How to buy the best light bulbs

The obvious choice for new bulbs is usually LEDs, but there's also energy-saving CFLs, halogen bulbs, spotlights and dimmers to consider. And don't forget smart lighting, which hooks up to your wireless home hub. 

This comprehensive guide compares the pros, cons and running costs of the different types of light bulbs. It also offers advice on how to dispose of the old ones.  

Be inspired to make home improvements. Sign up for our Home newsletter, it's free monthly

LED light bulbs

LED lights use very little energy, are claimed to last a very long time and, unlike regular energy-saving bulbs, are instantly bright when switched on. Most smart light bulbs are LEDs.

They produce light through the use of a semi-conductor that emits light energy when an electrical current is passed through it. They are the most energy-efficient option, using 90% less energy than traditional incandescent bulbs, which were phased out in the UK in 2009.

LEDs also have a significantly longer lifespan than halogen and CFL light bulbs, estimated at around 25,000 hours compared to 2,000 hours for halogens and 10,000 hours for CLFs. 

Plus, prices are getting lower all the time. While the brightest bulbs can still set you back around £20, most cost less than £10, and the energy savings they provide make them well worth considering.

Pros of LED bulbs

• LEDs use 90% less energy than traditional incandescents, and can sometimes pay for themselves through energy savings in just a couple of months.
• They last for 25-30 years, depending on which ones you buy and how you use them.
• They give out light almost instantly when you flick the light switch, so you don't have to put up with dim light while your LEDs get going.
• They work fine in low temperatures.

Cons of LED bulbs:

• Some people don't like the quality of light given out by LED light bulbs, as they can produce a cooler, bluish light.
• To dim them, you might need to upgrade to a dimmer that recognises low electrical loads. The packaging should say whether LEDs are dimmable.
• It's tricky to get a consistent look in your home if you mix different LED brands and types. The colour temperature and colour rendering index (CRI) can vary more than with traditional light bulbs.

Energy saving light bulbs (CFLs)

Energy saving bulbs, also known as compact fluorescent lamps (or CFLs) were the original energy-efficient alternative to incandescent bulbs. CFLs typically use 60-80% less energy than incandescent lights.

CFL bulbs use an electric current to excite gases within the bulb, causing a phosphorus coating on the inside to glow, producing light. Through this method, less energy is lost to heat and the bulb is more energy efficient. Some CFLs take a few minutes to reach full brightness.

Most modern dimmer switches should work with CFL bulbs, although some older ones might not be compatible.

We anticipate that CFLs will gradually become harder to find with the wider industry and new government legislations shifting towards LED usage.

Pros of energy saving light bulbs

• CFLs are reasonably cheap, with prices starting as low as £3.
• They pay for themselves in energy savings fairly quickly.
• They have a long lifespan of around 10,000 hours (or roughly about 10 years of use).

Cons of energy saving light bulbs 

• They take a bit of time to warm up and brighten when they're first switched on. This means CFLs aren't always the best choice for stairs or bathrooms.
• Some CFLs aren't suitable for use with dimmer switches.
• These bulbs tend to work poorly in cold temperatures, making them less suitable for unheated rooms or outdoor spaces, such as a garage.
• Some CFLs look significantly different compared with old-style bulbs and it can be tricky to get them in certain shapes and sizes, such as small candle bulbs.
• We expect they'll become harder to obtain over coming years as the industry shifts its focus more fully on to LEDs.

Looking for more ways to make lower your energy bill? Read our advice on how to make your home more energy efficient.

Smart light bulbs

Smart light bulbs are internet-connected, meaning you can control them from a connected device – from anywhere in the world if you needed to – as long as you have a data or wi-fi connection. Most are powered by LEDs, and therefore have cheaper running costs than other types of bulbs.

You'll usually need a smart hub to set up smart light bulbs, which allows your bulbs to communicate with your internet router. Make sure your bulbs and smart hub are compatible – for example, Philips smart bulbs will only work with a Philips Hue Bridge.

You could set up one hub to control multiple devices in your smart home, such as your security system or radiator valves.

Some smart bulbs will still function without a smart hub. For example, certain bulbs from LIFX have built-in wi-fi, which means they work independently.

Other smart lights work over Bluetooth as well as (or instead of) wi-fi. This means that although you can control the bulbs remotely using a phone or tablet, you need to be within a specific range. You won't be able to control Bluetooth bulbs from outside this range (often around 30ft).

Most smart lighting systems are compatible with voice commands through Google Assistant or Amazon's Alexa, making them a good hands-free option.

Many smart bulbs can also change colour. You can expect to spend up to around £50 for a single colour-shifting smart bulb. If you're shopping for a smart bulb that just switches between warmer and cooler white tones, expect to pay £10-£30.

Pros of smart light bulbs

• You can control smart light bulbs while out of the house, which is handy if you accidentally leave a light on.
• Smart bulbs are made with existing lamps and light fixtures in mind and most come with Edison caps, bayonet caps or both.
• As an extra layer of security, you can turn on your lights remotely to deter burglars.
• Many smart home hubs come with motion sensors – you can set them so that your smart bulbs turn on when they detect movement.

Cons of smart light bulbs

• If you're looking to upgrade multiple regular bulbs to smart alternatives, costs can ramp up.
• You won't be able to control your smart light bulbs remotely if you have wi-fi or mobile signal issues.
• Bluetooth-only smart bulbs can't be controlled beyond a certain distance.

Interested in hooking up your own smart home? Don't miss our guides to the best smart thermostats, smart radiator valves, and smart plugs.

Dimmable light bulbs

Dimmable light bulbs allow you to adjust the brightness of the light they produce by regulating electricity flow to the bulb. This is sometimes done with a dimming switch on your wall, or for smart bulbs, via an app, remote, or voice command. 

There are two types of dimming systems. Older-style dimmers tend to be 'leading edge', designed to work with incandescents and halogens. They have a high minimum wattage load, making them less useful for low-energy LED lighting. 

'Trailing edge' dimmers are more modern and have a much lower minimum load, making them more compatible with LEDs. They also offer smoother dimming and less of that buzzing sound you get with older dimmer switches. These days, most dimmable lights are LEDs.

You'll need to make a few checks to see if your home set-up is compatible with dimming:

LED dimming checklist

• Buy LED bulbs that state they are dimmable.
• Check whether your dimmer switch is designed for LEDs, and calculate the total wattage in the circuit to see if it's in the right range.
• Switch to a trailing-edge dimmer if needed. Check the LED bulb manufacturer's website as they may have specific recommendations.
• Avoid mixing LEDs and old-style (incandescent, halogen or CFL) bulbs in the same fitting.
• Ideally, use identical LED bulbs (ie the same brand/spec) in one fitting for consistency. Buying multipacks, especially of LED GU10 spotlights, is often cheaper, too. 

Halogen light bulbs

Halogen light bulbs comprise a filament enclosed in halogen gas, meaning they can burn hotter than an incandescent but still use less energy. While more energy-efficient than traditional incandescent bulbs, technology has moved on and there are now much more environmentally friendly options.

These light bulbs were phased out and eventually banned by UK government in 2021 to improve energy-efficiency standards in electrical appliances, so you won't be able to buy them anymore. You can find out more on the Gov.uk website.

Halogens are more expensive to run than LEDs and they don't last nearly as long, so we suggest swapping them out sooner rather than later. And don't wait for your halogen bulbs to die before making the switch to an environmentally friendly LED. 

LED spotlights

Spotlights are light fittings typically mounted onto a surface and fixed onto a wall or ceiling. They provide multiple beams of light, and although the lights are fixed to one unit, each 'spot' can be adjusted to point in a different direction. It’s also possible to buy single spotlights.

Since the banning of halogen light bulbs, LEDs are the most popular, longest-lasting, and most energy-efficient option for spotlights. They are a particularly popular choice in kitchens and hallways.

Spotlight brightness is measured in 'useful lumens', which is slightly different to how brightness is calculated for a conventional bulb. The number of useful lumens is defined as the light that falls within a 90-degree cone.

As a rough guide, 300-400 lumens per square metre is recommended as a good ambient lighting level in a kitchen or hallway, rising to 700-800 lumens per square metre if you have a worktop area that you want brightly lit.

You can get dimmable spotlights, though not all are dimmable as standard, so check the packaging before you buy. 

If you think you might need an electrician, head to Which? Trusted Traders for our recommended providers.

Where to buy light bulbs

Several popular online retailers stock light bulbs.

• Amazon has a massive selection of light bulbs, including budget-priced smart bulbs and energy-efficient LED multipacks.
• Argos sells a selection of light bulbs split by category: Edison screw (ES), bayonet (BC), small Edison screw (SES), GU and smart bulbs.
• B&Q has a mix of LED bulbs, decorative LEDs and smart bulbs. 
• Screwfix sells regular LED lights alongside smart light bulbs from big name brands including Hive, Philips Hue and TCP.
• Ikea has hundreds of light bulbs to choose from, including £2 LEDs as well as internet-connected bulbs that live within the brand's Ikea Home Smart ecosystem.
• Lightbulbs Direct offers a wide selection of LEDs and CFLs.

How to dispose of light bulbs

• CFL bulbs If you want to get rid of an old CFL bulb, avoid chucking it in with your regular rubbish. CFL bulbs contain tiny amounts of mercury, which means they'll need to go to a recycling centre or one of your local recycling drop-off points.
• LED bulbs These last a long time, so you shouldn't need to get rid of one often, but when you do, you can just put the bulb in your normal household waste. Bear in mind that warranties on LED bulbs typically last between two and four years, so if the bulb fails within this time you should be able to get your money back. Check the box for details, and contact the retailer or the manufacturer’s customer service department.
• Halogen bulbs These aren't recyclable because they contain a series of fine wires that are difficult to separate out. Wrap the bulb in case it shatters, then put it with your normal household waste.

For more details on getting rid of your old electronics, see our expert guide on how to recycle electrical items.

Be inspired to make home improvements. Sign up for our Home newsletter – it's free monthly