Two watches, one chip

The Series 12 and Ultra 4 both run Apple's new S11 chip, so their everyday smarts are identical. The split is price, size options, and how far off the grid you plan to go.

Price: $399 vs $799

The Series 12 starts at $399 for a 42mm aluminum GPS model. The Ultra 4 comes one way only: 49mm titanium with cellular, at $799.

The Series 12 can get pricey

Add size and cellular and the titanium Series 12 hits $749. The new ceramic version runs $899 to $949, and the Hermes editions reach $1,399.

Design: pick your flavor

Series 12 comes in aluminum, titanium, or ceramic, two sizes each, in colors from bronze to blue. The Ultra 4 offers one size and two titanium shades.

“If you want some color or have smaller wrists, the Series 12 is the watch to go with.”

Audio Intelligence listens all day

The S11 unlocks a feature that hears your conversations and surroundings, then rewinds the last 15 seconds as text or summarizes a whole talk with key points.

Apple's privacy promise

Apple says a dedicated part of the S11 processes audio locally then deletes it, with no speaker identification and no sensitive data kept. You can switch the whole thing off.

“I'm leery of any always-on AI, but you should be able to just turn it off on either watch.”

A readiness score for training

Both watches give you a zero to 10 energy score with a recommendation for how hard to train. The Health app adds a Longevity tab that estimates your body's Health Age.

Heart rate every five seconds

Redesigned always-on sensors read your heart rate continuously instead of periodically, and capture heart rate variability up to 24 times more often than before.

Satellite messaging is Ultra only

Both share Wi-Fi, Bluetooth 5.3, and 5G. The Ultra 4 adds satellite messages and emergency signals beyond cell coverage, plus dual L1/L5 GPS for sharper positioning.

Only one is dive rated

Both are IP6X. The Series 12 handles 164 feet of submersion but is not for diving. The Ultra 4 survives 328 feet, dives to 141, and carries EN13319 and MIL-STD 810H testing.

Battery: 24 vs 50 hours

Apple claims 50 hours for the Ultra 4 against 24 for the Series 12. Apple usually lowballs: the Series 11 hit 43 hours on a 24-hour claim, the Ultra 3 hit 63 on a 42-hour claim.

Always-on sensors may cost you

With heart rate now sampling constantly, real-world battery on both new models could land closer to Apple's estimates than past generations did.

Who should buy which

Buy the Ultra 4 for multi-day battery, off-grid navigation, or ocean diving. Otherwise the Series 12 has the same brains in a friendlier size at a friendlier price.

“The Series 12 offers all the smarts you actually need in a far more wrist-friendly design.”