How far away baby's monitor can be from the parent unit is what determines a product's range. While many manufacturers offer a "line of sight" range to describe a monitor's range, it is not a good indication of how well it will work in your home with walls and interference. It doesn't matter how much you like a specific model or brand, if it doesn't work in your house, it simply isn't going to work. We tested both indoor range and open field tests to provide the best information, but remember that the values inside your home matter more than those in an open field, unless of course, you are leaving a baby alone in an open field (which we don't recommend).
It really depends on what you feel most comfortable with. There are audio monitors that allow you to listen to any noise coming from the nursery, vital monitors that track sleep and breathing and video monitors that add sight to sound. Babylist parents overwhelmingly choose video monitors. The security of seeing what your child is up to—like if they’ve gotten tangled in their swaddle, pulled their diaper off or climbed out of the crib—can be worth the extra cost of a video monitor.