I have a number of Midcentury and later lamps that switch on and off with a knob on the fixture: turn it one way for on, turn it back for off, and dim or brighten the light by turning it. Every description for “dimmable LEDs” contains a laundry list of compatible brands of dimmers (I assume these are all wall switches), but none answer this simple question: will the standard dimmer knobs on old lamps adjust dimmable LEDs?

  • It is almost like seeing if a PC will work with Linux, they only test so many, and if yours do not make the list, you can take a chance. I think most dimmers work the same, but newer dimmers might work better. Usually LEDs and dimmer switches are on the cheap side, compared to a nice lamp.
    – crip659
    Aug 1, 2023 at 22:35
  • Nothing to do with lamp age, the dimmer and the dimmable lamps are responsible
    – Traveler
    Aug 1, 2023 at 22:35

2 Answers 2


The answer is: it depends.

Older dimmer switches, particularly those found on lamps, typically use a technology known as a triac dimmer or an incandescent dimmer. These dimmers work by chopping up the AC current to reduce the amount of energy that reaches the bulb. This works well for incandescent bulbs, but it can cause problems for LEDs, such as flickering or not dimming properly.

Dimmable LEDs are designed to work with dimmer switches, but the compatibility is often with modern, LED-rated dimmer switches, not necessarily older incandescent dimmer switches like the one on your lamp. That's why you see a list of compatible dimmer switches on the packaging or in the product description for dimmable LED bulbs.

However, this doesn't mean that dimmable LEDs won't work at all with your old lamp's dimmer switch. Some people have successfully used dimmable LEDs with older dimmer switches. It's just that the performance might not be optimal, and you could experience issues like flickering or a limited dimming range.

If you want to use dimmable LEDs with your lamp and ensure optimal performance, you might need to replace the old dimmer switch with a new, LED-compatible one. This might not be feasible with some lamps, and in some cases, the cost and effort might not be worth it.

The best way to know for sure is to try a dimmable LED bulb with your lamp and see how it performs. If you're happy with the performance, great. If not, you might need to consider other options, like using a non-dimmable LED bulb or sticking with incandescent bulbs if dimming is important to you.

  • Thank you! That’s exactly what I needed to know. As a backup, I’m gonna hoard incandescent bulbs for all the pharmacy lamps I have.
    – Edward
    Aug 2, 2023 at 1:30

All you can do is try it. Get a bulb and screw it into the lamp and see what happens. It might just work. I have 6 dimmers I installed in the very early 80's for standard incandesent flood lights. I recently went with LEDS and was surprised to see that they all worked with the new bulbs. It's been a few years and all is well.

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