Samsung Galaxy S21 Ultra vs Samsung Galaxy S25 FE
Our Verdict: The Galaxy S25 FE is four years newer than the Galaxy S21 Ultra, and it shows in the specs. The S21 Ultra 5G leads on camera hardware with a 108MP main sensor to the S25 FE's 50MP, plus a 40MP selfie camera against 12MP, and the S21 Ultra 5G has the sharper display at 516 PPI to 385. The S25 FE is the lighter phone at 190g against 228g. If you're on the S21 Ultra 5G, the S25 FE is a real step up, but only worth it if the changes above matter to you.
Buying outright, the S21 Ultra 5G starts at £210 SIM-free.
10 reviews 4.0
10 reviews
Prices updated 25 July 2026
Samsung Galaxy S21 Ultra
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Samsung Galaxy S25 FE
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|---|---|---|
| Expert Rating | 4.4 10 reviews |
4.0 10 reviews |
| Screen | 6.8" | 6.7" |
| Display | Dynamic AMOLED 2X capacitive touchscreen | Dynamic LTPO AMOLED 2X |
| Resolution | 1440 x 3200 | 1080 x 2340 |
| Pixels Per Inch | 516 | 385 |
| Rear Camera | 108 Megapixels | 50 Megapixels |
| Front Camera | 40 Megapixels | 12 Megapixels |
| Chipset | Exynos 2100 | Exynos 2400 (4 nm) |
| Battery | 5,000 mAh | 4,900 mAh |
| Storage | 128GB, 256GB, 512GB | 128GB, 256GB, 512GB |
| OS | Android 11 | Android 16 |
| 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 |
| Bluetooth | 5.1 with A2DP, LE | 5.4, A2DP, LE |
| Dimensions | 165.1 x 75.6 x 8.9 mm | 161.3 x 76.6 x 7.4 mm |
| Weight | 228 grams | 190 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 | - |
£23.54/mo
£9.00 upfront |
| SIM-free | £209.99 | £399.99 |
| Prices updated 25 July 2026 | ||
| Deals | Deals | |
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Frequently Asked Questions
Which has the better screen, the Samsung Galaxy S21 Ultra or Samsung Galaxy S25 FE?
Both phones have a similar screen size at around 6.8", the Samsung Galaxy S21 Ultra has the sharper display at 516 pixels per inch versus 385, and the Samsung Galaxy S21 Ultra uses a Dynamic AMOLED 2X capacitive touchscreen panel while the Samsung Galaxy S25 FE has a Dynamic LTPO AMOLED 2X.
Which has the better camera, the Samsung Galaxy S21 Ultra or Samsung Galaxy S25 FE?
The Samsung Galaxy S21 Ultra features a 108 Megapixels rear camera, while the Samsung Galaxy S25 FE has a 50 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 Ultra or Samsung Galaxy S25 FE?
The Samsung Galaxy S21 Ultra is cheaper SIM-free, starting from £209.99.
What storage options are available for the Samsung Galaxy S21 Ultra and Samsung Galaxy S25 FE?
The Samsung Galaxy S21 Ultra is available in 128GB, 256GB, 512GB, while the Samsung Galaxy S25 FE comes in 128GB, 256GB, 512GB.
What processors do the Samsung Galaxy S21 Ultra and Samsung Galaxy S25 FE use?
The Samsung Galaxy S21 Ultra is powered by the Exynos 2100, while the Samsung Galaxy S25 FE uses the Exynos 2400 (4 nm).
Which is easier to carry and hold, the Samsung Galaxy S21 Ultra or Samsung Galaxy S25 FE?
The Samsung Galaxy S25 FE is the more portable of the two: it's 38g lighter at 190 grams, it's also the more compact phone at 161.3 x 76.6 x 7.4 mm, and is slimmer at 7.4mm thick.
Which is more water resistant, the Samsung Galaxy S21 Ultra or Samsung Galaxy S25 FE?
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 Ultra and Samsung Galaxy S25 FE run?
The Samsung Galaxy S21 Ultra runs Android 11 and the Samsung Galaxy S25 FE runs Android 16. This is one of the biggest factors when choosing between the two, as each ecosystem has its own apps, services and features.