Smart bulb buying guide: how to choose smart lights

Smart bulbs are usually the second smart home device people buy, right after a smart plug. They let you dim and switch lights from your phone or by voice, set schedules, shift from cool daylight to warm evening light and build scenes that change a whole room at once.

They are also easy to get wrong. A bulb that doesn't fit the lamp, fights with your dimmer or drops off Wi‑Fi every evening is worse than the cheap LED it replaced. This guide goes through the checks in the order that matters.

1. Choose the connection first

The radio inside the bulb decides which apps it works with, whether you need a hub and how reliable a large setup will be.

Matter is the safe default for new purchases. A Matter bulb is added with a QR code and can be shared between several platforms, so a household with an iPhone and an Android phone isn't forced into one ecosystem. Read what Matter is if the standard is new to you.

Matter bulbs come in two flavours. Matter over Wi‑Fi bulbs connect straight to your router. Matter over Thread bulbs use a low-power mesh network and need a Thread border router, which many recent smart speakers, displays and streaming boxes already include. Our Matter vs Thread vs Zigbee comparison explains the difference in detail.

Zigbee with a bridge (Philips Hue, IKEA and others) is still the most proven option for homes with dozens of lights. The bridge handles the bulbs locally and can expose them to Matter, so you get both reliability and cross-platform control. Our Philips Hue Matter setup guide shows how that works in practice.

Plain Wi‑Fi bulbs that only work with the maker's app are fine for one lamp, but each one is another client on your router. With 20 of them, weaker routers can struggle and bulbs may become unresponsive.

2. Match the fitting and the size

Check the old bulb before you shop:

• Base: E27 (standard screw in most of Europe), E14 (small screw), B22 (bayonet, common in the UK), GU10 (spotlights) and E26 in North America. Not every smart bulb range covers every base.
• Shape: A60 (classic pear), candle, globe, PAR spots and filament styles. A bulb that sticks out of a lampshade looks wrong and may run hot in enclosed fittings.
• Enclosed fixtures: some makers say their bulbs shouldn't be used in fully enclosed fittings. Read the box.

3. Brightness, colour temperature and colour

Ignore "watt equivalent" claims and look at lumens. Around 800 lumens is roughly what a classic 60 W incandescent bulb gave; around 1,500 lumens matches a 100 W bulb. For a main ceiling light in a larger room you may want more than one bulb or a brighter model.

Colour temperature is measured in kelvin (K). Low values (about 2,200–2,700 K) look warm and cosy; higher values (5,000–6,500 K) look cool and bright. Bulbs come in three tiers:

• Dimmable white: one fixed temperature, cheapest.
• Tunable white (white ambiance): adjustable from warm to cool. This is the sweet spot for most rooms, since you can use cooler light in the day and warmer light at night.
• Colour (RGB + white): millions of colours for accent lighting, gaming setups or parties. Worth it in a few places, not necessarily everywhere.

If accurate colours matter (kitchens, make-up, art), look for a published CRI (colour rendering index); 90 or above is a good sign. Many budget bulbs don't list it.

4. Solve the wall-switch problem

This is the most common disappointment. A smart bulb needs constant power to stay connected. If someone flips the wall switch off, the bulb disappears from the app and your schedules stop working.

Options, from simplest to most involved:

• Leave the switch on and use voice, the app or a wireless smart button or remote stuck next to the switch.
• Switch covers that stop the toggle from being turned off.
• Smart switches instead of smart bulbs, if a room has many ceiling lights on one circuit. Some need a neutral wire; check before buying, and use an electrician if you're unsure.

Also check what the bulb does after a power cut. Many let you choose in the app whether they come back on, stay off or return to the last state.

5. Watch out for dimmers

Smart bulbs do their own dimming. Putting one behind a traditional wall dimmer usually causes flicker, buzzing or failure. If a lamp is on a dimmer, set the dimmer to full and leave it, or replace it with a smart switch or a normal switch.

6. Do you need a bridge or hub?

For a handful of bulbs, no: Matter over Wi‑Fi, or Thread with a speaker you already own, is enough. Once you go past roughly a dozen lights, or want instant response and automations that keep running when the internet is down, a bridge or hub starts to make sense. Our guide on whether you need a smart home hub goes through the trade-offs, and running a smart home without internet explains which setups keep working offline.

7. Privacy and updates

Every connected bulb is a small computer on your network. Prefer brands that publish a privacy policy, deliver firmware updates and allow local control. Avoid cheap no-name bulbs that only work through an unknown cloud app: if the service shuts down, the "smart" part may stop working.

Quick buying checklist

• Right base and shape for the fitting
• Enough lumens for the room
• Tunable white, or colour where you really want it
• Matter, or a bridge-based system if you'll go big
• A plan for wall switches and dimmers
• Firmware updates and local control