Your phone might not have great battery life. Many parents who use a wifi baby monitor come to the realization that their smart phone battery life isn't so great when they are streaming a live video and audio feed from their baby monitor. If you have a newer iPhone or Android device, it will probably do pretty well, but if you have an older phone the batter is probably a bit weaker already and you will notice your battery life dropping pretty quickly during use. So definitely consider battery life and charging options for your smart phone when you are choosing between a self-contained versus wifi baby monitor.
When it comes to video monitors, you'll want to make sure that the one you're buying offers night vision and a decent resolution. Most baby monitors with a dedicated viewer sadly have low VGA resolutions, which are much worse than the majority of smartphones you can buy these days. A few have a 720p HD resolution, which is decent. We hope more baby monitors go that route in the future.
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.