Galaxy S21 Ultra vs S25 Ultra: 4-Year Upgrade Worth Making
If you bought a Galaxy S21 Ultra in 2021, you're well overdue for an upgrade in 2026. S25 Ultra was runner-up Phone of the Year at MKBHD's 2025 Smartphone Awards — and the 4-year gap is enormous.
Updated · Verdict based on MKBHD Smartphone Awards results and spec analysis.
Samsung Galaxy S21 Ultra
Samsung · 2021 · From $1199
Samsung Galaxy S25 Ultra
Samsung · 2025 · From $1299
Round wins
Samsung Galaxy S21 Ultra: 0 · Samsung Galaxy S25 Ultra: 7
Specs side-by-side
| Spec | Samsung Galaxy S21 Ultra | Samsung Galaxy S25 Ultra |
|---|---|---|
| Display | 6.8-inch QHD+ AMOLED, 120Hz LTPO | 6.9-inch QHD+ AMOLED, 120Hz LTPO |
| Processor | Snapdragon 888 | Snapdragon 8 Elite |
| RAM | 12GB | 12GB |
| Camera | 108MP main + 12MP ultrawide + 10MP 3x + 10MP 10x telephoto | 200MP main + 50MP ultrawide + 10MP 3x + 50MP 5x telephoto |
| Battery | 5,000 mAh | 5,000 mAh |
| OS | Android 11 (One UI 3.1) | Android 15 (One UI 7) |
| Starting price | $1199 | $1299 |
| Released | 2021 | 2025 |
Round-by-round breakdown
Display
Winner: Samsung Galaxy S25 UltraS25 Ultra: 6.9-inch with anti-reflective coating, ~2,600 nits typical. S21 Ultra: 6.8-inch at ~1,500 nits. Material brightness improvement.
Performance
Winner: Samsung Galaxy S25 UltraSnapdragon 8 Elite is roughly 100% faster than Snapdragon 888 with dramatically better thermals.
Camera
Winner: Samsung Galaxy S25 UltraSame 200MP main hardware (S22 onward) but processing is generations ahead. S21 Ultra had 108MP main and lower-res telephoto.
S Pen
Winner: Samsung Galaxy S25 UltraS25 Ultra has integrated S Pen housing. S21 Ultra supported S Pen but housing was sold separately. Material convenience improvement.
Galaxy AI
Winner: Samsung Galaxy S25 UltraS25 Ultra has the full Galaxy AI suite. S21 Ultra has none.
Battery
Winner: Samsung Galaxy S25 UltraS25 Ultra: 8+ hours screen-on. S21 Ultra on 4+ year old battery: 3–4 hours typical. Transformative.
Software longevity
Winner: Samsung Galaxy S25 UltraS25 Ultra: 7 more years. S21 Ultra: end of major updates; security only through early 2026.
Final verdict
Yes, upgrade — urgently. S21 Ultra is at the end of its software support window, battery is severely degraded, and Snapdragon 888 thermals are notorious. The S25 Ultra adds Galaxy AI, integrated S Pen, 7-year update commitment, and dramatically better cameras and battery.
Frequently Asked Questions
Should I upgrade from Galaxy S21 Ultra to S25 Ultra?
Yes — urgently. The S21 Ultra is at end-of-life (security patches only through early 2026), and the S25 Ultra is a transformative upgrade across every spec.
Cheaper Galaxy upgrade options from S21 Ultra?
Discounted S24 Ultra at $899–$999 — won MKBHD's 2024 Phone of the Year, 7-year update commitment, and significantly better than S21 Ultra at much lower cost than the S25 Ultra.
How long is the Galaxy S21 Ultra still supported?
Major updates ended in 2024; security patches end in early 2026. Effectively at end-of-life from mid-2026.