Apple unveils Watch Series 12 and Ultra 4 with S11 chip and 15-second audio rewind

Hardware architecture and S11 processor

Apple unveiled the Apple Watch Series 12 and Apple Watch Ultra 4 during its keynote event titled 'Surprise and shine', presented by John Ternus alongside the iPhone Duo, iPhone 18 Pro, and AirPods 5. Both watch models integrate the S11 System in Package processor, designed to handle expanded on-device artificial intelligence computations and faster sensor management. The Series 12 keeps the 42 mm and 46 mm casing dimensions while equipping aluminium editions with Ceramic Shield 2 front glass, measured to be 60% more resistant than the prior Ion-X glass. The Ultra 4 retains its 49 mm titanium chassis, 3,000-nit LTPO 3 OLED display, 100-meter water resistance, and 40-meter recreational dive rating, offering up to 45 hours of battery life.

Audio Intelligence and conversation transcription

A central focus of the S11 platform is the Audio Intelligence suite, which includes two ambient audio tools named Live Rewind and Siri Recap. Live Rewind continuously buffers 15 seconds of audio in isolated memory; double-pressing the digital crown generates an instant text transcript on the display. The system emits a mandatory audio tone, displays a full-screen graphic, and activates a microphone indicator during transcription to alert nearby individuals. Siri Recap operates in the background to summarize conversations rather than storing verbatim transcripts, processing data via Apple Intelligence and Private Cloud Compute with end-to-end encryption when synchronized to iCloud.

Siri Recap ambiently takes notes on your conversations throughout your day and creates high-level Apple Intelligence-generated summaries that you can use later to jog your memory, so you can stay present in the moment.

Health tracking and daily readiness metrics

Both watches carry re-engineered optical and electrical cardiac sensors with larger green LEDs, enabling continuous heart rate measurements every five seconds, which is 60 times more frequent than previous models. Heart rate variability tracking is sampled up to 24 times more often, dividing data into general HRV and recovery HRV to track daily cardiovascular stress. The Ultra 4 introduces Disposición, a daily readiness metric that evaluates recent exercise strain, nocturnal vitals, and sleep quality on a scale from 0 to 10. The score issues four distinct recommendations (recover, take it easy, prepare, or go all out) based on algorithms developed from Apple health studies involving more than 1,000 participants.

Retail availability, European rollout, and pricing tiers

The Apple Watch Series 12 and Ultra 4 launch in stores on September 18, 2026, following pre-orders opened on September 10. In Spain, the Series 12 starts at 449 euros for the 42 mm aluminium GPS version and 499 euros for 46 mm GPS, with cellular configurations costing 569 euros and 619 euros. Titanium Series 12 models start at 799 euros for 42 mm and 849 euros for 46 mm, while ceramic editions begin at 1,049 euros. The Ultra 4 sells for 899 euros with Alpine Loop, Trail Loop, or Ocean bands, and 999 euros with the titanium Milanese Loop. Audio Intelligence features arrive in English beta in late 2026 and will remain unavailable in the European Union during initial rollout.