If your internet goes down, your baby monitor goes down. A wifi baby monitor uses your home's internet connection to communicate to servers, then to your app. So if your internet connection goes down, then you will no longer be able to stream video of your baby. That's a huge consideration to keep in mind because you never know when your internet will slow down or simply stop working for several minutes or hours, and you will be stuck without a working baby monitor. There are a few wifi baby monitors that will still communicate locally (within your home's network) when the internet goes down, such as the Lollipop or Nanit. They do this by switching from internet to local area network when an outage is detected, so you can have confidence that if you're connected to your home wifi you'll still see your baby.
We prefer RF monitors to Wi-Fi, but if you’re seeking the latter, we don’t recommend getting the Ezviz Mini, the Palermo Wi-Fi Video Baby Monitor, or the LeFun C2, all of which Amazon reviewers report have connectivity issues, among other problems. We dismissed two other Wi-Fi monitors we tested—the Arlo Baby by Netgear and the Evoz Glow Baby Monitor—for being harder to set up than the iBaby Wi-Fi monitor. They were not notably better than the iBaby in some other way, and they share the other significant shortcomings of Wi-Fi monitors as a category.
Wireless encryption: This ensures that no one else can tap into your monitor’s “feed” and see what’s going on in your house. WiFi-enabled monitors are great for portability and range, but may be more susceptible to hacking. If you go this route, be sure to secure your home wireless network and keep the monitor’s firmware updated. Otherwise look for digital monitors with a 2.4 GHz FHSS wireless transmission.