Sleep trainer clocks compared: how to choose one
A sleep trainer clock, also called a sleep training clock or a children’s sleep clock, shows a young child when it is still sleep time and when it is OK to get up. There is no single best one. They differ in how they show the rule, how you set them and what they need to run, and the right one depends on your child and your house. This page sets out the kinds, what to check, and the clocks UK parents ask about most.
If you want the basics first, what an OK to wake clock is, and when to start covers how they work and the age they suit.
The three kinds
- A clock with a picture face. The screen shows a night picture until the wake time and a morning picture after it. The best known in the UK is the Tommee Tippee Groclock.
- A light that changes colour. One colour means stay in bed, another means get up. Some have a face that opens its eyes. These are sometimes called red light green light clocks or traffic light clocks.
- An app on a tablet or phone. The screen you already own shows the night and the morning. Snoozaroo is one.
What to check before you choose
- How it shows the rule. A picture or a colour is all a young child needs. Numbers help nobody at that age. Some clocks only switch at the end; others count the night down, so a child who wakes early can see how long is left.
- How you set it. Most are set with buttons on the clock, which means a change is made standing by the bed. Some are set from an app on your phone.
- Whether it starts by itself. Some clocks need a button pressed every night to start the countdown. Others run the times you set until you change them.
- Whether your child can change it. Look for a button lock, and ask whether the lock has a code. Any plug-in clock can also be unplugged.
- How bright it is at night. A clock that cannot be dimmed far enough can be the thing that wakes them. Check how many levels there are and whether the light can go off.
- Naps. A second wake time for the day, without undoing the night’s setting, saves a lot of button presses.
- Power. Mains, batteries or rechargeable. It matters for travel and for what happens after a power cut.
- What it costs to run. Most clocks are one payment. Anything with an app may have a subscription for some features, so check which ones.
The clocks UK parents ask about
Prices and facts checked on 12 November 2026 from the makers' own pages and, for the Purflo’s lights and brightness, a retailer’s. They change; check before you buy. Snoozaroo is not affiliated with any of the other makers.
| Kind | Stay in bed, then get up | Set with | Power | Maker’s price | |
|---|---|---|---|---|---|
| Tommee Tippee Groclock | Picture face | Stars count down around a sleeping owl, who wakes at the time you set | Three buttons on the clock | Mains, through a USB cable | £39.99 |
| Zazu Sam | Colour and a face | A red light with eyes closed, orange for the last half hour, then green with eyes open | The unit; its maker mentions no app | USB cable or four AA batteries | £39.99 |
| Purflo Snoozee | Colour | A red light for bedtime, a blue one for morning | The clock; its maker mentions no app | Built-in rechargeable battery | £29.00 |
| LittleHippo Mella | Colour and a face | One colour and a sleepy face, then green and a smile | The clock; its maker mentions no app | Plugs in | $64.99, shipped from the United States |
| Snoozaroo | App | A pal asleep under six stars that go out one by one, then a sunrise | Your own phone | The tablet’s charger | Free; Plus from £2.99 a month, £19.99 a year or £44.99 once |
Two notes on the table. Hatch is not in it: Hatch no longer makes the Hatch Rest, and by its own account sells the replacement in the United States and Canada (Hatch Rest alternative has the details). And the Groclock is about £25 in some shops, less than its maker’s price. Snoozaroo’s prices are set in Google Play and may change; you always see the current price before you pay.
Sleep trainer clock or children’s alarm clock?
They are different things. A children’s alarm clock wakes a child up at a set time, usually for school. A sleep trainer clock is for a younger child who wakes too early by themselves: it does not wake them, it shows them that it is not time yet. Some sleep trainer clocks have an alarm as an extra. If your child is under five and the problem is five o’clock in the morning, it is a sleep trainer clock you are looking for.
Where an app fits, and where it does not
An app is the right choice when you already have a tablet or an old phone, when you want to set the times from your own phone, and when you would like more than a clock: with Snoozaroo’s Plus plan the pal also leads the bedtime routine. It costs nothing to find out whether your child takes to it, and how the sleep clock app works shows what they would see.
An app is the wrong choice if you want no screen in the bedroom, however dim, or if you have no spare device. Then a clock or a light is the better buy, and that is a fair decision. What the screen shows at night and a tablet as a sleep clock say what is involved.
Questions
What is the best sleep trainer clock?
The one your child understands and you can live with setting. For most families that comes down to three questions from the list above: picture or colour, buttons or phone, and how dim it goes.
Do sleep trainer clocks work?
As a signal, when every grown-up keeps to it. What an OK to wake clock does, and does not has the longer answer.
Is there a sleep trainer clock with an app?
Snoozaroo is set from a phone, because it is an app. The makers of the other clocks in the table mention no app for them. Tommee Tippee also has a separate app-controlled clock, the Connected Sleep Trainer; we could not find it on sale at its UK shop or at John Lewis on 12 November 2026.
Which sleep trainer clocks can be dimmed?
Tommee Tippee gives the Groclock brightness levels from 0 to 10, and a retailer lists seven levels for the Purflo Snoozee. In Snoozaroo the brightness is yours to set, behind the grown-up PIN.
What age is a sleep trainer clock for?
It depends on the clock and the child, and makers' ages start at 12 months. For Snoozaroo we say from about two and a half. See what age an OK to wake clock works from.
Which one works for travel?
One with a battery, or an app on a phone. See a sleep clock for travel.