performance consistency matters (mobile gaming, heavy multitasking), prefer an unlock/retail unit with a Snapdragon 888. If you're buying used or refurbished, check the SKU or the seller listing for region/chip details. 

Cameras — hardware vs software and everyday shots

Both phones lean on Samsung’s strong computational imaging, but with divergent strengths:

• Main camera: Both use a 12MP wide sensor with OIS — expect solid daytime shots with punchy color and good HDR. 

• Telephoto: S21’s telephoto is a 64MP sensor that achieves hybrid 3× zoom via cropping; S21 FE uses an 8MP telephoto with true 3× optics. In practice, S21 FE’s optical tele might look crisper at mid-range zooms, while S21’s higher-res tele can be useful for high-zoom crops but relies more on software. 

• Selfies: S21 FE’s 32MP front camera is a clear advantage for social-media-focused users and video calls; the S21’s 10MP selfie remains good but offers less resolution. 

Real-world advice: both phones will satisfy most casual photographers. If selfies matter to you or you do a lot of video calls, S21 FE has the edge. If you push zoom often, look at side-by-side sample galleries — the two phones trade minor wins depending on lighting and software processing.

Battery life & charging — who lasts longer

This is one of the clearest practical differences:

• Capacity: S21 — 4,000 mAh; S21 FE — 4,500 mAh. That 500 mAh difference translates to a meaningful boost in screen-on time for the FE in most mixed-use scenarios. 

• Charging: both support 25W wired charging (charger sold separately in the box era) and ~15W wireless charging plus Wireless PowerShare. With similar charging tech, the FE’s larger battery simply extends runtime. 

Outcome: for heavy users or travellers the FE is the safer pick for battery longevity; if you prioritize smaller size over endurance, the S21 is still acceptable with a strong day of use.

Software updates & long-term support

Software matters as much as hardware two years in:

• Update track: both phones launched on different Android versions (S21 on Android 11, S21 FE on Android 12) but Samsung has been rolling major updates broadly to the S21 family and FE models in 2023–2025. Samsung has also extended security update windows and announced longer support commitments for many Galaxy devices. Check that any used device has the latest patch and confirm region-specific update availability. 

What to check pre-purchase: verify the current One UI/Android version on a used phone and review Samsung’s official update schedule to confirm how many more OS updates and security patches are guaranteed for your specific SKU. 

Price & value in 2025 — what you can expect

Launch prices were roughly S21 $799 and S21 FE $699; in 2025 both are often available at discounted, refurbished, or certified-renewed prices. That makes them appealing choices for buyers who want flagship features without the newest-generation premium.

Value rules of thumb (2025):

• If you can find an S21 FE at or under $400–$450 refurbished with a Snapdragon 888 and good battery health, it’s a strong value pick.

• An S21 at similar refurbished prices is a fine compact alternative — prefer it if you want the smaller size or if you find a Snapdragon SKU for slightly better thermal performance.
  Prices vary by region, warranty status and condition — always check seller return policies and battery health reports.

Pros & cons — quick decision map

Samsung Galaxy S21 — Pros

• Compact 6.2" form factor fits pockets easily.

• Flagship-level display and cameras.

• Lighter weight. 

Samsung Galaxy S21 — Cons

• Smaller battery than S21 FE.

• Back is plastic — still durable but less premium. 

Samsung Galaxy S21 FE — Pros

• Larger 6.4" screen and 4,500 mAh battery for longer runtime.

• Higher-res 32MP selfie.

• Generally excellent price-to-performance ratio when discounted. 

Samsung Galaxy S21 FE — Cons

• Slightly larger size (one-handers may notice).

• Telephoto reduced to 8MP though optics remain useful. 

Best picks by user type — who should buy which phone in 2025?

• Buy the S21 if: you want a compact flagship that’s easier to pocket and handle, and you find a Snapdragon SKU for a good price. Compact size plus flagship display is its sweet spot. 

• Buy the S21 FE if: battery life, a bigger display and a stronger selfie camera are priorities — especially if you find a refurbished/renewed model with a healthy battery and Snapdragon 888. 

• Skip both and buy newer if: you want the absolute best camera zoom, bleeding-edge performance, or the latest software for many more years — newer S-series models (S23/S24/S25) will be safer long-term buys.

Practical buying tips

• Confirm chipset before purchase (snapdragon vs exynos) — it affects performance and thermals. Sellers often list the region/SKU code. 

• Check battery health when buying used — a 90%+ health is ideal. The FE’s larger battery is forgiving but capacity degrades with age. 

• Look for certified renewed units that include a warranty. Samsung-certified renewed phones often include a limited warranty and refurbishment checks.

• Verify software patch level — older phones sometimes lag on security patches if sold unlocked from shady sources. Use Settings → Software update to confirm. 

Conclusion — which phone wins in 2025?

There’s no single winner: the S21 FE is the pragmatic all-rounder in 2025 — larger screen, longer battery life, higher-res selfie, and strong value when refurbished. The S21 remains the compact, pocket-friendly flagship for those who prefer a smaller device. Both phones share Samsung’s core display quality, 120Hz smoothness, and competent camera systems; the final choice hinges on size and battery priorities plus the exact chipset in the unit you buy. If you follow the simple checklist above (check SKU, battery health, and software patch level) you’ll end up with a dependable Galaxy that still competes with many midrange 2025 phones — and you’ll save money versus buying a current-generation flagship.