Yes, smart bulbs use a small amount of electricity even when you turn them off from an app or voice assistant. The light-emitting part turns off, but the electronics inside the bulb stay awake enough to hear the next command.
This applies to Wi-Fi, Zigbee, Bluetooth, and hub-based smart bulbs from Philips Hue, LIFX, Kasa, Wyze, and similar brands.
Does this affect you?
Use this if you are wondering whether smart bulbs waste power while sitting idle, or if you are deciding whether to leave wall switches on so app and voice control continue working.
Why a smart bulb still draws power
A regular bulb becomes truly off when you cut power at the switch. A smart bulb is different when it is turned off through software.
- The socket still provides mains power to the bulb.
- The LED driver stops powering the light output.
- The radio and control chip remain powered so the bulb can receive commands.
- The bulb may also keep schedules, scenes, firmware checks, or network presence alive.
That small draw is usually called standby power or vampire power. Wi-Fi bulbs often use a little more standby energy than Zigbee or Bluetooth bulbs because they maintain a direct network connection.
How much does it cost?
The cost is usually small per bulb, but it can add up if you have many of them.
- A bulb drawing 1 watt all day uses about 8.8 kWh per year.
- At common U.S. electricity prices, that is often around $1 to $2 per bulb per year.
- A dozen bulbs could land roughly in the $15 to $25 per year range depending on wattage and local rates.
- Bulbs with local scheduling, presence features, or brighter status electronics may use more standby power.
The only precise answer for your bulb is to measure it. A plug-in watt meter can show real standby draw for lamps and plug-in fixtures. Ceiling fixtures are harder to test without electrical tools.
Can you eliminate the standby draw?
You can stop standby power by turning off the physical wall switch or cutting power at the fixture, but the trade-off is convenience.
- With power cut, the bulb cannot respond to the app.
- Voice assistants cannot turn it back on.
- Automations and schedules will not run.
- Some bulbs may appear offline until power returns.
Most manufacturers recommend leaving the physical switch on and controlling the bulb through the app, a smart button, a scene controller, or voice command. The standby cost is usually the price of keeping smart control available.
Standby draw matters more in vacation homes, rentals, large decorative installations, or rooms with many rarely used bulbs. For one or two frequently used bulbs, the convenience usually outweighs the small electrical cost.
Sources
- ENERGY STAR – Connected devices and standby power (2025)
- Philips Hue – Smart lighting frequently asked questions (2025)
- U.S. Department of Energy – Standby power overview (2025)