- Install a baby monitor app such as Mamoon on the old phone (iPhone XS or newer with iOS 17, or Android 8+) and on your own phone.
- Put the old phone on a crib arm or in a stand 3–5 feet (1–1.5 m) from the crib, aim it at the mattress, and keep it on the charger.
- Run the charging cable away from the crib, out of the baby's reach.
- Phones can't see in total darkness: leave a dim night light on, or use a Wi-Fi camera with night vision.
- No SIM card or internet needed, only your home Wi-Fi.
What you need
- An old phone: iPhone XS, XR or newer with iOS 17, or Android 8 and up. No SIM card needed. A cracked screen is fine if the camera and microphone work.
- A charger and a long cable, so the phone can stay plugged in all night.
- A stand or mount, so it sits steady and looks at the crib from above or the side.
- Home Wi-Fi. The internet doesn't have to work; the phones talk through your router. Two iPhones running Mamoon can even connect without a router. Any mix of iPhone and Android works: two phones as a baby monitor.
- Your own phone as the parent screen.
Step by step
- Install the app on both phones. In Mamoon on the old phone, choose "Be with the baby".
- Pair them. Scan the QR code on the old phone with yours, or type the six-digit code. No account, no e-mail.
- Place the phone by the crib, on a crib arm or a stand about 3–5 feet away, higher than the mattress so the whole sleep area is in view. You'll see a preview on the screen straight away.
- Plug in the charger. Mamoon shows how long the battery will last, but for the night the charger is the safe bet.
- Choose when it should wake you: only crying, crying and fussing, or every sound. Then you can mute the nursery sound in Mamoon and sleep; a cry still alerts you. Keep your own phone's ringer on (a silenced phone shows the alert without a sound), or allow Mamoon in Sleep or Do Not Disturb: how alerts reach a locked phone.
Where to put the phone
A flexible arm clipped to the crib gives the best view, right above the mattress; a shelf or dresser next to the crib or a wall mount works too. Aim the camera down at the mattress at an angle, like a ceiling camera, so you still see the whole baby after they roll over. The phone itself stays outside the crib, not on the mattress.
Seeing at night
Phones have no infrared light, so in complete darkness you'll see only noise. Very little light is enough, though: a dim night light or a door left ajar. Mamoon brightens the picture in low light by itself. For a sharp picture in total darkness, use a cheap Wi-Fi camera with night vision instead; Mamoon works with both.
Sound and cry detection work just as well in the dark.
Battery and heat
- Keep the phone on the charger. An older battery lasts only a few hours of watching.
- Take the case off so the phone stays cooler.
- Silence notification sounds on the old phone so nothing wakes you or the baby.
- It's fine if the old phone's screen goes dark: Mamoon keeps watching.
Old phone or a dedicated monitor?
| Item | Old phone with Mamoon | Dedicated video monitor |
|---|---|---|
| Price | $0 for the camera; $29.99 once, for life, or $3.99 a month with 14 days free | roughly $50–400 |
| Parent screen | your phone | another display to charge |
| Cry detection | yes, tells a cry from other sounds | usually sound level only |
| Night vision | with a dim light only (or use a Wi-Fi camera) | yes, infrared |
| Range | your whole home Wi-Fi | radio range, typically a few hundred feet |
In detail: Mamoon vs Philips Avent, the best video baby monitor.
Frequently asked questions
Does the old phone need a SIM card?
No. It only has to join your home Wi-Fi. No SIM card or mobile data needed.
Do I need the internet?
No. The phones connect over your home Wi-Fi even when the internet is down. The video never goes through a server.
How old can the phone be?
For Mamoon: an iPhone XS, XR or newer with iOS 17, or Android 8 and up.
Can I see the baby at night?
In low light yes; in complete darkness a phone can't see because it has no infrared light. For a dark room a Wi-Fi camera with night vision is better. You'll always hear a cry, and Mamoon alerts you to it.
What if the Wi-Fi drops or the phone dies?
Mamoon notices, turns the screen gray and alerts you within 20 seconds. It never shows "Calm" when it can't hear.
Can the old phone go on the crib?
Yes, on a flexible arm clipped firmly to the outside of the crib; that gives the best view. Keep the phone itself out of the crib, and run the charging cable away, out of the baby's reach.
Sources
Spotted a mistake or an outdated figure? Write to [email protected].
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.
