Garmin Forerunner 255 vs Fitbit Sense

Garmin Forerunner 255 and Fitbit Sense are two smartwatches that are quite popular. Understandably, the Garmin Forerunner 255 is almost twice the price of the Fitbit Sense smartwatch. But, it does make sense to find out what are the essential differences and features of the Garmin Forerunner 255 and Fitbit Sense. We look at the key aspects of both watches below. The idea is to help you take a better decision in respect of buying your new smartwatch.

Table of Contents:

  1. Build Quality
  2. Display
  3. Battery
  4. Operating Temperature
  5. Swimming
  6. Android and iPhone support
  7. Device Storage
  8. Music
  9. Wireless Connectivity
  10. ECG
  11. Multi-frequency positioning
  12. Software
  13. Incident Detection
  14. Costs
  15. Summary

Build Quality

The build quality of Forerunner 255 is solid in comparison to the Fitbit Sense. It has a fiber-enforced polymer body. Fitbit Sense is made of a aluminum bezel and the body is made of an elastomer material.


The lens material on Forerunner 255 and Fitbit Sense are made of Corning Gorilla Glass 3. However, the Forerunner 255 has a memory in pixel or MIP screen. Fitbit Sense uses an AMOLED screen. AMOLED screens have a better display and contrast ratio.

  • Fitbit Sense has a better display resolution of 336 x 336 pixels.
  • In comparison, the Forerunner 255 has a display resolution of 260 x 260 pixels.
  • The display screen of Fitbit Sense is larger than the display size of Forerunner 255. Fitbit Sense has a 1.58″ display and Forerunner 255 has a 1.3″ display screen.
  • Fitbit Sense has a more contemporary box look. Forerunner 255, on the other hand, has a round shape that is more akin to the standard Garmin smartwatch shape.
  • Fitbit Sense has a better pixel density of 301 ppi and Garmin Forerunner 255 has a pixel density of 282 ppi. The depth of display depends upon the pixel density of the screen.
  • Fitbit Sense comes with the touchscreen feature while the Garmin Forerunner 255 does not have the touchscreen functionality.


In terms of battery backup, the Forerunner 255 watch can last for up to 14 days on the smartwatch mode. On the GPS mode, a Forerunner 255 can easily last for up to 30 hours.

Fitbit Sense can last for up to 6 days on full battery backup. On the GPS mode, it can last for a maximum duration of 12 hours. The nice thing about Fitbit Sense is that it supports fast charging. It adds a day worth of battery backup in 12 minutes of fast charging. So, you are never out of business with a Fitbit Sense.


Operating Temperature

One of the key strong points of the Forerunner 255 is the operating temperature range. It can support high temperatures up to 60 degree Celsius. Fitbit Sense has a maximum high temperature limit of 45 degrees Celsius.

It remains to be seen if the Fitbit Sense’s working gets jeopardized in hot conditions. Especially, when you are using the Fitbit Sense outdoor during bright sunny days.


Garmin Forerunner 255 carries a water resistance rating of 5 ATM and this makes the watch ideal for swimming up to a depth of 50 meters or 165 feet below water surface level. There have been no known issues of water seeping through the Forerunner 255 watch. The water-seal is robust. Forerunner 255 is suitable for pool water swimming and open water swimming. The watch comes with in-built profiles for pool water and open water swimming.

Forerunner 255 must not be used for deep sea diving or snorkeling.

Fitbit Sense is also rated for swimming up to 50 meters below water surface level. General user feedback, however, suggests that the Fitbit Sense does not like exposure to water. You need to be very wary of wearing one while swimming.

Android and iPhone support

Forerunner 255 and Fitbit Sense can work well with Android and iOS operating systems. So, if you have an iPhone or an Android phone, you could pair these with the Forerunner 255 and Fitbit Sense devices for a flawless working.

Fitbit uses its Fitbit app to link the smartphone with the Fitbit Sense smartwatch. Garmin uses the Garmin Connect app to link the smartphone with the Forerunner 255 smartwatch. The Fitbit app and Garmin Connect app are developed and updated for the Android and iOS operating systems.

Device Storage

Forerunner 255 has an internal device storage of 4 GB. This space is used for providing maps coverage to the Forerunner 255 watch wearer. Fitbit Sense also comes with 4 GB internal device storage. Out of this, you can use around 2.5 GB is available space for storing music playlists of Deezer or Pandora.


Forerunner 255 standard edition watch does not have music feature. You cannot store audio content on the Forerunner 255. And, you cannot use the standard edition of Forerunner 255 to control smartphone music. If you intend to use music, you will need to buy the Forerunner 255 Music edition. The music edition of Forerunner 255 allows you to store offline audio content and manage the smartphone music through the watch.

Fitbit Sense does not have offline music storage. However, it does allow you to import the Deezer or Pandora playlists for offline listening through the Deezer or Pandora apps. A valid subscription to Deezer or Pandora is needed to import your playlists on to the device storage of Fitbit Sense. You cannot download your personal audio content on the Fitbit Sense.

Wireless Connectivity

Forerunner 255 has ANT+ and Bluetooth connectivity. ANT+ can be used for broadcasting heart rate data to eligible devices. On a similar basis, Forerunner 255 can make use of ANT+ for relaying data to other ANT+ capable devices. However, Forerunner 255 does not support Wi-Fi networks.

Fitbit Sense supports Bluetooth and Wi-Fi. It cannot, however, support the ANT+ wireless protocol.


Forerunner 255 does not support ECG functionality. Fitbit Sense comes with an ECG feature that can be used to take spot readings of the ECG for your heart. The ECG app can be used to take ECG readings. You can share the results with your medical practitioner. This could, potentially, help in detecting conditions of A-Fib.

Both watches can track heart data very closely. Forerunner 255 shares heart rate data during activities as well. Fitbit Sense and Forerunner 255 can also share heart rate alerts when the heart rate goes under or above the pre-defined heart rate range.


Multi-frequency positioning

Forerunner 255 is designed for advanced runners. It comes with a multi-frequency positioning sensor that allows you to make use of multi-band frequency. You can take GPS coordinates from multiple satellite systems at the same time. This improves the accuracy of GPS data. Fitbit Sense does not support multi-band frequency at this point of time.

For someone who is wary of GPS accuracy for outdoor runs, a Garmin Forerunner 255 is way ahead of the Fitbit Sense. If you are a runner, there can be no match for the Forerunner 255 or the Forerunner series smartwatches.


Forerunner 255 is based on the Garmin operating system and the Fitbit Sense is based on the Fitbit operating system. Forerunner 255 carries an operating system that is bundled with advanced training and activity tracking software. There are in-built software modules for providing valuable insights on your outdoor runs.

On a similar basis, there are pre-built modules for swimming and cycling activities as well. You will notice that the Forerunner 255 has a very high level of activity tracking details that capture every aspect of your run, swimming, or cycling activities. In comparison, a Fitbit Sense is more like a generalized smartwatch.

Incident Detection

Forerunner 255 comes with an incident detection feature. The incident detection feature is available for selected activities only. Upon detecting an incident, the Forerunner 255 watch will wait for a response from the wearer. If it does not get a response, it will share the GPS data of the wearer with the designated emergency contacts. The incident detection feature of Forerunner 255 is more like the fall detection feature of Apple watches.

Fitbit Sense does not have any fall detection or incident detection feature.


Forerunner 255 is priced at $399 and the Fitbit Sense is a little over $200 with a 6 month Fitbit premium subscription included in the price. The price difference is substantial. But, the Forerunner 255 is the watch for runners and athletes. Your goals would define which watch suits your purpose.


Forerunner 255 is more suitable for runners. If your training and running data is of paramount concern, the Forerunner 255 watch is the ideal fit. It will provide you extensive and in-depth data about the running data.

Fitbit Sense is more like a generic watch with good set of health tracking features. It ticks most boxes for all-round smartwatch wearing through the day.

You may also like to read more content related to Garmin Forerunner and Fitbit Sense below:

Helen Kurt - Contributor on TECHEPAGES.COM. Reach me on email.

Helen Kurt is a geeky nerd who loves to cover the wearables space. She has over 5 years of experience in the smartwatch domain. You can reach her on email at [email protected].