Why is “Hey Google” not working on Gemini after the December 2025 update (and how do you fix hands‑free voice activation)?

Is “OK Google” broken on Gemini on Android after the 2025 update? Here’s the quickest hands‑free fix.

After the December 2025 update, many users report that the wake words “Hey Google” and “OK Google” stop triggering Gemini hands-free. In some cases, users see an error that says: “Trouble connecting. Check your connection and try again.”

Another common symptom is that the Assistant hands-free toggle looks disabled or greyed out. Manual launch still works (power button, app icon, or mic button), but wake-word detection fails.

Primary fix: re-enable Gemini hands-free in the Google app

This is the most direct path because wake-word settings for Gemini live inside the Google app.

1. Open the Google app.
2. Tap the profile icon (top right).
3. Tap Settings.
4. Open Gemini.
5. Tap Talk to Gemini hands-free.
6. Turn on the toggle for Hey Google.
7. If prompted, complete the voice training.
8. Confirm the Hey Google toggle remains enabled after training.

Don’t skip this validation step (it matters)

These next actions look repetitive, but they often “finalize” wake-word detection after the toggle is restored.

1. Open Gemini.
2. Tap the microphone and ask a short question (any prompt).
3. Then say “Hey Google” again to confirm wake-word pickup.

If wake words respond now, switching back to Google Assistant (if that option appears on your device) typically works without breaking hands-free again.

If the toggle is on but wake words still fail

Use the checks below in this order. Each one targets a common blocker for wake-word detection.

• Update components: Update the Google app, Gemini (if listed separately), and Google Play services, then reboot the phone.
• Confirm permissions: Ensure the Google app (and Gemini, if applicable) has Microphone permission allowed.
• Check language settings: Set Google app language and Assistant/Gemini language to a supported match (mismatched languages can block voice features).
• Disable battery restrictions: Remove battery optimization for the Google app so it can listen in the background (device wording varies by brand).
• Clear Google app cache: Settings → Apps → Google → Storage → Clear cache (avoid “Clear data” unless needed, since it resets app state).
• Re-run Voice Match (if available): If your device still shows Voice Match settings, retrain and re-test wake words.

Known status and expectation-setting

Google has acknowledged similar hands-free and wake-word regressions during assistant transitions in the past. If this issue is tied to the December 2025 rollout, a server-side or app update may be required for a permanent fix, so the steps above function as practical workarounds until the underlying patch ships.