Apple Watch Ultra 4 has the same external look as Ultra 3, but it’s packed with internal upgrades to the chip and health sensors that unlock new and improved features. Here’s everything new in Apple Watch Ultra 4 vs Ultra 3.

And last year, Apple opted to stick with the same S10 from 2024. But Apple Watch Ultra 4 has a brand-new S11 chip. Apple often includes a new chip with its latest Watch models, but most chip updates include only minor changes and minimal performance gains. S11 unlocks exclusive new software features thanks to its more powerful capabilities.
Apple doesn’t give specific benchmarks to measure the improvements, only saying S11 is its “most powerful wearable chip.”
Apple Watch Ultra 4 also doubles the memory of Ultra 3, with 4GB versus the 2GB of last year’s model. Apple Watch Ultra 4 has an all-new Health Sensing System that might be the biggest change ever to the Watch’s internal sensors. 15 minutes gets you 18 hours of runtime, versus only 12 on Apple Watch Ultra 3. Here’s what it does per Apple : Apple Watch Ultra 4 introduces readiness, a new feature that analyzes a user’s recent activity, training load, vitals, and sleep score to offer insight into their capacity for the day ahead. Readiness provides a single 0-10 score each day with a clear, actionable recommendation: Recover, Pace Yourself, Ready, or Go For It. Apple Watch Ultra 4 will also support a suite of Audio Intelligence features, some of which are coming in a software update later this year. A double press of the Digital Crown shows the previous 15 seconds of a conversation as a text snippet, so users can catch something they may have missed or are less familiar with. It ships Friday, September 18. Which Apple Watch Ultra 4 features are you most interested in? Let us know in the comments. * Buy Apple Watch with 15% discount from Apple refurbished AirPods Pro 3 ( now only $199 , down from $249) Portable USB-C charger for Apple Watch MagSafe Car Mount for iPhone 10-year AirTag battery case 2-pack Retro Mac stand for Apple Watch Nightstand Mode You’re reading 9to5Mac — experts who break news about Apple and its surrounding ecosystem, day after day.
Readiness is a health feature that’s become common with other wearables, and now Apple has its own version with a Readiness app. This helps a user decide how to take on their day, whether they’re headed into a workday or tackling their training plan. Audio Intelligence includes : Sound Recognition : “[alerts] users who are deaf or hard of hearing of important sounds, even when their iPhone isn’t with them. This feature listens for sounds like sirens, alarms, doorbells, or a baby crying, and uses on-device intelligence to notify users when they’re detected. Siri Recap : [creates] high-level summaries of conversations that users can review later to jog their memory. When Siri Recap is turned on, after a conversation, Apple Intelligence automatically generates a title and key points in the new Siri app, allowing users to be more present and engaged in the moment. Do you plan to upgrade? Be sure to check out our homepage for all the latest news, and follow 9to5Mac on Twitter , Facebook , and LinkedIn to stay in the loop. Don’t know where to start? Check out our exclusive stories , reviews , how-tos , and subscribe to our YouTube channel
Apple says the new system “unlocks deeper health and fitness insights. Here’s the breakdown of feature improvements, per Apple : Heart rate tracking : Second-generation electrical heart sensor and always-on optical heart sensor enable high-frequency background heart rate tracking that you can view on new heart rate watch face complication HRV improvements : “now measured up to 24 times more often and available to view in a new section of the Heart Rate app” Apple Watch Ultra 4 can also provide 50% more battery life on a quick 15-minute charge. Live Rewind : “[helps] users recall what was just said in conversation. Shazam : “instantly detects the music playing around the user and automatically displays the song title and artist’s name on the Music Recognition widget in the Smart Stack” Apple Watch Ultra 4 is now available to pre-order at $799 .


Here’s the comparison: Apple Watch Ultra 4 : up to 50 hours battery life, or 84 hours in Low Power Mode Apple Watch Ultra 3 : up to 42 hours battery life, or 72 hours in Low Power Mode
New Recovery HRV : “best for identifying daily signals of stress and recovery” Step tracking : More accurate, with new Steps complication to track steps in real time from watch face One of Apple Watch Ultra’s best features is battery life, and Ultra 4 delivers noteworthy gains in that department.


