Turn an Old Phone Into a Baby Monitor: What Works and What Doesn't

That old phone in the kitchen drawer can do a good job as a baby monitor. It has a microphone, a camera and Wi-Fi, and it no longer needs to last all day on battery. But not every old phone is suitable.

Start with the battery

If the battery is swollen, don't use the phone. A back panel that bulges, a screen lifting from the frame or a phone that no longer sits flat are all warning signs. A phone that spends every night plugged in beside a sleeping baby shouldn't have a damaged battery.

A battery that's merely worn out is fine, because the phone will stay on the charger anyway. Still, use its original charger or a reputable replacement, and leave space around the phone so heat can escape. Don't cover it or tuck it behind soft furnishings.

Check the software

The phone needs a browser recent enough to keep the screen awake, which is what stops the microphone from cutting out.

iPhone: Screen Wake Lock arrived in Safari with iOS 16.4. A long-running bug stopped it from working in apps added to the Home Screen, and reports say that was only fixed in iOS 18.4. If your old iPhone is on something older, you can turn off Auto-Lock in Settings instead.

Android: Install the current version of Chrome if the phone still accepts updates. If it can't update Chrome, look for another device.

Test the hardware

Before you do anything else, record a short voice memo and a video on the phone, then play them back on the device.

• Is the microphone clear from across a room? Cheap or damaged microphones are the most common reason an old phone disappoints.
• Does the camera work? A phone without a working camera is still fine as an audio-only monitor.
• Does the phone hold a Wi-Fi connection reliably from the nursery?

Keep your expectations realistic for video at night. Phone cameras aren't built for dark rooms, and most have no infrared night vision. In a very dark nursery, the picture will be dark too. Audio and cry alerts still work.

What you give up on an old iPhone

• Battery level: iPhones don't report their battery level to websites, so you won't see it remotely. Keep the phone plugged in.
• Background running: Bug reports describe the microphone stopping when a web app is minimized on iOS. Leave the app open and on screen.

Prepare the phone

1. Sign out of personal accounts and remove photos and messages you wouldn't want on a device left running around the house.
2. Set a passcode, and install any available software updates.
3. Silence it. Turn off ringtones and notification sounds so a late-night alert doesn't wake your baby.
4. Turn off battery saver. Power-saving modes can stop apps that seem idle.

Where it goes

Keep the phone and its cable at least three feet from the crib, out of reach. See our placement guide before you pick a spot.

Once it's ready, follow the two-phone setup guide and run the tests at the end before you depend on it.