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How to enable AFib monitoring on Fitbit and why you should

Get notified when your heart beats out of step.
June 6, 2023
Fitbit Sense 2 Review Heart Rate Graph
C. Scott Brown / Android Authority

Most of the best Fitbit trackers feature accurate heart rate monitors. These little sensors provide valuable insight into our ticker’s rhythm when resting or on the go, but heart rate alone is only a tiny snapshot of our overall heart health. Fitbit recently added atrial fibrillation (AFib) notifications and irregular heart rhythm monitoring to a select number of its devices. But what is AFib, why is it important, and how can you use your Fitbit device to monitor for instances of it?


To activate irregular heart rhythm notifications on Fitbit, open the app, select the Discover tab, then tap Assessments & Reports > Irregular Rhythm Notifications > Set Up Now. Follow the prompts to complete the setup.


What is AFib?

In the simplest terms, atrial fibrillation, shortened to AFib, occurs when the heart’s upper sections beat at different rhythms, resulting in a quickened, irregular heart rate. According to Mayo Clinic, this condition could also result in shortness of breath, poor blood flow, and blood clots in the heart. AFib also increases the risk of a stroke. For this reason, users susceptible to AFib should use a heart rate monitor that can detect these abnormalities.

How does Fitbit’s AFib monitoring work?

A Fitbit Charge 5 displays a user's heart rate.
C. Scott Brown / Android Authority

Fitbit devices don’t have any dedicated AFib sensors onboard. Instead, they use their heart rate (PPG) sensors to keep track of your pulse rhythm. Viable data is collected over time and analyzed to provide a baseline heart rhythm. Fitbit can then compare this baseline to beat-by-beat measurements, and alert users if it notices a large enough discrepancy. For context, Fitbit suggests a 10bpm increase in a short period of time might be enough to be considered irregular, but this data threshold will vary from person to person.

Importantly, Fitbit mentions that its irregular heart rhythm feature doesn’t “continuously” monitor for AFib, nor does it issue immediate alerts for instances of AFib. Fitbit also cautions that they may miss some cases of AFib. Additionally, only pulse rate data acquired when you’re still is used to inform the AFib monitoring system. This means it’s more important than ever to wear your Fitbit to bed if you want accurate results.

How do Fitbit’s ECG and irregular heart rhythm monitoring features differ?

fitbit sense review heart rate sensor
Jimmy Westenberg / Android Authority

While ECG and irregular heart rate monitoring both paint a picture of a user’s heart rate health, the two feature’s processes are entirely different.

The ECG (electrocardiogram) sensors on the Fitbit Charge 5, Fitbit Sense, and Sense 2 use electrical signals to survey a user’s heart performance in 30-second intervals. To get an ECG reading on these devices, users are required to initiate the process, and the resultant data is presented in a detailed PDF. A doctor can use the data acquired by the ECG to detect possible signs of AFib, but as it’s a spot check, this data can only ever be used retroactively.

Fitbit’s irregular heart rhythm monitoring system uses long-term pulse data and compares it to recent heart rate patterns. Once enabled by the user, this process automatically runs in the background and monitors a user’s heart rate when they are at rest. The irregular heart rhythm system will notify users of possible AFib instances recorded in the last 24 hours. While this isn’t a real-time solution to AFib monitoring, the irregular heart rhythm system benefits from being largely automated.

Which Fitbit devices feature AFib monitoring?

fitbit versa 2 heart rate
Andy Walker / Android Authority

In April 2022, Fitbit announced plans to roll out irregular heart rhythm monitoring smarts to several of its devices. At present, 12 of its smartwatches and trackers are supported. Impressively, it’s not just the company’s latest smartwatches and trackers that gain the feature. As the feature can utilize older sensors, the Fitbit Charge 3 and Versa Lite are included on the supported list. Cheaper devices, like the Inspire 3, also make the feature more accessible.

Fitbit devices with irregular heart rhythm monitoring

  • Sense 2 (includes ECG sensor)
  • Sense (includes ECG sensor)
  • Versa 4
  • Versa 3
  • Versa 2
  • Versa Lite
  • Charge 5 (includes ECG sensor)
  • Charge 4
  • Charge 3
  • Luxe
  • Inspire 3
  • Inspire 2

While the Google Pixel Watch relies on Fitbit’s fitness and health monitoring software and possesses an ECG sensor, it does not have irregular heart rhythm monitoring features.

How do I enable AFib monitoring on Fitbit?

To keep tabs on possible instances of AFib, you’ll need to enable irregular heart rhythm monitoring on your Fitbit.

fitbit irregular heart rhythm notification 1
  1. Open your Fitbit app.
  2. Open the Discover tab.
  3. Tap the Assessments & Reports section.
  4. Tap the Irregular Rhythm Notifications icon.
  5. Select Set Up Now, and follow the prompts.

You can also view historical data by tapping the Irregular Rhythm Notifications tile. If an instance of AFib is detected, you’ll also receive a notification at the top of the Fitbit app.

Fitbit irregular heart rhythm monitoring feature is only available in a select number of countries, but more regions will be added as local clearance is obtained.

How to disable Fitbit irregular heart rhythm monitoring

  1. Tap your profile image on the Today tab within the Fitbit app.
  2. Head to the Activity & Wellness section.
  3. Tap Heart Settings > Irregular Rhythm.
  4. Tap Turn off this feature and select Turn off.


Yes. The FDA cleared both Fitbit’s irregular heart rhythm and ECG systems.

According to a study conducted by the company, Fitbit devices were able to correctly identify AFib episodes 98% of the time.

You should consider contacting your doctor should Fitbit’s irregular heart rhythm system issue an alert.

Yes, the Fitbit Charge 5 can detect irregular heart rhythm. It also features an ECG sensor.