You're watching a video or in the middle of a game and a notification slides in over the top, blocking what you're doing. Those are heads-up (or "peeking") notifications. You can kill the interruptions without muting the app completely — so you still get the alert, just quietly in the shade.
What these pop-ups are
Heads-up notifications are the floating banners Android shows for high-priority alerts (calls, alarms, sometimes chat pings). They're useful in theory but noisy in practice when every app claims "urgent". The fix is to lower an app's priority so it stops peeking.
Stop one app's pop-ups
- When the pop-up appears, long-press it → tap the gear icon → the channel.
- Set Importance to Low (shows in shade, no sound) or Min (shows silently), or turn off Pop on screen.
- The notification still arrives — it just stops floating over your screen.
Silence all pop-ups
- Do Not Disturb / Focus mode suppresses heads-up pop-ups for everything, with optional exceptions (e.g. allow calls from starred contacts).
- Per-app lowering (above) is the more surgical option if you only want to quiet a few noisy apps.
Why some still pop
- Ongoing notifications (navigation, foreground calls, screen recording) always pop by design.
- Apps with multiple channels — you may have lowered "Messages" but not "Calls" or "Alerts". Check each one.
- A freshly installed update can reset a channel's importance; re-check after big app updates.