Connected watches – or smart watches – are now an integral part of our daily lives. True extensions of our faithful smartphones, these high-tech timepieces are becoming increasingly sophisticated, with manufacturers vying for ingenuity to stand out. Here are the main criteria to check before buying a digital smart watch.

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Smart watches run on batteries, like smartphones. They must therefore be recharged regularly. Their autonomy depends on the capacity of the battery, but also on the technology of the screen. As a result, it varies greatly from one model to another. According to our laboratory measurements, they offer an autonomy of between 2 and 16 days depending on the model. This autonomy varies, of course, depending on the intensity of your use of the watch. Our laboratory tests will allow you to choose a watch that does not require daily recharging.

Smart watches with GPS navigation

On a connected watch, GPS is not only used for navigation. It is thanks to this chip that the watch can record your routes when walking, cycling or running outdoors. Using it puts a lot of strain on the battery.

Connected watches with 4G technologie

Some smart timepieces include a connection to 4G mobile networks. Thanks to the built-in microphone and speakers, you can make phone calls. You will also receive notifications from your smartphone (messages, social networks, etc.) even if it is not nearby. The connection is made possible by the presence in the watch of a virtual SIM card associated with the same subscription as the smartphone. Today, only Orange offers this option for compatible Apple Watch and Galaxy Watch. All you have to do is subscribe to the multi-SIM option for €5/month after activating the virtual SIM card (this operation costs €10).

Heart rate monitor

It allows you to take your pulse and measure your heart activity during and after a physical activity (recovery after exercise).

ECG function

Apple inaugurated this function on the Series 4, which has since been adopted by Samsung (Galaxy Watch Active 2 and later) and Withings (Move ECG). An ECG watch (electrocardiogram) is able to monitor your heart throughout the day and warn you in case of abnormality. However, this function cannot replace a real medical examination if necessary!


Most Smart watches are waterproof. But remember to take it off when you go swimming in the sea: they can withstand the chlorine in swimming pools, but not the salt.

Wireless charging

Many models come with a dedicated charger, but wireless charging, which allows you to recharge the battery by simply placing the watch on a charging mat, is becoming more common. This is good news, as this feature is very convenient in all iphones and smart timepieces.

Which watch to choose according to my use?

Having a budget is good. But it is important to think about your uses. Are you an accomplished sportsman? Do you want a discreet watch that relays a few notifications and wakes you up in the morning?

It is important to think about what you want to do with your future connected watch. Manufacturers tend to focus on one area at a time: sports or utility. There are few smart timepieces that do everything.