Fitbit quietly added new feature that the Apple Watch doesn't have

Fitbit has quietly enabled blood oxygen monitoring on some of its devices, a feature that could help users spot changes in breathing as they sleep. Fitbit device owners on Reddit first noticed the change, and the company has since confirmed the update to Business Insider and several other outlets.

Fitbit's line of Versa smartwatches, its Ionic sports watch, and the Charge 3 wristband have always included hardware that's capable of estimating the variability of oxygen levels in the blood. But the company only began activating this feature last week by rolling out a graph visible in the Fitbit app, displaying how the oxygen level in a user's bloodstream varies during sleep.

The company said it began providing the feature to a small number of users, but that all Fitbit owners with a device that supports blood oxygen monitoring would be able to access these statistics by the end of the month. Fitbit also isn't the only one to add blood oxygen monitoring to its devices; companies such as Garmin and Withings offer this feature as well. 

The addition of blood oxygen monitoring could help Fitbit further distinguish itself from Apple, which is currently the worldwide leader in wearable technology device sales. The Apple Watch doesn't support this blood oxygen measuring feature, but the Series 5 model does have a few health-oriented capabilities that Fitbit lacks.

Such features include the ability to take an electrocardiogram, detect when the wearer has taken a hard fall, and notify users if they're being exposed to high sound levels for prolonged periods of time.

This new update is the latest in the competition between Fitbit, which Google acquired in November, and Apple to bring more health-focused features to their wearable devices. Apple accounted for 35% of the global wearable technology market as of the third quarter of 2019, followed by Xiaomi, Samsung, and Huawei, according to the International Data Corporation. Fitbit, comparatively, accounted for just 4.1% of the market during the same time period. 

Although Apple does offer a few features not found on Fitbit devices, the now-Google-owned health tech company does track one area that the Apple Watch is currently missing: sleep monitoring. Fitbit devices are capable of monitoring sleep by default, enabling them to provide statistics on how long you've slept and how much time you've spent in specific stages of slumber.

The Apple Watch doesn't monitor sleep natively and instead requires wearers to download a third-party app. That could change this year. According to Bloomberg, Apple is testing sleep tracking for its future watches.