HR Graph HR Graph

Graph your Heart Rate on the watch display

This App displays readings from the Heart Rate sensor and plots them on a graph. The display timout is turned off while the app is running to keep the display on.

Designed for monitoring your heart rate on the watch during heart rate focused activities such as intensive interval training. Can also be used during meditation to occasionally check heart rate with minimal effort.


  • Display timeout is re-enabled when battery level falls below 20% to save power if accidentally left on

  • Shows the update rate from the Heart Rate sensor

  • Heart Rate display and Graph drawing colour changes to gray if heart rate update is over 3 seconds old

  • Each Horizontal display pixel represents 1 second

  • Each Vertical display pixel represents 1 bpm

  • The Graph Heart Rate scale is from 40bpm to 200bpm

  • The Graph Time scale is 327 seconds on the Ionic and 279 seconds the Versa due to the different screen sizes

  • Timer shows how long the Graph has been running

  • Lower right button pauses/unpauses the Graph and Timer

  • Upper right button resets the Timer and Graph

  • Left button exits the app with a confirmation dialog

  • Screen touches are disabled to prevent accidental activation of pause or reset by fingers or water, such as while swimming etc.

  • The Graph rolls over back to the start once it reaches the end of the screen, the Timer continues

  • Uses around 5% to 10% battery per hour depending on screen brightness


The Heart Rate data is provided to the app by the Fitbit OS, it is the same data that is shown in the built-in apps on the device.

The accuracy of optical Heart Rate sensors are known to be affected by water, so if you intend to try this in the pool, make sure the watch is tight on your wrist. You will need to take the strap down a notch or 2 until it is not possible to slide the watch up and down on your wrist when placed in the water. If the watch is not worn tightly enough the heart rate sensor can read significantly under your real heartrate. If worn tight enough, testing has shown it to be fairly accurate although this may vary from person to person. Check it after a few sprints by using the clock and feeling your pulse.


This app does not store, use or save any data to your Fitbit account or any other service or server. Heart Rate data is only displayed on the screen and is lost when reset button is pressed or the app is closed.


Fitbit OS 2.0 has a new feature where the display is turned off when the screen is splashed or submerged in water. Touching the screen with a thumb, several fingers or the palm of the hand also turns the screen off. To overcome this feature and allow the screen to be always on, if the App detects that the screen has been turned off, the screen is immediately turned back on unless a low battery condition is detected (battery below 20%). If the screen turns off due to a low battery condition, the graph is also paused.


If you have any questions, suggestions / feature requests, or issues with the app please email:

To help motivate further development of this App, please indicate if you have installed it on your Fitbit, click either the "Installed on Ionic" or "Installed on Versa" Button depending on your device.
We ask this because the Fitbit App Gallery does not provide any statistics for developers or users on the number of app installs, making it difficult for developers to justify spending time on further developments.
Total installs: 195