The short
- Speed you feel: captions, translate, and quick photo fixes run near-instant when local.
- Battery reality: short bursts are fine; long clips drain unless the chipset throttles wisely.
- Best UX: AI tucked into the camera and keyboard—zero set-up, no extra apps.
- Privacy win: casual tasks stay on your phone; no clips sent to servers.
- Watch for camera-native caption/translate toggles rolling out by default.
Feature matrix: what’s fast, what costs power
| Feature | Offline speed | Battery hit (10-min use) | Where it shines | Notes |
|---|---|---|---|---|
| Live captions (video calls) | Near-instant | Low–Medium | Noisy rooms, weak data | Auto-pause lowers draw |
| Translate (speech ↔ text) | Near-instant | Low | Travel, shop talk | Good with short phrases |
| Camera fixes (denoise, sharpen) | Fast | Low | Low-light photos | Runs on ISP/NPU combo |
| Voice actions (app control) | Fast | Low | Hands-busy tasks | Works offline if cached |
| Summaries (long text/audio) | Okay | Medium | Lec notes, docs | Chunking helps heat |
Tip If a task lasts >10 minutes, look for an “efficiency” toggle—some phones shift to lighter local models to save power.
What real users notice first
Fewer spins, fewer fails
Local runs skip network hiccups. Captions don’t freeze when Wi-Fi drops, and the camera doesn’t hang waiting for the cloud.
Quiet privacy win
Short voice notes and quick edits stay on device. You see results without sending anything off your phone.
Feels built-in
The best rollouts put AI inside the default camera and keyboard. If you don’t need a tutorial, the design is working.
How phones keep heat under control
- Use the NPU for bursty tasks and drop to CPU/GPU when idle.
- Reduce frame rate for captions during long sessions to save power.
- Pause heavy effects when the device gets hot, then resume at a lighter setting.
What to watch next
- Camera-native caption/translate toggle on more phones.
- Battery-saver profiles that auto-switch AI load during long clips.
- “No cloud” badges for basic features—simple trust signal for users.