If you own an Amazfit T-Rex 3 or a T-Rex Ultra 2 smartwatch, good news is heading your way. Amazfit is pushing out a brand-new software update, version 6.4.16.3.
While big updates often sound complicated, this one is all about making your daily workouts and health tracking smoother and much more reliable.
Better Workouts and Swimming Stats

Fitness tracking is a huge part of why people wear rugged smartwatches like these, and this update brings some very welcome fixes:
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Quicker Wake-Up: The watch now does a better job waking up when you lift your wrist during a tough workout, meaning you won’t have to shake your arm to check your stats.
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Pool Swimming Upgrades: If you love swimming laps, you will notice cleaner, easier-to-read pace and stroke-rate charts. Plus, the watch is now much sharper at counting your turns accurately.
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Pickleball and Strength Training: Pickleball players now get swing count tracking. If you lift weights, you can finally turn the “Auto Grouping” feature on or off depending on how you like your sets recorded.
Smarter Health and Navigation
Beyond the gym, Amazfit has polished everyday features that make the watch more personal and easier to use:
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Upgraded Cycle Tracking: The period tracking app got a complete visual makeover. It brings better period predictions along with brand-new check-in options to log your daily symptoms, moods, and lifestyle habits.
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Waypoints and Recovery: Outdoor explorers get support for more waypoint icons and types. Once your workout wraps up, the post-workout RPE (Rate of Perceived Exertion) screen has been redesigned to make logging how hard you worked a breeze.
When Can You Get It?
Right now, the update is rolling out in phases. That means some users are already seeing it pop up on their phones, while others might need to wait a few days for it to land on their devices. Keep an eye on your Zepp app!
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