How to time wifi baby monitor delay in seconds

What are you actually timing?

Delay (latency) is the time between a real sound or movement in the nursery and the moment it appears on the screen you are holding. Parents notice it when they walk out of the room and still see themselves on the phone. The number is not printed on most UK boxes. Which? tests picture quality, range and security on smart monitors; it does not publish a standard lag-in-seconds score on the buying-guide page checked in July 2026.

Two paths give two different clocks. A dedicated parent unit that uses its own radio (or a local Wi-Fi link that never leaves the house) has fewer hops. An app feed that goes camera → router → maker's servers → your phone adds encoding, buffering and the internet path. Hybrid sets can show both: the handheld in under a second, the app several seconds later. Time each path. Do not average them.

Review pages quote wide ranges. Those figures are not your house. The clap test below is the measurement. Write down the seconds you see at bedtime on your router, then again on mobile data if you use remote viewing.

How do I run a clap test in seconds?

You need the camera in its usual place, one other adult or a phone on a stand in the nursery, and a stopwatch app on the device that shows the live feed. Do not time from memory — start and stop on the same clap.

1. 1
   Put the camera where it will sleep Same shelf, same night-vision mode, same Wi-Fi band the set uses at 7pm. A test on the kitchen table will not match a first-floor nursery through two walls.
2. 2
   Open only the feed you are measuring For the handheld: wake the parent unit and stay on the live picture. For the app: force-close other video apps, lock the phone to the nursery camera, and note whether you are on home Wi-Fi or mobile data.
3. 3
   Stand in frame and clap once One sharp clap at chest height, in the camera's view. The person holding the feed starts the stopwatch at the clap (they can hear you, or you start together on a countdown).
4. 4
   Stop when the clap arrives on that screen Stop at the first frame that shows your hands meet, or at the first spike of sound on that speaker — pick one and keep it for every repeat. Write the seconds to one decimal if the watch shows it.
5. 5
   Repeat three times, then swap device Do three claps on the parent unit, then three on the phone app. If the set has a "local only" or Wi-Fi switch, run the app test twice: switch on (internet path) and switch off (handheld only). eufy's UK FAQ says the camera's Wi-Fi switch, when off, limits the camera to the monitor.
6. 6
   Repeat at bedtime traffic Run the same six claps after the household's streaming and work laptops are on. Which? already tests whether picture and sound drop as you move away; your seconds often grow when the 2.4 GHz band is busy.

Why is the parent unit faster than the phone app?

If the handheld shows the clap in a fraction of a second and the app shows you still standing in the doorway, the set is working as a hybrid: use the handheld for "do I need to go in?" and treat the app as a delayed check-in. The Lullaby Trust's position is still that a monitor does not replace an adult in the room for the first six months — a three-second app lag does not change that.

What makes the same clap slower tonight?

The camera did not get worse; the path did. Common UK-home changes:

• The phone left the house Wi-Fi. Remote viewing adds the broadband upload and the mobile network. Time that path on purpose if you use it.
• Mesh or extender hop. A phone that roamed to a weak node adds a retry. Stand where you actually sit at 8pm.
• Night vision plus high resolution. More pixels to encode. If you time in daylight only, do one dark-room run.
• Two viewers. A second logged-in phone can add load on cloud sets. Time with the usual number of apps open.
• Router lights on, internet dead. That is a different article — local viewing may still work; cloud viewing will not. The clap test on mobile data will hang or never show the clap.

How should I write the result down?

A single "the monitor is slow" note does not help at 3am. Keep four numbers:

1. Parent unit, home, lights on — median of three claps.
2. Parent unit, home, night vision — median of three claps.
3. App on home Wi-Fi — median of three claps.
4. App on mobile data (if you use remote viewing) — median of three claps.

If the app number is several seconds and you need a faster check, use the handheld for that night and leave the app for when you are out of the building. Which?'s security section also tells you to turn remote access off if you do not need it — that decision and this timing test belong together.

In short

In shortClap once in view, start a stopwatch on the screen you use, stop when that screen shows the clap. Do the parent unit and the app as two tests, at bedtime, on the network you will actually use. The seconds you write down beat any range copied from a comparison page.