One minor but potentially annoying flaw: The “on” lights on the parent unit are a touch bright, and you may be more sensitive to them since you’re likely to have the unit within view as you sleep. They appear as greenish yellow light from the face of the unit, and a charging light, which is blue when it’s fully charged. Depending on how sensitive you are to light, you may want to lay the display face down on a nightstand or cover the status lights with tape.
We tested monitors daily over a period of several months, in three houses: one nearly 100 years old with plaster walls, plus a newer home with standard drywall construction, and a two-level 1960s home with a driveway on another level from the kids’ rooms. We tried the cloud-based monitors with two routers to be sure that any connection issues were with the monitors themselves and not the Internet connection.
If you aren't interested in having a video baby monitor, the VTech DM221 is the very best audio-only monitor you can buy. You can listen in on your baby or get vibration and light-based alerts when the monitor is in silent mode. The five LED lights indicate the level of sound so you can tell whether your baby is cooing quietly or shrieking for mom and dad.
As you'd expect, the talk-back functionality and audio quality on the VTech are great—easily better than the rudimentary talk-back features on our video monitor picks. With the battery lasting about 19 hours on a full charge, this monitor has the strongest battery life of any in our test. Rated to a range of 1,000 feet, it exceeds the range of our pick (700 feet) both as advertised and in practice during tests.
This monitor is known for its zoom lens, included in the box, that lets you see your baby up close even if you have to position it farther away from the crib. You can use the monitor to remotely adjust the camera, and you don’t have to worry about plugging the monitor in overnight—it can sit on your nightstand for up to 10 hours in the power-saving mode (similar to sleep mode on your computer, but it still provides sound monitoring while the display is off) and up to six hours with the display screen constantly on.