How much data does a baby monitor use?

Last updated: 2026-09-02

It depends on two settings and on how much of the night is actually noisy. Most apps will not tell you, so here are HushCam's real numbers, measured on the wire between an iPhone transmitter and a receiver in every mode the app offers.

The two settings that decide it

HushCam has a camera switch and an activation switch. Together they give four combinations.

Data per hour of active streaming

Four things those numbers hide

• The cap is a ceiling, and a quiet room stays under it. The encoder cap is the most the app will ever ask for. Audio stays below it because the codec sends almost nothing in silence, and a still nursery compresses well; a noisy room with a moving child pushes the measured figures up toward the cap.
• Packet overhead matters most for audio. Audio goes out in 50 small packets per second, so headers are a large share of a small stream. That is why low and standard audio measure closer together than their bitrates suggest, while for video the same overhead is a few percent.
• A quiet night in the default mode is nearly free. In sound-activated mode with nothing to hear, the link idles at about 4 MB per hour: heartbeats, keep-alives and the codec's silence frames. That is the floor a night starts from.
• How these were measured. At the receiver, from WebRTC's own transport counters, over three minute windows, with an iPhone as the transmitter on a direct connection. They exclude the IP and UDP headers, roughly another 5 percent, and your own figure will vary with your network and how lively the room is.

What a night actually costs

Take a ten hour night with roughly twenty minutes of noise in it, which is a fairly ordinary night with a sleeping baby.

• Default mode, camera on and sound-activated: about 100 MB, twenty minutes of streaming plus the idle floor for the rest of the night.
• Same night with the camera always on at the default presets: about 1.8 GB, because all ten hours stream. At the standard presets it is about 5.7 GB.
• Audio only, always on: about 100 MB for the whole night at the default preset, about 130 MB at standard.
• Audio only, sound-activated: about 45 MB, almost all of it the idle floor.

On the same Wi-Fi, it costs nothing

This is the part most comparisons miss. When both devices are on the same network, the audio and video travel directly between them and never leave your home at all. None of it counts against an internet allowance, because none of it touches the internet. Only the tiny setup handshake does.

The numbers above matter when one device is somewhere else and streaming over mobile data. They also apply on the rare connections where the two devices cannot reach each other directly and our relay has to forward the encrypted packets.

How to use less

• Keep the default sound-activated mode. It is the single biggest saving, and it gates audio as well as video.
• Use audio only when you do not need to see the room. At the default presets it is more than fifteen times cheaper than video, and the gap grows with video quality.
• Drop the video quality preset if you have raised it. Low is 360p, it is the default, and it is still perfectly legible for checking on a sleeping child.
• Keep both devices on the same Wi-Fi when you can, and the question stops applying.
• Check the live data counter in the app's settings. It reports the current session and the lifetime total.