How to make a 3-way lamp smart

There is no smart 3-way bulb. For most people the right answer is a smart plug with the 3-way bulb left in place - you get app control, voice and schedules, and the low-medium-high knob keeps working as it always did. If you want to change brightness from your phone, that is a different build: a plug-in dimmer and an ordinary dimmable bulb, with the 3-way bulb removed.

The reason this is awkward at all is that a 3-way lamp and a smart bulb are solving the same problem - brightness control - in two incompatible places. The lamp solves it mechanically, in the socket. The smart bulb solves it electronically, inside the glass. Put them together and each one gets in the other's way.

Before buying anything, it is worth being sure which "3-way" you have. A 3-way lamp is one lamp whose knob clicks through low, medium, high and off. A 3-way switch is two wall switches controlling one light from opposite ends of a room - a different product entirely, covered in three-way and multi-location switching. This page is about the lamp.

This is worth two minutes, because every problem below follows from it.

An ordinary bulb socket has two electrical contacts: the threaded metal shell, and a single contact at the bottom center. A 3-way socket adds a third - an off-center ring contact alongside the center one. A 3-way bulb has the matching pair of contacts on its base, and behind them two separate filaments or LED circuits of different power.

The knob then cycles through four states: nothing energized, the ring contact alone, the center contact alone, and both together. In the classic 50/100/150 W bulb that is a 50 W circuit, a 100 W circuit, and the two running at once for 150 W. Three brightness steps out of two circuits, with no dimming involved anywhere - which is why 3-way LED bulbs are sold as non-dimmable. They are switched, not dimmed.

This is the right answer for most 3-way lamps. The plug sits between the lamp and the wall and switches mains power. Everything above the plug - socket, knob, 3-way bulb - carries on working exactly as it did.

What you gain: app and voice on/off, schedules, away-from-home control, and inclusion in scenes with the rest of the house. What you give up: the brightness step is still chosen by hand at the lamp. You can turn the lamp on from your phone; you cannot turn it on at low from your phone.

In practice that matters less than it sounds, because a rotary 3-way switch is mechanical and holds its position through a power cut. Leave the knob on the step you normally want and the lamp comes back to that step every time the plug restores power. People use this as a feature: set it to low, schedule it for the evening, and reach over to click it to high when they want to read.

The plug: the TP-Link Kasa Matter Smart Plug EP25. Matter, so it works with whichever ecosystem the rest of the house uses rather than locking the lamp to one app.
Who should skip it: anyone who wants brightness control from the phone - that is route 2 - and anyone whose lamp is nowhere near an outlet they can reach, since a smart plug has to be accessible to be reset.

The bulb to pair with it: the Feit Electric 3-Way LED A21. 50/100/150 W equivalent with all three steps published - 800, 1,600 and 2,200 lumens - at 2700K. A 3-way socket is only worth keeping if the bulb in it actually delivers three useful steps, and plenty do not publish the figures at all.
Who should skip it: anyone going to routes 2, 3 or 4, where a 3-way bulb is the wrong bulb. It is non-dimmable by design, so it must never go on a dimmer.

If what you want is brightness from your phone, this is the build - and it is the one most people should choose over a smart bulb.

You take the 3-way bulb out, put an ordinary dimmable bulb in, set the lamp knob to a position that powers the bulb, and leave it there forever. A smart plug-in dimmer then does the dimming electronically, between the wall and the lamp.

The Lutron Caseta Plug-In Lamp Dimmer (PD-3PCL). App, remote, or the buttons on the unit itself, and Lutron's dimming is the best in the category at the bottom of the range, which is where cheap dimming falls apart. The buttons on the unit matter more than they sound: a guest can use the lamp without your phone.
Who should skip it: anyone who wants color as well as brightness - that is route 3 - and anyone unwilling to give up the physical three-step knob, since this route retires it.

Why this beats a smart bulb for most people: the light quality is whatever bulb you choose rather than whatever the smart bulb maker built, you can use a high-CRI bulb, and when the electronics eventually fail you replace a $30 dimmer rather than re-buying bulbs. The full comparison is in smart bulb vs smart plug for a lamp, and the dimmer options are in the best plug-in dimmers.

This works, and it is the only route that gets you color. But the socket is now working against you in two ways and you should know both before you buy.

First, the dead click. A smart bulb has one bottom contact, so one position in the knob cycle leaves it dark, as described above. Nothing is broken; there is simply a position in the rotation that does nothing.

Second, and more annoying: the knob cuts power. A smart bulb has to stay powered to stay on the network. Every time someone clicks the lamp to a position that de-energizes it, the bulb drops off and stops answering the app, voice assistant and schedules until power comes back. In a household where other people use the lamp, that is a recurring support call pointed at you.

If you do this: the Sengled Matter A19. Matter over the house network, dimmable in the app, and no proprietary hub to buy. Set the lamp knob to a position where the bulb is powered, then treat the knob as off-limits.
Who should skip it: anyone whose lamp is used by people who will keep clicking the knob - which, in a shared living room, is everyone. For that lamp, route 1 or route 4 will cause far fewer complaints.

The honest way to run this route is to stop treating the lamp knob as a control at all. If that sounds unworkable in your house, route 4 removes the temptation permanently.

The clean fix, and cheaper than any of the gear above. Swap the 3-way socket for a plain on/off socket, and the dead click and the accidental power cuts both disappear because there is no longer a position that de-energizes the center contact mid-rotation. You are then free to run route 2 or route 3 with nothing fighting you.

The DiCUNO UL Listed on/off socket. UL Listed, which a good deal of this category is not, and the cheapest part named on this page by a wide margin.
Who should skip it: anyone not comfortable opening up a lamp. This is mains wiring inside a device that sits on furniture - straightforward, but not a job to learn on. A lamp repair shop will do it for very little.

The job itself - which wire goes to which screw, the underwriter knot, and how to tell a dead socket from a dead cord - is set out step by step in rewiring a lamp. If you are not sure what the parts are called, the parts of a light fixture names all of them.

A shared living room lamp other people use. Route 1. The knob keeps working for everyone else, and nothing you add can be broken by somebody using the lamp normally.

A bedside lamp only you touch. Route 2 or 3. You want brightness from the phone at night, and you are the only person who can disturb the knob.

A lamp you want on a schedule while away. Route 1, with the knob left on medium. Simple, and there is no bulb to fall off the network while you are gone.

A rental you will leave. Route 1 or 3 - both unplug and unscrew with nothing left behind. Route 4 is reversible too, but keep the original socket in a drawer if the lamp is the landlord's. The renter's set is in renter-friendly smart lighting.

You want color. Route 3, and ideally route 4 first so the socket stops interfering.

The lamp is old and the socket is tired anyway. Route 4 regardless of what else you do - a socket that flickers when the bulb is nudged will keep doing it behind whatever smart gear you put in front of it.