A baby monitor app that works when the phone is locked

Does a baby monitor app keep working when the phone is locked?

Only if the app asks to keep playing sound in the background, and you let it. iPhone stops most apps seconds after the screen locks, but lets apps that play audio carry on. Android lets an app keep running with a permanent notification, and then a battery manager may still stop it. So two apps on the same phone can behave in opposite ways, and the other baby monitor guides assume you've checked yours.

It helps to separate two things. The live sound is the nursery playing from your phone's speaker. The alert is a push notification when the camera hears crying or noise. Alerts go through the maker's cloud and usually arrive on a locked phone. The live sound depends on the app, and here the big brands differ a lot.

From each maker's help pages, checked October 28, 2026; details under Sources. Apps change, so check your app version.

What Nanit, Arlo, Wyze, Tapo and eufy do

Nanit: turn on Background Audio

Nanit's help article says the sound keeps playing with the screen off, once Background Audio is on. In Live, tap the speaker icon until it says Background Audio On. There is also a Background audio switch in the camera's Sound settings. Two catches: another app playing sound takes over, and Nanit asks you to allow mobile data so the sound survives a Wi-Fi drop. The Nanit comparison covers what else needs the cloud.

Arlo: alerts yes, live sound unclear

Arlo has no help page on background audio. Owners in Arlo's forums report it both ways, and picture in picture is still a feature request. What Arlo does document is sound alerts: under Routines, open your mode, pick the camera and turn on Audio Detection. Arlo's knowledge base says the options vary by device and plan.

Wyze: picture in picture, not background audio

Wyze has no background audio, and owners have asked for it for years. On the Cam v4, v3 Pro and a few others, Wyze's picture in picture keeps a small window open while you use other apps. Turn it on in the phone's settings first, then tap the icon in live view each time. Crying alerts need a Cam Plus plan. More in a Wyze Cam as a baby monitor.

Tapo: alerts work, the live view stops

TP-Link documents no background audio or picture in picture. Owners on TP-Link's forum say the live view stops when you leave the app. Baby Crying Detection still sends alerts through TP-Link's cloud. If they come late or not at all, the Tapo crying detection fixes go through it step by step.

eufy: Background Audio in eufy Baby

The eufy Baby app for Android added background audio in version 1.3.0: tap Sound on the live page, and the sound continues in the background. For the iPhone app and for eufy Security cameras, eufy doesn't say, so check your app version. The eufy comparison covers the rest of the monitor.

How to keep the sound on when the phone is locked

These steps work for any monitor app. The system steps are the same for all; the screen below is Mamoon's, as an example.

1. Turn on the app's background sound. Nanit: Background Audio On. eufy Baby: Sound on the live page. In Mamoon there is nothing to turn on: the nursery keeps playing with the screen locked.
2. Allow notifications with sound. If you tapped "Don't allow" at first launch, fix it under Settings → Notifications (iPhone) or Settings → Notifications → App notifications (Android).
3. Android: set battery use to Unrestricted. Settings → Apps → the monitor app → App battery usage → Unrestricted, as Google explains. On Samsung, also take it out of Sleeping apps; on Xiaomi, allow Autostart.
4. iPhone: keep the ringer on. With the silent switch on, notification sounds don't play. Only apps with Apple's Critical Alerts permission break through.
5. Allow the app in your Sleep Focus or Do Not Disturb. iPhone: Settings → Focus → Sleep → Apps → Allow Notifications From. Android: Do Not Disturb → Apps.
6. Mute the room, not the alerts. In Mamoon you can turn the nursery sound off for the night and the cry alerts keep coming.
7. Test on a nap. Lock the phone, leave it face down while the baby naps, and have someone make noise by the crib. Check you heard the sound and got the alert.

Why an alert can still stay silent

• The silent switch. Apple's notification page says notification sounds don't play on a silenced iPhone. The alert still lights up and vibrates. A second parent phone, set up as in two phones as a baby monitor, is a backup with its own ringer.
• A Focus. Sleep Focus and Do Not Disturb hold back every app you haven't allowed. The Time Sensitive toggle alone doesn't help ordinary alerts.
• Scheduled Summary. If the monitor app is in it, its alerts wait until morning.
• A battery manager. On Samsung, Xiaomi, Huawei and OnePlus, extra savers can stop even an app with a permanent notification; Don't kill my app keeps the current menus per brand.
• A dropped connection. An app that stops hearing should say so. In Mamoon the screen turns grey with Offline, and you get an alert. What keeps working when the internet itself is down is in a baby monitor without Wi-Fi.

Where Mamoon fits

Mamoon is built for the locked phone. The live sound keeps playing with the screen off or another app open, on iPhone and Android, with no switch to hunt for. On iPhone the Lock Screen shows it is still listening; on Android, the notification shows the room's state. It recognizes crying on the phone itself, so the alert doesn't wait on a cloud. Its alerts are ordinary notifications, not critical alerts, so a phone on silent shows them without a sound. Sound and cry alerts are free; the picture is $29.99 once or $3.99 a month after 14 days free.

Frequently asked questions

How these pages are made: an AI model drafts them from our own tests, real app screens and the sources listed, and Jan Drábek checks every page before it goes live.