Best sunrise alarm clocks: do they actually work?

With claims that they can boot your circadian rhythm into gear, we've taken a look at whether or not you should pick up a sunrise alarm clock.

Can these gadgets help you sleep better? We've delved into the evidence for – and against – sunrise alarm clocks with the help of one of our scientists, Ruby Gordon.

Plus, we've picked some popular models if you're in the market for a new wake-up call.

Eat well, live better and stay healthy: sign up for our free monthly Food & Health newsletter for the latest insights delivered straight to your inbox

What is a sunrise alarm clock?

A sunrise alarm clock is a clock that gradually gets brighter to wake you up with light instead of the loud, sometimes grating, alarms we're typically accustomed to.

There are claims that this can help you finish a sleep cycle, influence your circadian rhythm and help you wake up 'more naturally'.

Can sunrise alarm clocks help you sleep better?

According to the National Heart, Lung and Blood Institute of the USA, most people complete between four and six cycles of REM (rapid eye movement) and non-REM sleep stages per night. Interrupting a sleep cycle suddenly might leave you feeling groggy, or even disorientated – although the evidence for that is still unclear.

Additionally, each of us has what's called a circadian rhythm; an internal clock that largely aligns with sunlight – leaving you sleepy at night and awake during daylight hours. That said, not everybody has the same circadian rhythms. If you're a 'night owl', you won't have the same circadian rhythm as an 'early bird'. In a study by the Oxford University Press, it's even thought your circadian rhythm could be genetic.

REM sleep and your circadian rhythm can influence your sleeping patterns and help you naturally wake up. While it's nice to wake up whenever you'd like, most of us don't have that luxury and need to be up at specific times for work, to take care of kids or get chores done.

Enter sunrise alarm clocks. They supposedly help you wake up 'naturally' within a chosen timeframe, which can leave you feeling better rested. Manufacturers claim they can help you sleep better – but there are some major caveats.

Read our 7 expert tips for better sleep

Expert verdict: should you buy a sunrise alarm clock?

Which? scientist Ruby Gordon has reviewed the available scientific evidence on sunrise alarm clocks.

She advises: 'The main claimed benefit of this wake-up method is to support your circadian rhythm, which is our internal clock regulating important physiological processes such as sleep-wake pattern, hormones, stress, etc. 

'By helping you to wake up gradually, sunrise alarm clocks may mitigate symptoms of sleep inertia, which is the feeling of grogginess, disorientation and drowsiness immediately after waking up. Some research suggests this can be caused by being suddenly woken up while you're in certain phases of sleep. However, the exact cause is still unknown. 

'Moreover, there is a lack of research and scientific studies to back up these claims, and more research is needed to assess if and how this can improve our health.'

However, that doesn't mean they're not worth trying out. 

Ruby continues: 'Despite this, there is anecdotal evidence of users benefiting from this wake-up method – including myself. While it's unlikely to have a significant impact physiologically, I've found that my overall wellbeing is improved when getting out of bed, and it helps me start my day after using a sunrise alarm clock. 

'If you struggle with morning grogginess or would like to try a calmer method to start your day, this could be a helpful lifestyle aid to add into your routine. However, be aware that the scientific research is lacking and whether this is worth while for you is likely to be a personal preference.'

Wondering what our experts use for better sleep? Read their 10 sleep essentials for a great night's rest

What to look for in a sunrise alarm clock

When it comes to features, there are a few key things to look out for in a sunrise alarm clock:

• Brightness – probably the biggest indicator of 'how well it will work'. Light intensity is measured in lux, with a candle at 1 metre away being 1 lux, and a bright sunny day being between 80,000 and 100,000 lux (even here in the UK). If you're by a window inside, that's around 3,000 lux – which, theoretically, is what should be impacting your circadian rhythm. Sunrise alarm clocks are typically between 250 and 300 lux. That said, if it's just a metre or two away from your face, the light intensity can drop further. In this instance, the brighter a sunrise alarm clock is the better.
• 'Medically approved' – in short, neither SAD lamps nor sunrise alarm clocks have enough evidence to be 'medically' effective, and the NHS doesn't provide light therapy for these reasons. At best, this label doesn't mean anything. At worst, it's misleading – it would imply that it's been rigorously tested in labs and in peer-reviewed studies, even though it probably hasn't.
• Extra features – if you sleep better with a white-noise machine, some sunrise alarm clocks come with sleep sounds. Others might include a built-in radio, or charging ports, or extra light functions such as a 'wind down' mode for when you go to sleep. If you want to try these too, it might be worth picking up a 2-in-1 device.

Popular sunrise alarm clocks

As Ruby says, it doesn't hurt to try out a sunrise alarm clock. If you think it will help, we've picked some popular models to help you narrow your search.

Lumie Sunrise Alarm

• Dimensions: 18cm x 17cm x 9cm (H x W x D)
• Brightness: 10 levels of light (maximum 70 lux depending on area)
• Sunrise duration: fixed

This popular sunrise alarm clock from Lumie has a 30-minute sunrise timer that gradually increases the levels of light from one to 10. You can also set it to a 'sunset' mode for when you're winding down.

Sadly, we couldn't find any lux ratings. However, we found its maximum brightness is 70 lumens. This translates into about 70 lux for a 1 sq m area.

If you're looking for an extra kick out of bed, you can also set an optional traditional alarm.

Philips SmartSleep

• Dimensions: 19.2cm x 19.9cm x 14.6cm (H x W x D)
• Brightness: 300 lux
• Sunrise duration: adjustable

Like other sunrise alarm clocks, this one from Philips uses coloured light to wake you up over a span between 20 and 40 minutes.

This one features seven different wake-up sounds that play as the clock lights up in the morning. There's also an FM radio built in, and it has ports to charge your smartphone.

You can pick it up from Philips (£170) or compare prices from other retailers below:

Philips Hue lighting system

• Smart home lighting system
• Brightness varies: you can calculate lux with this equation: lux = lumens (from all lights) ÷ area (of the space you want lit) 
• Lamps, light bulbs, and sunrise alarm clocks are available 

Although the Hue lighting system isn't so much a dedicated sunrise alarm clock, it can be set to have a 'sunrise' mode, which gradually brightens all devices in a zone to mimic a sunrise. It might help to have the whole room lighting up rather than just a lamp on your bedside table. Plus, you can set specific lighting scenes in the evenings, which can help you wind down.

It might be worth considering getting some smart lightbulbs and lamps to install in your bedroom. 

You can view the range of lights from Philips, or compare prices on a variety of products from the Hue range below: 

The Sun itself

• Circumference: 4,379,000km
• Brightness: up to 300,000 lux
• Weight: 1,989,000,000,000,000,000,000,000,000,000kg

Obviously, in the summer it might be worth using the actual sun to help you wake up instead. Luckily for us, sunshine is free (when we get it). So instead of buying a gadget, try leaving blinds or curtains open and waking up when the sun rises.

This can help you decide whether you think a sunrise alarm clock will be helpful in the winter.

What about the opposite of a sunrise alarm clock? Read our guide on the best eye masks for sleep – they go well with a pair of the best ear plugs, too

Should you get a SAD lamp instead?

If you're struggling to wake up, or are sleeping more, you could be suffering from seasonal affective disorder (SAD).

Some sunrise alarm clocks have built-in SAD lamps, as your circadian pattern is affected by environments with lower light, such as during the winter.

We've delved into the evidence with our experts in our guide to SAD lamps.

Can a sunrise alarm clock help with insomnia?

There still hasn't been enough research or standardisation into sunrise alarm clocks to know for sure. 

What's probably a better option is listening to the advice from organisations such as the NHS, which says that insomnia can often be improved by changing your sleep habits. Much of it can be done for free.

The NHS recommends:

• Going to bed and waking up at the same time every day.
• Avoiding smoking, drinking alcohol, tea or coffee at least six hours before going to bed.
• Relaxing for at least an hour before bed.
• Not watching TV or using your phone right before bed.
• Exercising regularly, but not within four hours of bedtime.
• Making sure your bedroom is dark and quiet, and that your mattress and pillows are comfortable.
• Not napping during the day.
• Sticking to your regular sleeping schedule instead of sleeping in after a bad night's sleep.

If you're doing all these and are seeing no changes to your insomnia, it's probably best to see a GP.

That said, if you think a sunrise alarm clock can help you change your sleeping habits for the better, it might be worth getting one. However, don't expect it to be a fix-all for insomnia.

Looking for a comfier bed? Read our guides to the best mattresses, best pillows, and best duvets – all rigorously lab tested by our experts 

Is it better to wake up to light or sound?

Sunrise alarm clock manufacturers claim their products can emulate waking up more naturally, and that it's better for you. 

As Ruby said: 'By waking up gradually, sunrise alarm clocks may mitigate symptoms of sleep inertia, which is the feeling of grogginess, disorientation and drowsiness immediately after waking up. Some research suggests this can be caused by being suddenly woken up [such as by a regular alarm] whiin certain sleep phases. However, the exact cause is still unknown.'

So, to risk sounding like a broken record, we unfortunately don't have enough evidence yet for a definitive answer. 

Meet our experts

Ruby Gordon, scientific advisor at Which?

Ruby has a first-class honours degree in psychology and has experience conducting both small and larger-scale research studies, so she knows how to dissect a research paper and get the facts straight.

As part of the Which? in-house science team since 2022, Ruby has advised across more than 30 projects covering everything from air pollution during cooking to finding the best tech.