The 4 best silent alarm clocks of , tested and reviewed

If you want a completely silent wake-up, the Philips SmartSleep Wake-Up could be perfect for you. Before your alarm is scheduled to go off, it dimly lights up and then gradually brightens as your wake-up time approaches. It offers impressive sunrise and sunset simulations with peaceful natural sound options, including birds, ocean waves, and Nepal bowls — or you can choose to wake up to your favorite FM radio station.

The light intensity is adjustable, with up to 20 levels to choose from, so you can set it just right whether you're a light or deep sleeper. The display automatically dims as the room darkens, keeping your bedroom cozy and free from distractions. The snooze function is simple to use, too — just tap anywhere on the device to get a few more minutes of rest.

During testing, the Philips SmartSleep Wake-Up light woke me up gently, and I consistently felt refreshed. It even doubles as a neat, sleek, and stylish bedside lamp. It's a great choice for those searching for a natural, gentler way to wake up without complicated tech or apps.

See more wake-up light options in our guide to the best sunrise alarm clocks.

For a reliable, difficult-to-ignore, and nearly silent alarm, a wearable is the way to go. Usually, I wear an Apple Watch and am consistently awoken when it vibrates on my wrist when the alarm goes off. 

But my Apple Watch battery only lasts around 18 hours, and not everyone remembers to charge their watch every night before bed. Many of the best Fitbit models can go about a week before you need to plug it in, and they offer a vibrating alarm clock feature, too. Plus, many Fitbit models are at least $100 less than an Apple Watch. The Fitbit Sense 2 is our best smartwatch for sleep-tracking.

You can set up to eight alarms right on the device and choose each day you want it to go off. Fitbit offers two vibration settings, light and heavy. The buzzing is insistent, but I wish it was even stronger. I still never slept through it. It only vibrates for about 15 seconds before automatically snoozing for 9 minutes, and there isn't a way to change either duration. It would be nice if there was a bit more personalization, like if I could set a vibrating pattern or adjust the intensity apart from the general notification vibrations. 

Because the Sense is also a sleep tracker, it monitors when you go to bed and gets up and provides you with a sleep score. It also includes built-in skin temperature sensors, ECG readings, and real-time stress tracking to give you a robust look into your vitals.

There's an optional "smart wake" feature on the alarm that detects when you're in a lighter stage of your sleep cycle and wakes you up to 30 minutes before your alarm is scheduled to go off. This is supposed to make you feel less groggy than if you woke from a deeper sleep. 

If you don't need as many bells and whistles, the brand's other wearables have similar vibrating alarms. The Fitbit Inspire 3 is a great budget option.

Read our full Fitbit Sense 2 review.  

Despite the name, the Sonic Bomb Extra-Loud Alarm Clock doesn't solely rely on sound to wake you up. Put the puck-like shaker under your mattress, and the vibration will almost certainly jolt you awake. 

It's not exactly a pleasant way to wake up, and the vibration isn't silent either. But for people who are deaf or hard of hearing, a physical alarm that isn't sound-based could be useful if a light-based alarm isn't reliable enough. 

If you sleep with a partner in your bed, there's a good chance this alarm will wake them up too. Even with a very thick mattress, I could feel the alarm buzzing from the other side of the bed. The resulting sound wasn't very muffled, either. 

I liked that this alarm was pretty customizable for the price. You can wake up with just the vibration or a buzzing sound or combine them. The tone of the buzzer can be changed, and you can opt to turn the flashing lights on or off. 

I was also impressed by the customizable snooze functionality. The ability to change the duration isn't something you always find on budget-friendly alarm clocks. 

While there are two alarms, you have to remember to toggle between them if you don't want your weekday alarm going off on Saturdays, though you can choose to have both go off every day. 

For those who like to fall asleep to music or podcasts and wake up with sound cues, a comfortable pair of sleep headphones can be a great solution. AcousticSheep's SleepPhones are breathable and washable and can last days without needing to be charged. 

I listen to audiobooks to fall asleep, and it was nice knowing that my alarm would play through the headphones in the morning. After the alarm went off, I invariably left the headphones on and paired them to my phone by accident. Yet they lasted well over a week without me needing to charge them.

When I did need to charge the headphones, I pulled the module out of a pouch in the headband. You can wash the SleepPhones, but you need to remove all the components first. Unlike some sleep headphones I tried, the pouch concealed any blinking light you sometimes get with Bluetooth devices. 

However, I did need to download a third-party alarm app. This was true of every pair of headphones I tried. Even if they were connected to my iPhone, the native alarm app would play through the phone's speakers instead of to my headphones. That really defeats the purpose if you're trying not to wake anyone else up. 

The SleepPhones are available in fleece or a more breathable fabric that reminded me of workout shorts. While the bands come in three sizes, I couldn't adjust the size, which was a problem. The medium sometimes felt too constricting when I was trying to sleep. 

In addition to getting insight from Kelly Waters, MD, a sleep specialist at Spectrum Health, I tested seven different silent alarm clocks and evaluated them based on the following criteria: 

Setup: For each alarm, I tried to set it up without reading the instructions to see how intuitive they were. I then set them up again after reading the manual to make sure the directions were easy to follow.  

Performance: I used each alarm for at least three nights. I evaluated how easy it was to set the alarms, whether they consistently woke me up, and how difficult it was to shut off and snooze them. For at least one night, I put the alarm on my partner's side of the bed or had him use it so I could see if I was disturbed when he woke up. 

Special features: I tested features such as Bluetooth or WiFi connectivity, accompanying mobile apps, wind-down programs, and night lights to see if they were helpful and simple to use. 

Durability: To test how breakable each alarm clock was, I pushed each off my nightstand. They all passed this test, though the Mesqool's battery cover did pop off. (I was able to put it back on.) 

Long-term use: After testing, I'm continuing to use our top picks to monitor for durability and usability.

What is a silent alarm clock? 

There are two ways to look at it: It's either something like a wake-up light that makes no noise, or it's something like a vibrating alarm that, while not necessarily silent, can wake up someone who can't hear a sound-based alarm.

How do silent alarm clocks work? 

"Even in sleep, the brain is still processing your environment," Kelly Waters, MD, a sleep specialist at Spectrum Health, told Business Insider Reviews in an email. "Any abrupt change to that stasis will elicit a response, whether the abrupt noise of an alarm, vibration, movement, or light." However, she said not everyone responds to the same type of wake-up cue.

How do sunrise or wake-up light alarm clocks work? 

"These rely on the natural waking response to ambient light," said Waters. "The brain will be susceptible to waking when it is naturally in lighter sleep." She warns that these aren't precise and may not work for everyone, including heavy sleepers.