How do video doorbells work?

How do video doorbells work
(Image credit: Ring)

Are you constantly missing deliveries because you’re out? Or maybe you’re fed up of being caught out by cold callers, and want a way of checking who’s at the door before you open it? You’ve probably heard that the best video doorbells are a handy solution, letting you converse with anyone on your doorstep from your smartphone.

However, if you’re not entirely sure how these handy smart home gadgets actually work, we’ll explain exactly how video doorbells work, where they store the video they record and how they can be integrated with the best smart home devices to automate your home. 

Want to get your hands on a video doorbell now? Check out these great deals for some of the best on the market, although we might some big deals also appear whenever Prime Day 2021 rolls around:  

As well as letting you see and speak to whoever’s on your threshold if the doorbell is pressed (thanks to a built-in camera, microphone and speaker) smart doorbells will also act in the same way as the best home security cameras

They’ll alert you if motion is detected in its field of view, so you’ll know if there’s any unwanted visitors to your property. They’ll even store the footage so you can go back and review it at a later date, providing peace of mind that your home is safe if you’re away for a few days or weeks.

Video doorbells have surged in popularity over the past four years, with one in four homes in the US owning one, according to research firm Strategy Analytics, and it’s not surprising as they really do make life a little easier. 

Some are battery powered and can be installed with very little DIY expertise, such as the Ring Video Doorbell 3 Plus, while others, like the Arlo Video Doorbell are designed to replace an existing wired doorbell, and may require professional installation. 

Some video doorbells even use artificial intelligence (AI )to identify whether it’s a person, animal or vehicle they’ve detected to prevent you getting notified every time a bush mildly wobbles in the wind.

It’s worth keeping in mind though, that most video doorbells require a monthly subscription to get the most out of them. This enables you to review footage after it’s happened, as well as access the smart features and functions designed to reduce unwanted alerts such as setting activity zones so you’re only alerted about motion in these areas of the camera’s field of view.

video doorbell

(Image credit: Arlo)

How do video doorbells work?

Video doorbells work in the same way as the best home security cameras; by using Wi-Fi to send a notification to your phone whenever motion is detected in the doorbell’s field of view, or the doorbell itself is pressed. 

If you receive a notification, or you just want to see what’s happening at your home, you can use the companion app on your smartphone or table (or get a dedicated smart display) to log in to the doorbell’s camera and see who’s on your doorstep. 

The doorbell’s built-in speaker and microphone allow you to converse with anyone in the camera’s field of view too. 

Video doorbells also store the footage recorded when motion is detected or the doorbell is pressed so it can be reviewed back at a later date. This is handy if you couldn’t answer the alert at the time it arrived, but want to see who the caller was. 

However, as we’ve already mentioned for many video doorbells, this does require a monthly subscription, which starts from $2.99 / £2.49 / AU$4.49 . 

The Eufy Video Doorbell 2K is one of the few smart doorbells that doesn’t need a subscription, instead up to 16GB of video  - around two week’s worth - can be stored on the bundled base station, so there’s no on-going cost.

Unwanted notifications about motion that turn about to be birds, the wind rustling through trees or pedestrians on the pavement can be frustrating, so many video doorbells also offer handy features to reduce these nuisance alerts; for example activity zones so you’re only alerted when motion is detected in these areas and AI that can identify whether an animal, vehicle or person caused the alert too. 

Most video doorbells also offer integration with Amazon Alexa, Google Assistant or HomeKit, so they can be set to work with your smart speakers and smart displays; making a sound when the doorbell is pressed and letting you converse with whoever is on your doorstep. 

In the case of smart displays, they can be used to view the doorbell’s feed too. Not all video doorbells work with all voice assistants, however, so make sure you check it will work with your current kit before you buy.  

Which are the best video doorbells? 

The video doorbell market is a crowded one with big names in home security including Ring, and Arlo competing alongside the likes of Google and Eufy. Some brands even offer a choice of models to choose from. We’ve rounded up out pick from each of the big hitters to help you choose.  

Arlo Video Doorbell

(Image credit: Arlo)

Arlo Video Doorbell Wired

Best wired video doorbell

Specifications

Resolution: 1536 x 1536
Footage recording: Unlimited video for up to 30 days with subscription
Audio: Two-way
Power: Mains

Reasons to buy

+
Detailed clear video
+
1:1 aspect ratio s 
+
Support for Alexa, Google Assistant and HomeKit

Reasons to avoid

-
Limited features without subscription
-
Complicated installation

In our eyes this is the best video doorbell you can buy, as it offers detailed video that lets you see the full length of anyone on your doorstep, support for all the major smart home platforms and even lets people leave a message for you if you can’t get to the door. However most of the features rely on subscribing to Arlo’s monthly services. Arlo also offers a battery-powered version, although that currently doesn’t have HomeKit support.  

Ring Video Doorbell 4

(Image credit: Ring)

Ring Video Doorbell 4

Best battery-powered video doorbell

Specifications

Resolution: 1920 x 1080
Footage recording: Unlimited video for up to 30 days with subscription
Audio: Two-way
Power: Battery

Reasons to buy

+
Clear video and audio
+
Can be battery-powered or wired
+
Pre-roll feature 

Reasons to avoid

-
Limited features without subscription
-
Lacks Google and HomeKit integration

Video doorbell giant Ring offers a host of different models, some of which are battery-operated while others are mains-powered. All of them make conversing with anyone on your doorstep simple, but it’s newest video doorbell looks set to be the best battery-powered offering yet. It offers detailed footage, including a color pre-roll feature that stores the four seconds of video before motion is detected so you have a clear pic, along with clear audio. On top of that, the battery is removable, so if you purchase additional batteries, it won’t be out of action when the battery runs out. 

Nest Hello

(Image credit: TechRadar)

Nest Hello

Best video doorbell with facial recognition

Specifications

Resolution: 1600 x 1200
Footage Recording: Unlimited video for up to 60 days with subscription
Audio: HD two-way
Power: Mains

Reasons to buy

+
Useful face recognition
+
Easy-to-use app
+
Clear video and audio

Reasons to avoid

-
Subscription required for full features
-
Limited Alexa integration and no support from HomeKit

Google only offers one model of video doorbell at the moment, but it’s got something no other smart doorbell on the market has - facial recognition. It’ll captures the face of anyone approach the door and allow you to assign a name in the app. Next time they visit, the app will offer up a notification identifying them. It improves over time too. However, you do need a monthly subscription to get the most out of this doorbell and it only has limited Alexa integration, and no support for HomeKit at all, so is best suited to those that are properly embedded in the Google ecosystem. 

Eufy Video Doobrell 2k (wireless)

(Image credit: Eufy)

Eufy Video Doorbell 2K (wireless)

Best video doorbell without a subscription

Specifications

Resolution: 2048 ×1080
Footage recording: 6GB of free local storage on base station
Audio: Two-way
Power: Battery

Reasons to buy

+
No monthly subscription required
+
Detailed 2K video
+
Simple installation

Reasons to avoid

-
Delay in voice chat and video
-
Footage in bright scenes lacks detail
-
Some downtime to recharge

Eufy also offers a mains powered version of this doorbell, alongside a Full HD battery-operated model, but the Eufy Video Doorbell 2K represents the best value. Unlike other video doorbells we’ve tested, it doesn’t require a subscription as the detailed 2K video is stored on a base station that sits in your home. As it’s battery-powered, it’s best suited to renters or anyone without a wired doorbell. However, the doorbell will be out of action when it needs charging and we did find some delay when conversing with people on our doorstep.

Do video doorbells get stolen? 

Like any item on the exterior of your property, there is a small possibility it could be stolen. Most video doorbells require screwing to the exterior of your property, so it certainly won’t be an easy task for them to be removed, but it could happen. 

Ring video doorbells come with a security screw, which can only be removed by a unique type of screwdriver (included in the box) that can deter thieves. Ring also promises to replace any of its video doorbells that are stolen providing you contact them within 30 days of theft and provide the police report.  

Carrie-Ann Skinner

Carrie-Ann Skinner was formerly Homes Editor at TechRadar, and has more than two decades of experience in both online and print journalism, with 13 years of that spent covering all-things tech. Carrie specializes in smart home devices such as smart plugs and smart lights, as well as large and small appliances including vacuum cleaners, air fryers, stand mixers, and coffee machines. Carrie is now a copy editor at PWC.