Monitors for babies should have good video images that are clear and true to life, but they should also have quality sound that is easy to hear and clear enough that parents can quickly decide if they need to look at the viewing screen, go back to sleep, or get running to the nursery. So while you might consider video quality to be the most important metric for this kind of product, we rated both video and sound equally because, without one, the other doesn't much matter. If the sound is muffled, difficult to decipher, or not loud enough, then parents might miss baby's cries. If sound activation or thresholds for background noise don't work as described, then parents might lose sleep listening to a loud monitor. However, once alerted, you need a clear view of baby with enough details to determine baby's needs, day or night, or the video style monitor isn't much better than a sound only monitor.

One of the primary uses of baby monitors is to allow attendants to hear when an infant wakes, while out of immediate hearing distance of the infant. Although commonly used, there is no evidence that these monitors prevent SIDS, and many doctors believe they provide a false sense of security.[1] Infants and young children can often be heard over a baby monitor in crib talk, in which they talk to themselves. This is a normal part of practising their language skills.

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.