Samsung Galaxy S21 Ultra vs Samsung Galaxy S24
Our Verdict: The Galaxy S21 Ultra and the Galaxy S24 are three years apart, which is enough for a real difference. The S21 Ultra 5G has a considerably higher-resolution main camera, 108MP against the S24's 50MP, plus a 40MP selfie camera against 12MP, and there's more battery in the S21 Ultra 5G, 5000mAh to 4000mAh, which should mean longer between charges in day-to-day use. The S21 Ultra 5G has the stronger screen, bigger at 6.8" against 6.2" and sharper at 516 PPI, and the S21 Ultra 5G offers up to 512GB of storage versus 256GB on the S24. Coming from the S21 Ultra 5G, the S24 is a genuine upgrade rather than a token one.
Buying outright, the S21 Ultra 5G starts at £235 SIM-free.
10 reviews 4.2
10 reviews
Prices updated 28 July 2026
Samsung Galaxy S21 Ultra
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Samsung Galaxy S24
|
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|---|---|---|
| Expert Rating | 4.4 10 reviews |
4.2 10 reviews |
| Screen | 6.8" | 6.2" |
| Display | Dynamic AMOLED 2X capacitive touchscreen | Dynamic LTPO AMOLED 2X |
| Resolution | 1440 x 3200 | 1080 x 2340 |
| Pixels Per Inch | 516 | 416 |
| Rear Camera | 108 Megapixels | 50 Megapixels |
| Front Camera | 40 Megapixels | 12 Megapixels |
| Chipset | Exynos 2100 | Qualcomm SM8650-AB Snapdragon 8 Gen 3 (4 nm) |
| Battery | 5,000 mAh | 4,000 mAh |
| Storage | 128GB, 256GB, 512GB | 128GB, 256GB |
| OS | Android 11 | Android 14 |
| SIM Type | Nano SIM | Nano 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 | 5.3, A2DP, LE |
| Dimensions | 165.1 x 75.6 x 8.9 mm | 147.0 x 70.6 x 7.6 mm |
| Weight | 228 grams | 167 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 | - |
£20.00/mo
£49.00 upfront |
| SIM-free | £234.99 | £279.00 |
| Prices updated 28 July 2026 | ||
| Deals | Deals | |
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Frequently Asked Questions
Which has the better screen, the Samsung Galaxy S21 Ultra or Samsung Galaxy S24?
The Samsung Galaxy S21 Ultra has the bigger screen at 6.8" compared to the Samsung Galaxy S24's 6.2", the Samsung Galaxy S21 Ultra has the sharper display at 516 pixels per inch versus 416, and the Samsung Galaxy S21 Ultra uses a Dynamic AMOLED 2X capacitive touchscreen panel while the Samsung Galaxy S24 has a Dynamic LTPO AMOLED 2X.
Which has the better camera, the Samsung Galaxy S21 Ultra or Samsung Galaxy S24?
The Samsung Galaxy S21 Ultra features a 108 Megapixels rear camera, while the Samsung Galaxy S24 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 S24?
The Samsung Galaxy S21 Ultra is cheaper SIM-free, starting from £234.99.
What storage options are available for the Samsung Galaxy S21 Ultra and Samsung Galaxy S24?
The Samsung Galaxy S21 Ultra is available in 128GB, 256GB, 512GB, while the Samsung Galaxy S24 comes in 128GB, 256GB.
What processors do the Samsung Galaxy S21 Ultra and Samsung Galaxy S24 use?
The Samsung Galaxy S21 Ultra is powered by the Exynos 2100, while the Samsung Galaxy S24 uses the Qualcomm SM8650-AB Snapdragon 8 Gen 3 (4 nm).
Which is easier to carry and hold, the Samsung Galaxy S21 Ultra or Samsung Galaxy S24?
The Samsung Galaxy S24 is the more portable of the two: it's 61g lighter at 167 grams, it's also the more compact phone at 147.0 x 70.6 x 7.6 mm, and is slimmer at 7.6mm thick.
Which is more water resistant, the Samsung Galaxy S21 Ultra or Samsung Galaxy S24?
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 S24 run?
The Samsung Galaxy S21 Ultra runs Android 11 and the Samsung Galaxy S24 runs Android 14. This is one of the biggest factors when choosing between the two, as each ecosystem has its own apps, services and features.