Light bulbs: LED lights LED lights explained

Thinking about making the switch to LED bulbs? Our experts reveal everything you need to know about LED bulbs - from what they are great at, where they are limited and whether you should buy them. 

If you are already convinced by LED light bulbs, make sure you get a Best Buy by looking at our Best Buy light bulbs

What are LED light bulbs?

LED bulbs with chips

LEDs use 90% less energy than a traditional incandescent

LED lights have been hailed as the future of home lighting as they use very little energy, claim to last a very long time and, unlike regular energy-saving bulbs, they are instantly bright when switched on.

As LED light bulbs for home use are relatively new, they tend to be the most expensive type of energy-saving light bulb and are mainly available in lower brightnesses. However, the technology is developing quickly and as LEDs become more popular, they are coming down in price. 

Prices typically range from £4 to £40 - take a look at our LED light bulbs rated page to see the best and worst LED lights.

LED bulbs differ from traditional incandescent bulbs in the way they produce light. While old-fashioned incandescent light bulbs passed electricity through a filament, LEDs produce light through the use of a semi-conductor that emits light energy when an electrical current is passed through it. 

This way of producing light is also different from regular energy-saver bulbs, which pass energy through mercury vapour to create UV light. This is then absorbed by a phosphor coating inside the lamp, causing it to glow.

What are LED bulbs great at?

LEDs are the most expensive type of regular light bulbs you'll see in the shops, but they do have advantages over the other types of bulbs.

  • LEDs are the most energy-efficient bulbs. They use 90% less energy than traditional incandescents and can sometimes pay for themselves through energy savings in just a couple of months. Compact Fluorescent Lamps (CFLs) are the most common type of energy-saver bulb, and they use 60%-80% less than incandescents. Halogens use 20-30% less
  • LEDs claim to be ultra long lasting - lasting for 25-30 years, depending on which one you buy and how you use it
  • LEDs give out their light almost instantly when you flick the light switch, so you don't have to put up with dim light while they get going
  • Our tests have found that LED and halogen bulbs work fine in low temperatures, whereas CFLs don't

What are the downsides of LED light bulbs?

Toshiba LED bulb

LED light bulbs use 90% less energy than incandescent bulbs

  • The LED market is currently a self-regulated market, so a CE mark on the bulb does not necessarily mean that it has been through all of the required quality checks. So the quality of LED bulbs can vary. Take a look at our independent reviews to make sure that you get a reliable bulb - go to LED bulbs rated
  • Until recently, LED light bulbs were generally only been available in lower wattages and lumen levels than other types of light bulb. So although they are quick to reach their full brightness and suffer no decrease in performance over time, they are often only available in dimmer varieties than CFL and halogen bulbs. This is improving all the time, however, with brighter LEDs becoming available
  • Some people don't like the quality of light given out by LED light bulbs, as some can produce a cooler bluish light. The best LEDs will be indistinguishable from your old incandescent bulbs and be able to produce a nice warm light
  • We have heard some cases where a small number of LED light bulbs can interfere with DAB radio signals. We test all bulbs for this annoying anomaly so you won’t be surprised when you get it home and switch it on
  • To be able to dim LED lights you may need to upgrade to a dimmer that recognises low electrical loads. The packaging should say whether LEDs are dimmable, but check with the manufacturer if you are unsure
  • CRI or Colour Rendering Index which is a measure of how well a light source accurately reveals various colours. Halogen and traditional incandescent get in the high 90s on this measure. For now, the best LEDs get a score in the mid 80s.

Take a look at our guide to buying energy-saving light bulbs for more information on brightness levels, lumens, light bulb shapes and fittings.

Should I buy LED bulbs?

Yes. These bulbs are the most energy efficient, they are long lasting and get bright the instant you flick the light switch. Make sure you look at our light bulb ratings before you buy, as quality can vary.

Buy one LED bulb first, to see if you like the spread and colour of light before committing to replacing more bulbs in your home.

This is a fast-paced market so you may find that if one of your new LEDs fails after a year, you might not be able to find an identical replacement. To avoid a new bulb having a different spread or colour of light to what you already have, buy a spare replacement bulb at the time of your initial purchase.

Pros: LEDs are the most efficient type of bulb, have great claimed longevity, give instant light, work in low temperatures
Cons: Quality varies, some higher wattage-equivalent brightnesses not available

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