How we test baby monitors

Looking for a Best Buy baby monitor? Watch our video below to see the rigorous tests each baby monitor we review goes through.

Our extensive independent testing reveals which have the longest battery life and the best signal, and weeds out the baby monitors where the sound quality is so poor or the picture so fuzzy you won't be able to tell if your baby needs you or not. 

If you're worried about stories you've read about wi-fi baby monitors being hacked, you'll be relieved to hear that we test for security and privacy as well.

From Motorola to BT, find out which baby monitors are the best to buy in our baby monitor reviews. 

Which baby monitor has the best signal range? 

No matter where you live, you want a baby monitor you can rely on. We check for signal, picture and sound in these three ways.

• From room to room We test monitors by setting up the baby unit in one room with a simulated crying baby (you'll be pleased to know we don't make a real baby cry for our testing). Our experts make note of the quality of signal, picture and sound as they move away from the baby unit through three rooms, recording when the signal, picture and sound starts to deteriorate and when it's lost altogether. 
• Indoors to outdoors We take the parent-unit part of the monitor outside and walk as far as possible until the quality of reception and range declines, or is lost – useful if you have a large garden and plan to be out there while your baby takes a nap.
• In Eco mode We see if switching to Eco mode affects the reception or signal strength in any way

Best baby monitors – find out which models pass our safety and durability tests and have the best signal strength.

Is the monitor secure? 

For any smart monitors included in our tests, we provide a privacy rating. This gives you an indication of how secure the baby monitor is, based on an assessment of:

• Privacy settings.
• How complicated the security features are to set up. 
• Whether any data is encrypted or not.
• Security of any cameras and videos or images.

Will the batteries last long enough?

The last thing you want is your baby monitor running out of battery when you're in the middle of using it, and you won't want to be annoyed by the constant beep of the battery warning in the middle of the night. 

Despite what the packaging might promise, our tests often reveal that some battery-life claims are different from real life use. 

• Disposable batteries - Battery life is tested using Best Buy batteries. We'll tell you how long they’ll last before they need changing.
• Rechargeable batteries - If the monitor uses rechargeable batteries, they are fully charged in accordance with manufacturer recommendations, and our experts then work out how long they last before they need recharging.

We think a decent battery pack should last the whole evening, from baby's bedtime until you go to bed yourself – so the best baby monitors won't need to recharge their batteries until you're recharging yours.

Are the sound and picture good quality?

A baby monitor is no use if the sound and/or picture quality aren't good enough to actually use it to monitor. We put the sound and image to the test in a number of ways, so you can have confidence that your monitor will make it clear exactly when your baby needs you. 

• Quality of sound - We assess how clear and distinct the sound is, checking for any crackles, fuzziness or interference from other devices.
• Sound-sensitive lights - These lights illuminate when your baby is crying. They are useful when you want to switch off the sound or images for a short time – if you're on an important phone call for example. Our experts check that the sound-sensitive lights are accurate and increase in line with the volume output, so that you can tell the difference between sustained crying and a momentary whimper.
• Video quality - Our lab experts scrutinise the video pictures to weed out the video models that are blurred or unclear.

Is there anything else I should look out for? 

Our lab experts don't stop at testing the main features, our investigations also check how easy each baby monitor will be to use in your day to day life.

• Easy or hard to set up - We rate which baby monitors are simple to use straight from the box, including how easy the instructions are to understand and those that take time to get working.
• Stability - The last thing you want is your baby monitor toppling off a kitchen work surface as you're preparing dinner while listening out. We test how stable any docking stations are.
• Accurate temperature thermometer - Parents have raised concerns with us about the inaccuracy of the room-temperature sensors that many baby monitors have as an extra feature. We record the temperature that each baby monitor reads, alongside a calibrated thermometer. If there's a large discrepancy, we let you know in the review.
• Added extras - Our reviews document the range of helpful extra features found on each baby monitor, such as out-of-range alarms, intercom option, lullabies, paging (to help find a lost parental unit), lights that can be turned on or off remotely, or more practical aspects, such as a belt clip.

Baby monitor reviews – find out which ones are the best.

Should I buy it?

We analyse the data from our expert assessments and tests to give each baby monitor a total test score, so you can easily see the best and worst and compare different models. 

The score we give each baby monitor is made up of a combination of the elements of our tests, ignoring price, and broken down as follows: 

• Performance - 55%
• Ease of use - 30%
• Durability - 10%
• Privacy and security - 5%

To become a Which? Best Buy, an audio baby monitor must score at least 82% overall in our tests, and a video monitor must score at least 75%.

Head straight to our best baby monitors to take a look at the Best Buys.