Samsung Galaxy S21 FE 5G vs Samsung Galaxy S25 Ultra
Our Verdict: There's four years between the Galaxy S21 FE 5G and the Galaxy S25 Ultra, so the Galaxy S25 Ultra is ahead on most things. The S25 Ultra leads on camera hardware with a 200MP main sensor to the S21 FE 5G's 12MP, and the S25 Ultra packs the bigger battery, 5000mAh against 4500mAh, which usually means longer between charges. The S25 Ultra has the stronger screen, bigger at 6.8" against 6.4" and sharper at 505 PPI, and the S25 Ultra offers up to 1TB of storage versus 256GB on the S21 FE 5G. If you're on the S21 FE 5G, the S25 Ultra is a real step up, but only worth it if the changes above matter to you.
If you'd rather pay up front, the S21 FE 5G is the cheaper buy at £130 SIM-free.
10 reviews 4.4
12 reviews
Prices updated 25 July 2026
Samsung Galaxy S21 FE 5G
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Samsung Galaxy S25 Ultra
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|---|---|---|
| Expert Rating | 3.9 10 reviews |
4.4 12 reviews |
| Screen | 6.4" | 6.8" |
| Display | Dynamic AMOLED 2X capacitive touchscreen | Dynamic LTPO AMOLED 2X |
| Resolution | 1080 x 2400 | 1440 x 3120 |
| Pixels Per Inch | 411 | 505 |
| Rear Camera | 12 Megapixels | 200 Megapixels |
| Front Camera | 32 Megapixels | 12 Megapixels |
| Chipset | Exynos 990 | Qualcomm SM8750-AB Snapdragon 8 Elite (3 nm) |
| Battery | 4,500 mAh | 5,000 mAh |
| Storage | 128GB, 256GB | 256GB, 512GB, 1TB |
| OS | Android 12 | Android 15 |
| SIM Type | Nano SIM | nano-SIM and e-SIM |
| Connectivity | Up to 5G | Up to 5G |
| Wi-Fi | 802.11 a/b/g/n/ac/6 | 802.11 a/b/g/n/ac/6e/7 |
| Bluetooth | 5.0 with A2DP, LE | 5.3, A2DP, LE |
| Dimensions | 159.8 x 74.5 x 8.4 mm | 162.8 x 77.6 x 8.2 mm |
| Weight | 177 grams | 219 grams |
| Water Resistance | IP68 - Dust and water resistant over 1.5 meter and 30 minutes | IP68 - Dust and water resistant over 1.5 meter and 30 minutes |
| Contracts | - |
£33.79/mo
£29.00 upfront |
| SIM-free | £129.99 | £569.99 |
| Prices updated 25 July 2026 | ||
| Deals | Deals | |
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Frequently Asked Questions
Which has the better screen, the Samsung Galaxy S21 FE 5G or Samsung Galaxy S25 Ultra?
The Samsung Galaxy S25 Ultra has the bigger screen at 6.8" compared to the Samsung Galaxy S21 FE 5G's 6.4", the Samsung Galaxy S25 Ultra has the sharper display at 505 pixels per inch versus 411, and the Samsung Galaxy S21 FE 5G uses a Dynamic AMOLED 2X capacitive touchscreen panel while the Samsung Galaxy S25 Ultra has a Dynamic LTPO AMOLED 2X.
Which has the better camera, the Samsung Galaxy S21 FE 5G or Samsung Galaxy S25 Ultra?
The Samsung Galaxy S21 FE 5G features a 12 Megapixels rear camera, while the Samsung Galaxy S25 Ultra has a 200 Megapixels rear camera. Both devices also have front-facing cameras for selfies and video calls.
Which is cheaper to buy SIM-free, the Samsung Galaxy S21 FE 5G or Samsung Galaxy S25 Ultra?
The Samsung Galaxy S21 FE 5G is cheaper SIM-free, starting from £129.99.
What storage options are available for the Samsung Galaxy S21 FE 5G and Samsung Galaxy S25 Ultra?
The Samsung Galaxy S21 FE 5G is available in 128GB, 256GB, while the Samsung Galaxy S25 Ultra comes in 256GB, 512GB, 1TB.
What processors do the Samsung Galaxy S21 FE 5G and Samsung Galaxy S25 Ultra use?
The Samsung Galaxy S21 FE 5G is powered by the Exynos 990, while the Samsung Galaxy S25 Ultra uses the Qualcomm SM8750-AB Snapdragon 8 Elite (3 nm).
Which is easier to carry and hold, the Samsung Galaxy S21 FE 5G or Samsung Galaxy S25 Ultra?
The Samsung Galaxy S21 FE 5G is the more portable of the two: it's 42g lighter at 177 grams, it's also the more compact phone at 159.8 x 74.5 x 8.4 mm.
Which is more water resistant, the Samsung Galaxy S21 FE 5G or Samsung Galaxy S25 Ultra?
Both phones share the same water resistance rating of IP68 - Dust and water resistant over 1.5 meter and 30 minutes.
What operating system do the Samsung Galaxy S21 FE 5G and Samsung Galaxy S25 Ultra run?
The Samsung Galaxy S21 FE 5G runs Android 12 and the Samsung Galaxy S25 Ultra runs Android 15. This is one of the biggest factors when choosing between the two, as each ecosystem has its own apps, services and features.