While the iPhone 18 Pro grabs store-shelf headlines, Apple’s new watches start landing on wrists today too. Both the Apple Watch Series 12 ($399) and Ultra 4 ($799) ship September 18 with zero price increase — the headline upgrades are the S11 chip, multi-day-capable battery gains, Siri AI on your wrist, and a new Readiness Score borrowing from the best recovery wearables.
Same design, same prices, better internals. So which one deserves your wrist? Let’s compare.
What’s New in Series 12 and Ultra 4
Both watches run the S11 chip, ship with watchOS 27, and require an iPhone on iOS 27 — update your phone first. Both get Siri AI (conversational, on-wrist, genuinely useful for the first time), a new Readiness Score for sleep and recovery tracking, and 5G cellular standard.
The differences are where it gets interesting:
- Series 12 ($399): battery jumps from ~18 to 24 hours — the first real endurance gain in years. Brighter 2,000-nit display, thinner-feeling 42/46mm case, and new case options including ceramic in Pearl White and Night Blue (though ceramic starts at $899 — more than the Ultra).
- Ultra 4 ($799): a monster 50-hour battery, 3,000-nit display readable in direct sun, 100m water resistance, and titanium-only 49mm case. New chip and sensors, same rugged finishes (Natural, Black).
No blood pressure, no glucose, no Touch ID — the long-rumored health sensors didn’t make it. This is a refinement year, and the battery gains are the story.
Series 12 vs Ultra 4: Head-to-Head
| Series 12 | Ultra 4 | |
|---|---|---|
| Price | $399 | $799 |
| Battery | 24 hours | 50 hours |
| Display | 2,000 nits | 3,000 nits |
| Case | 42/46mm aluminum, titanium, ceramic | 49mm titanium |
| Water resistance | 50m | 100m |
| Weight | ~32–39g | ~63g |
| Best for | Everyday + sleep tracking | Outdoors, diving, multi-day trips |
Buy the Series 12 if you want the best everyday Apple Watch — it’s lighter, cheaper, charges overnight like always, and the 24-hour battery finally covers sleep tracking without anxiety. Pair it with new AirPods 5 and you have Apple’s best-value duo of 2026.
Buy the Ultra 4 if you’re outdoors for days, dive, trail-run ultras, or just hate chargers. Fifty hours means a full weekend off-grid. Everyone else is paying $400 extra for capability they’ll never touch — and wearing a 63g brick to the office.
watchOS 27: What Changes on Your Wrist
The hardware is refinement; the software is the leap. watchOS 27 ships on both watches (and rolls out to older models too) with three upgrades that change daily use. First, Siri AI finally makes the watch a conversational assistant — raise to speak, ask follow-ups, get answers without pulling out your phone. Early reports say it’s the first Siri that feels instant rather than embarrassing.
Second, the Readiness Score pulls sleep, heart-rate variability, and activity into one morning number, borrowing the recovery-tracking playbook from Oura and Whoop — without their subscriptions. Third, deeper iPhone integration: Live Translation sessions started on your phone continue on the watch, and Custom EQ profiles follow your AirPods across devices. One requirement for all of it: your iPhone must be on iOS 27, so run that update before unboxing the watch.
Apple Watch 2026 FAQ
How much is the Apple Watch Series 12? $399 for 42mm aluminum GPS — unchanged from Series 11. Ceramic models run $899–$949.
How much is the Apple Watch Ultra 4? $799, unchanged from Ultra 3. Titanium only, 49mm.
When do the new Apple Watches ship? Both ship September 18, 2026. Pre-orders have been open since September 9.
Do I need iOS 27 for the new watches? Yes — both require an iPhone running iOS 27 or later for pairing and full features including Siri AI.
Series 11 or Ultra 3 owners — upgrade? Series 11 → 12 is worth it for the battery jump alone. Ultra 3 → 4 is marginal unless you want Siri AI and the Readiness Score; your Ultra 3 remains superb.
The bottom line: no price hike, double-digit battery gains, and Siri AI make this the easiest Apple Watch recommendation in years. Most people: Series 12. Adventurers and charger-haters: Ultra 4.
