If you find that you always wake up feeling tired and groggy - especially in the darker winter months - then you might want to invest in a light alarm - a.k.a. a wake-up light or dawn simulator.

These are hybrids of alarm clocks and lamps, designed to wake you up with a steady build up of light that simulates a sunrise - complete with a shift of hue from reds and orange to brighter yellows and whites over the duration. The idea is that your body will react to the increasing light, even while you're asleep, preparing itself to wake up feeling naturally refreshed.

Light alarm buying advice

Not all light alarms are created equal, and there are a few key features to look out for - mostly to do with customisability. Let's break them down.

Light settings

The first thing to look for is how much control you get over the the actual light. Basic light alarms might just let you set an alarm time and that's it, but pricier models might give you control over the light intensity - the Philips Somneo has a scale of 25 different intensities - or the duration of the sunrise effect.

Sound settings

Easy to overlook, sound settings are arguably even more important than light customisability. While light alarms should help you wake up naturally from light alone, understandably most of us worry a bit about sleeping through it, so almost every light alarm includes some sort of optional alarm sound too.

What's important is to look at the sort of options you get here. Simple alarms might just include a beep - but this sort of abrasive noise is probably exactly what you want to get away from. Better models might include a range of soothing sound effects including birdsong or waves, an FM radio, or an AUX input so that you can connect your phone to provide audio through that.

Sunset modes

You also want to look out for optional sunset modes, which do the inverse of the light alarm: slowly dimming light to help your body naturally fall asleep. Again, look out for customisable settings, optional sound effects, or even breathing-focused modes to help you soothe yourself to sleep.

Other functionality

Finally, there are simple other features you might hope to see. Some are just basic alarm things that aren't always guaranteed: easy snooze modes or the option to schedule alarms to specific days. Otherwise you'll want to make sure you can save any customised alarm settings easily, and look out for other nice-to-haves like a USB port for charging a phone, or an easy way to switch the lamp on and use it as a reading light or nightlight.

SAD lamps

Finally, one point of distinction: light alarms are related to, but not the same as, SAD lights. SAD lamps are designed to treat the symptoms of seasonal affective disorder, and are required to emit at least 2,500 lux to be medically certified for the purpose.

Many light alarms have been clinically tested and shown to help with SAD symptoms and other seasonal disorders, but they're only a complement to a proper SAD light, not a replacement. We've also reviewed the best SAD lamps, so take a look if you want our recommendations.

Philips Somneo Sleep and Wake-Up Light

Philips Somneo Sleep and Wake-Up Light

The Philips Somneo is arguably the best light alarm on the market, and is only really held back by its high price - though it's arguably worth it for the feature set and the wild space age design.

Instead of physical buttons there are simple touchscreen controls built into the light itself, which you can use to customise your sunrise and sunset settings, with a range of 25 light intensities, various timings, and soothing noises from birdsong to temple gongs.

You can save two different alarm presets, though can't schedule them for specific days, so you'll have to remember to switch off your weekday alarm when Saturday rolls around.

In addition to a sunset mode for falling asleep there's a light-guided breathing mode to help you fall asleep. Beyond that, there are modern touches throughout: tapping the top to snooze, a dedicated low intensity light if you wake up in the middle of the night, FM radio, AUX input if you want to fall asleep to sounds from your phone, and even a USB-A slot to charge your phone too.

At the end of the day, this is an almost £200/$200 alarm clock, which is going to be more than most can justify spending. But if you can get over that hurdle, this is about as good as light alarms get.

Lumie Bodyclock Shine 300

Lumie Bodyclock Shine 300

Erring on the expensive side - though coming in cheaper than the Philips - is this fully featured light alarm from Lumie. It sits in the middle of the company's Bodyclock range and offers granular control over your wake up and bedtime routines, with a mixture of sounds and light settings at your disposal.

It has mixed LEDs that shine realistic combinations of white, orange and red to create a sunlight effect that isn’t too blinding and can increase and decrease gradually over 15-90 minutes at up to 20 different light levels.

It works best as a wake-up alarm. We opted for the maximum brightness scale over 30 minutes and found we were waking up naturally, also setting an alarm at the end of the time as a safe measure (we still don’t trust we’ll wake up with just the light!).

The alarm can be a beep or preset sounds like a stream train (weird), ping pong (also weird), waves (more conventional), or the in-built FM radio. Annoyingly if you turn it off at the mains all the settings reset to factory, which is pretty annoying, and the buttons on the unit mean it’s a fiddle to set up but once it’s working it’s a great product – there are just cheaper options.

Lumie Bodyclock Spark 100

Lumie Bodyclock Spark 100

If you like the sound of the Shine 300 but don't quite want to spend that much, you might want to consider the Spark 100, a cheaper model in the same Bodyclock range.

You can use it either as a light alarm to wake up or with a sunset mode to go to sleep, with customisable light intensity over the 30-minute modes.

Unlike the Shine 300 you can't change the duration of either the sunrise or sunset, and the audio options are also more limited: the only wake-up option is a beep, with none of the soothing waves or FM radio options available.

The more annoying omission is the inability to set an alarm schedule. While you can save a default time, you'll still need to remember to turn the alarm on every night before you go to sleep - enough of a risk that we can't imagine relying exclusively on this as your daily alarm.

The Spark 100 will get the job done though, and at less than £100 it's an affordable, no-frills option for people who just want a basic light alarm and don't mind missing out on fancy sound effects.