X100 Ultra vs 15 Ultra

Phone 1

Phone 2

Winner

Xiaomi 15 Ultra

Lifespan decides this one: the 15 Ultra is supported until Mar 2030 at $30.38 per month of safe use, while the X100 Ultra runs out in May 2029 ($20.39/month). On a which-lasts-longer question, that's not a tie — it's the whole answer.

Value Score: X100 Ultra 66 · 15 Ultra 65 — methodology

The lifespan decider

When specs are close, support length decides it — this is what each phone costs per month of safe use.

Vivo X100 Ultra $720

Buy with care$20.39/mo

2024◆ Buy-by May 20272029

Xiaomi 15 Ultra $1350

Safe to buy$30.38/mo

2025◆ Buy-by Mar 20282030

Category by category

Display

X100 Ultra 9015 Ultra 100

The 15 Ultra's screen is the better one — 6.73-inch 2k (1440×3200) ltpo amoled, 1–120hz, up to 3200 nits peak.

Performance

X100 Ultra 9215 Ultra 98

The 15 Ultra's Qualcomm Snapdragon 8 Elite (3nm) is simply the faster chip.

Camera

X100 Ultra 8415 Ultra 96

The 15 Ultra has the stronger camera system (4 real rear lenses vs 3).

Battery

X100 Ultra 9015 Ultra 88

Battery capacities are close enough not to decide this.

Software longevity

X100 Ultra 4215 Ultra 53

The 15 Ultra is supported until Mar 2030 — 9 months longer than the X100 Ultra.

Value

X100 Ultra 6615 Ultra 65

Pound for pound, these two are equally good deals.

Full spec table

Spec	X100 Ultra	15 Ultra
Price (street)	$720	$1350
Display	6.78-inch LTPO AMOLED, 120Hz, 3000 nits peak	6.73-inch 2K (1440×3200) LTPO AMOLED, 1–120Hz, up to 3200 nits peak
Chipset	Snapdragon 8 Gen 3	Qualcomm Snapdragon 8 Elite (3nm)
RAM	12GB/16GB	16GB
Storage	256GB/512GB/1TB	512GB/1TB
Battery	5,500 mAh	5,410 mAh
Charging	80W wired, 30W wireless	90W wired, 80W wireless
Rear cameras	50MP main, 200MP periscope telephoto, 50MP ultra-wide	50MP main, 50MP ultra-wide, 50MP telephoto (70mm floating), 200MP periscope telephoto
Dimensions	164.1 x 75.6 x 9.2 mm	161.3 × 75.3 × 9.35 mm
Weight	229 g	226 g
Water resistance	IP68/IP69	IP68
Supported until	May 2029	Mar 2030

X100 Ultra full verdict →15 Ultra full verdict →Longevity master board →

Scores and verdicts are computed from our verified database — see exactly how. Specs from manufacturer documentation; prices reflect major US retailers.