Efficiency is the comparison of the amount of light (lumens) produced by a given amount of electrical energy (watts). The more the lumens per watt the more efficient the bulb.

The Philips Dimmable A19 Smart Wi-Fi Wiz bulb is a top option ... Each string has dimmable multicolor LED bulbs that you can control with your voice or phone. They also support IFTTT applets ...

Those with 2700 K are closest to incandescent bulbs; ones with 3000 K are similar ... The Feit Electric A19/OM/800/LED is part of the Lightbulbs test program at Consumer Reports.