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Apple Watch Green Light On? Explained

Last Updated Nov 18, 2022
apple watch

Apple watches are easily the most popular smart watch and, although they are fairly easy for users to understand, it can be confusing to decode the lights that flash occasionally. For example, you may have noticed green lights appearing on the back of your watch, but what does it mean?

The green lights on your Apple watch indicate that it is tracking your heart rate. This works by the Apple watch detecting your blood flow as you wear it.

This is a useful tool for people who work out or who simply want to keep tabs on their heart. Keep reading to find out more about this feature and other useful tools on your Apple watch

Why Are There Flashing Green Lights On My Apple Watch?

There are many different reasons why your Apple watch may be flashing green lights, because it is detecting your heart rate.

One reason that the green lights may come on is due to your heart rate elevating, like during a workout. When you stop working out and your heart rate drops, the lights will turn off automatically. 

But how is it possible for your Apple watch to detect your heart rate? Let’s find out below.

How Can My Apple Watch Detect My Heart Rate?

The green lights don’t just let you know that your watch is gathering data. They also serve a key function in reading your heart rate. 

The science behind your watch being able to read your heart rate is pretty cool.

Blood absorbs green light and your watch has light-sensitive photodiodes which allows it to measure how much light your blood is picking up on. More blood flow means that more light is absorbed, which consequently means you have a higher heart rate, like when you are working out.

This feature is especially great if you have chronic conditions and need to monitor your heart rate regularly, or even if you’re just health conscious.

Now, let’s see why the green lights on your Apple watch are flashing when you’re not even wearing it.

Why Are Green Lights Flashing When I’m Not Wearing My Watch?

You may have noticed green lights flashing on the underside of your apple watch even when you’re not wearing it. 

Since the green lights mean it is detecting your heart rate, why would they flash when you are not wearing it? While this may seem confusing at first, it has a pretty simple explanation. 

Because your watch periodically senses your heart rate, it’s possible that you might take it off while it is in the middle of detecting it. This means that you might see those green lights even when you are not wearing your watch.

The lights will typically only stay on for a couple of minutes and then will automatically turn off, so you should not worry about having to manually turn them off.

How to Turn Off the Green Lights on Apple Watch

However, if you aren’t a fan of the green lights flashing or are simply not a fan, there are a couple ways to permanently turn them off.

The most permanent solution would be to disable the heart rate monitor. To do this:

  1. Go to your Apple Watch’s Settings app
  2. Navigate to ‘Privacy,’ 
  3. Navigate to ‘Health.’
  4. Click on ‘Heart Rate’
  5. Disable the feature

If you ever change your mind and would like the feature back, simply follow the same process to re-enable it. The feature is extremely helpful and there are very few reasons to disable it. 

What Do Other Lights Mean On My Apple Watch?

Now that we’ve explained what the green lights mean, you may be wondering about the other lights that show up on your apple watch. 

Here are the meanings of some other lights that you may notice from your watch:

  • Green lightning bolt:  This light means that your watch is charging successfully. 
  • Red lightning bolt: This means that your watch is on low battery and it is time for you to charge it. 
  •  Yellow circle: The watch is in low power mode in order to prolong the battery. You can easily switch out of this mode by going to the settings.
  • Red lights on the bottom:  If your watch is flashing red lights as opposed to green it means that it is detecting your blood oxygen levels. The lights are able to detect how bright or dark your blood is. Brighter blood means you have more oxygen and vice versa.

This list will give you a great starting point for understanding your Apple watch. 


We hope this extensive explanation gives you some good information on your Apple watch and what its lights mean. 

Apple watches have one of the most user friendly interfaces and are incredibly popular. Its health features, like the heart rate and blood oxygen detection, are things that give us great insight into our health. 

Hopefully you are now able to use all of its features with ease.