Fitbit Flex 2 Review | 171 Data compared

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  • Avg. price in UK: ~£70
  • Avg. price in US: ~$100
  • Form factor: wristband
  • Battery life: 5 days
  • Screen size: N/A inch

Fitbit Flex 2 review. Compare 171 technical specifications and user reviews to see how it ranks among fitness trackers and if it is worth buying.

6.6

Overall score

What it is: An overall evaluation of the fitness tracker's quality, based on technical analyses and user reviews.

When it matters: When you need a quick reference to identify the best fitness trackers on the market.

Score components:

80.0%

6.1

Technical Score

20.0%

8.6

User score

Good
6.1

Technical Score

What it is: An assessment of the fitness tracker's technical performance, covering eight key areas: health tracking, sports features, connectivity, display, battery, smart features, design, and app support.

When it matters: When you want to compare fitness trackers based on technical performance and available features.

Score components:

20.0%

8.3

Sports & Navigation

20.0%

3.5

Battery

18.0%

5.9

Health

18.0%

4.0

Display

8.0%

7.1

Smart Features

8.0%

9.0

App & Wellness

4.0%

8.7

Connectivity

4.0%

8.5

Design & Durability

Good
8.6

User score

What it is: A rating that combines user reviews and the total number of reviews received by the fitness tracker.

When it matters: When you want to know how a fitness tracker performs in daily use and how reliable it remains over time according to user feedback.

Score components:

70.0%

8.0

User reviews

30.0%

10

Popularity

User score:
United Kingdom
amazon
4.0
(4600)
amazon
3.9
(1232)
amazon
4.2
(1215)
amazon
3.5
(76)

(Reviews last updated: Jun 2026)

Excellent
  • 6.5
    Swimming

    Score components:

    28.0%

    10

    ATM rating

    24.0%

    4.0

    Open-water swim mode

    18.0%

    10

    Waterproof depth rating

    15.0%

    4.0

    GPS

    15.0%

    2.0

    Battery life

  • 5.6
    Kids

    Score components:

    30.0%

    2.0

    Battery life

    25.0%

    7.9

    Weight

    20.0%

    10

    ATM rating

    15.0%

    0.0

    Screen size

    10.0%

    10

    Price

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Best prices in UK

Best rankings

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Available: ranking among products currently available (including other versions of this product).
All: ranking among all products in the database.

Verdict

The Fitbit Flex 2 is an ultra-slim, minimalist fitness tracker featuring a removable 3-axis accelerometer module that is 30% smaller than its predecessor and water-resistant up to 50 meters. It automatically tracks daily steps, distance, calories burned, and sleep, and it is Fitbit's first device to offer automatic swim tracking for laps and duration. Main pros include its versatile design that can be worn in interchangeable bands, bangles, or pendants, and its discreet LED notification system for calls and texts. However, notable cons include the lack of a digital screen or clock, the absence of a heart rate monitor and altimeter, and a relatively short battery life of up to 5 days considering its limited display.

Technical Specifications of Fitbit Flex 2

Technical Score

What it is: An assessment of the fitness tracker's technical performance, covering eight key areas: health tracking, sports features, connectivity, display, battery, smart features, design, and app support.

When it matters: When you want to compare fitness trackers based on technical performance and available features.

Score components:

20.0%

8.3

Sports & Navigation

20.0%

3.5

Battery

18.0%

5.9

Health

18.0%

4.0

Display

8.0%

7.1

Smart Features

8.0%

9.0

App & Wellness

4.0%

8.7

Connectivity

4.0%

8.5

Design & Durability

6.1
Fitbit Flex 2 has a technical score of 6.12 points, which is lower than 86.4% of fitness trackers.
User score

What it is: A rating that combines user reviews and the total number of reviews received by the fitness tracker.

When it matters: When you want to know how a fitness tracker performs in daily use and how reliable it remains over time according to user feedback.

Score components:

70.0%

8.0

User reviews

30.0%

10

Popularity

User score:
United Kingdom
amazon
4.0
(4600)
amazon
3.9
(1232)
amazon
4.2
(1215)
amazon
3.5
(76)

(Reviews last updated: Jun 2026)

8.6
Fitbit Flex 2 has a user score of 8.62 points, which is higher than 70.4% of fitness trackers.
Popularity
What it is: An indicator based on the number of reviews received by the fitness tracker.
When it matters: When you prefer to buy a product chosen and reviewed by many other consumers.
10
Fitbit Flex 2 has a popularity of 10 points, which is higher than 60.1% of products in this category.
Ratio quality/price

What it is: An indicator that combines the fitness tracker's overall rating with its cost.

When it matters: When you are looking for a fitness tracker with a good balance between quality and price.

Score components:

60.0%

6.6

Overall score

40.0%

10

Price

7.6
Fitbit Flex 2 has a quality-to-price ratio of 7.6 points, which is lower than 66.2% of products in this category.
Heart rate monitor
What it is: Sensor that measures heart rate in real time.
When it matters: When you care about live heart-rate feedback during training or resting trends outside of workouts.

Importance: HIGH

no
Fitbit Flex 2 does not support heart rate monitoring. 60.3% of fitness trackers support heart rate monitoring.
Resting heart rate
What it is: Measures heart rate while resting.
When it matters: When deeper insight into sleep quality, recovery, or overall readiness matters more than raw numbers alone.

Importance: MEDIUM

no
Fitbit Flex 2 does not support Resting heart rate. 48.5% of fitness trackers support Resting heart rate.
Fast/slow heart rate alerts
What it is: Alerts for heart rates that are too fast or too slow.
When it matters: When you want the tracker to warn you about unusual changes instead of only logging them.

Importance: LOW

no
Fitbit Flex 2 does not support high and low heart rate alerts. 33.7% of fitness trackers support high and low heart rate alerts.
Irregular heart rate alerts
What it is: Warns of irregular or abnormal heart rhythms.
When it matters: When you want the tracker to warn you about unusual changes instead of only logging them.

Importance: LOW

no
Fitbit Flex 2 does not support irregular heart rate alerts. 11.5% of fitness trackers support irregular heart rate alerts.
Blood oxygen sensor
What it is: Sensor that measures blood oxygen saturation.
When it matters: When blood oxygen readings are part of the health picture you want from the device instead of relying on heart rate and step count alone.

Importance: MEDIUM

no
Fitbit Flex 2 does not have a blood oxygen sensor. 26.1% of fitness trackers have a blood oxygen sensor.
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GPS
What it is: Satellite navigation capability for positioning and tracking.
When it matters: When you train outdoors and want pace, distance, and route tracking without depending completely on your phone.

Importance: LOW

no
Fitbit Flex 2 does not have GPS. 11% of fitness trackers have GPS.
Satellite systems supported
What it is: States which satellite navigation systems the device can use for positioning.
When it matters: When you train outdoors and want stronger positioning, route guidance, and navigation independence from your phone.

Importance: LOW

no
Fitbit Flex 2 supports no satellite systems which is less versatile than that of 12.2% of fitness trackers and the same as that of 87.8% of fitness trackers.
GNSS bands supported
What it is: Number and type of GNSS frequency bands supported.
When it matters: When you train outdoors and want stronger positioning, route guidance, and navigation independence from your phone.

Importance: LOW

no
Fitbit Flex 2 does not support advanced GNSS bands. 8.9% of fitness trackers support advanced GNSS bands.
Galileo support
What it is: Supports Galileo satellite system.
When it matters: When you train outdoors and want stronger positioning, route guidance, and navigation independence from your phone.

Importance: LOW

no
Fitbit Flex 2 does not support Galileo. 4.9% of fitness trackers support Galileo.
Acquires GPS faster
What it is: Shows whether the tracker includes features that help it lock onto satellite positioning more quickly at the start of an outdoor activity.
When it matters: When you train outdoors and want stronger positioning, route guidance, and navigation independence from your phone.

Importance: LOW

no
Fitbit Flex 2 does not support faster GPS acquisition. 7.2% of fitness trackers support faster GPS acquisition.
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Notifications
What it is: Delivers smartphone notifications on the watch.
When it matters: When getting calls, messages, and app alerts on your wrist saves you from checking your phone constantly.

Importance: MEDIUM

yes
Fitbit Flex 2 supports notifications. 27.5% of fitness trackers support notifications.
vibration/LED alerts only.
Vibrating alerts
What it is: Provides vibration-based notifications and alerts.
When it matters: When staying reachable from your wrist helps you avoid checking your phone constantly.

Importance: LOW

yes
Fitbit Flex 2 supports vibration alerts. 16.3% of fitness trackers support vibration alerts.
Call control
What it is: Allows control of phone calls from the device.
When it matters: When staying reachable from your wrist helps you avoid checking your phone constantly.

Importance: LOW

no
Fitbit Flex 2 does not support call controls. 41.1% of fitness trackers support call controls.
Call answering
What it is: Allows answering calls directly from the device.
When it matters: When staying reachable from your wrist helps you avoid checking your phone constantly.

Importance: LOW

no
Fitbit Flex 2 does not support call answering. 1% of fitness trackers support call answering.
Calendar sync
What it is: Syncs calendar events with the connected device.
When it matters: When staying reachable from your wrist helps you avoid checking your phone constantly.

Importance: LOW

no
Fitbit Flex 2 does not support calendar sync. 19.9% of fitness trackers support calendar sync.
Show more
Activity reports
What it is: Generates summaries and insights from activity data.
When it matters: When you want the app to motivate you with goals, reports, coaching, or progress feedback over time.

Importance: LOW

yes
Fitbit Flex 2 supports activity reports. 5.7% of fitness trackers support activity reports.
via Fitbit app
Goal setting
What it is: Allows setting personal fitness or activity goals.
When it matters: When you want the app to motivate you with goals, reports, coaching, or progress feedback over time.

Importance: LOW

yes
Fitbit Flex 2 supports goal setting. 2.4% of fitness trackers support goal setting.
Achievements
What it is: Rewards progress and completed milestones.
When it matters: When you want the app to motivate you with goals, reports, coaching, or progress feedback over time.

Importance: LOW

yes
Fitbit Flex 2 supports achievements. 24.3% of fitness trackers support achievements.
Inactivity alerts
What it is: Alerts when the user has been inactive for too long.
When it matters: When account rules, app costs, exports, or software flexibility affect whether the ecosystem suits you long term.

Importance: LOW

yes
Fitbit Flex 2 supports inactivity alerts. 23.7% of fitness trackers support inactivity alerts.
Move reminders supported.
Coaching
What it is: Provides guided training and workout advice.
When it matters: When you want the app to motivate you with goals, reports, coaching, or progress feedback over time.

Importance: LOW

no
Fitbit Flex 2 does not support coaching. 33% of fitness trackers support coaching.
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Bluetooth version
What it is: Version of Bluetooth supported by the device.
When it matters: When wireless stability, pairing quality, and long-term phone compatibility matter more than Bluetooth being a simple checkbox.

Importance: LOW

Good value: >=5.0

4.0
Fitbit Flex 2 supports Bluetooth 4.0 which is newer than in 5.1% of fitness trackers and equal to that in 51.5% of fitness trackers.
Maximum Bluetooth range
What it is: States the maximum Bluetooth connection range supported under normal conditions.
When it matters: When compatibility with your phone, computer, accessories, or wireless setup affects how well the tracker fits into your ecosystem.

Importance: LOW

Good value: >=10 m

30 m
Fitbit Flex 2 offers a Bluetooth range of 30 m which is higher than that of 90.8% of fitness trackers and equal to that of 6.2% of fitness trackers.
NFC
What it is: Supports near-field communication for contactless features.
When it matters: When compatibility with your phone, computer, accessories, or wireless setup affects how well the tracker fits into your ecosystem.

Importance: LOW

no
Fitbit Flex 2 does not have NFC. 10.1% of fitness trackers have NFC.
Wi-Fi connectivity
What it is: Connects to wireless internet networks.
When it matters: When the tracker should sync, update, or download data directly without always routing everything through the phone.

Importance: LOW

no
Fitbit Flex 2 does not support Wi-Fi. 1.8% of fitness trackers support Wi-Fi.
no Wi-Fi connectivity.
Wi-Fi version
What it is: Version of Wi-Fi standard supported.
When it matters: When compatibility with your phone, computer, accessories, or wireless setup affects how well the tracker fits into your ecosystem.

Importance: LOW

no
Fitbit Flex 2 does not support modern Wi-Fi. 1% of fitness trackers support modern Wi-Fi.
no Wi-Fi support.
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Battery life
What it is: Total time the battery lasts on a full charge.
When it matters: When the tracker needs to last through travel, sleep tracking, long workouts, or several days between charges.

Importance: HIGH

Good value: >5 days

5 days
Fitbit Flex 2 offers a battery life of 5 days which is shorter than that of 79.2% of fitness trackers and equal to that of 12.4% of fitness trackers.
Battery life with GPS on
What it is: Battery duration when GPS tracking is active.
When it matters: When you want fewer charging breaks during travel, longer workouts, sleep tracking, or continuous use.

Importance: LOW

Good value: >=8 hours

N/A
Battery life in training mode
What it is: Battery duration during active training sessions.
When it matters: When you want fewer charging breaks during travel, longer workouts, sleep tracking, or continuous use.

Importance: LOW

N/A
Battery life in power-saving mode
What it is: Battery duration when using power-saving mode.
When it matters: When you want fewer charging breaks during travel, longer workouts, sleep tracking, or continuous use.

Importance: LOW

N/A
Battery capacity
What it is: Energy storage capacity of the battery.
When it matters: When you want rough battery context behind the runtime claim instead of trusting the advertised hours alone.

Importance: MEDIUM

Good value: >=100 mAh

25 mAh
Fitbit Flex 2 has a battery capacity of 25 mAh which is lower than that of 97.9% of fitness trackers.
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Display
What it is: Main interface showing information and metrics.
When it matters: When easier reading at a glance and better day-to-day screen comfort matter to you.

Importance: LOW

no
Fitbit Flex 2 does not have a display. 76.4% of fitness trackers have a display.
Uses indicator lights instead of a full display.
Screen size
What it is: Physical size of the device’s display measured diagonally.
When it matters: When easier reading at a glance and better day-to-day screen comfort matter to you.

Importance: MEDIUM

N/A
Display type
What it is: Technology used for the screen, such as AMOLED or LCD.
When it matters: When display technology affects contrast, color quality, power efficiency, or how premium the screen feels.

Importance: MEDIUM

N/A
Screen resolution
What it is: Total number of pixels displayed on the screen.
When it matters: When easier reading at a glance and better day-to-day screen comfort matter to you.

Importance: MEDIUM

N/A
Pixel density
What it is: Number of pixels per inch determining screen sharpness.
When it matters: When easier reading at a glance and better day-to-day screen comfort matter to you.

Importance: LOW

Good value: >=280 ppi

N/A
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Form factor
What it is: Overall physical design and shape.
When it matters: When materials, shape, and build details affect comfort, durability, or how discreet the device feels.

Importance: LOW

wristband
Hybrid design
What it is: Combines analog and digital display elements.
When it matters: When materials, shape, and build details affect comfort, durability, or how discreet the device feels.

Importance: LOW

no
Fitbit Flex 2 does not support Hybrid design. 2.4% of fitness trackers support Hybrid design.
Designed for kids
What it is: Indicates whether the fitness tracker is explicitly designed for children, with child-focused sizing, branding, safety limits, or kid-oriented activity features.
When it matters: This matters when you want a tracker that is genuinely child-focused rather than just a smaller adult model.

Importance: LOW

no
Fitbit Flex 2 is not designed for kids. 2.4% of fitness trackers are designed for kids.
No child-specific positioning found.
Replaceable watch band
What it is: Ability to replace the wristband with other styles.
When it matters: When strap comfort, fit, or the ability to swap bands matters for sport, style, or replacement.

Importance: LOW

yes
Fitbit Flex 2 has a replaceable watch band. 24.4% of fitness trackers have a replaceable watch band.
Band width
What it is: Width of the strap where it connects to the watch.
When it matters: When strap comfort, fit, or the ability to swap bands matters for sport, style, or replacement.

Importance: LOW

11 mm
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Fitbit Flex 2 vs the average fitness tracker

  • Tracks menstrual cycle
    Fitbit Flex 2 supports menstrual cycle tracking, while the average fitness tracker does not. 41.7% of fitness trackers support menstrual cycle tracking.
    Includes menstrual-cycle tracking.
    What it is: Tracks menstrual cycle and related data.
    When it matters: When cycle tracking is part of your health routine and you want those records kept alongside the rest of your wearable data.

    Importance: LOW

    Fitbit Flex 2 supports menstrual cycle tracking, while the average fitness tracker does not. 41.7% of fitness trackers support menstrual cycle tracking.
  • Windows compatible
    Fitbit Flex 2 is compatible with Windows, while the average fitness tracker is not. 22.3% of fitness trackers are compatible with Windows.
    Via Fitbit Windows app.
    What it is: Compatible with Windows computers.
    When it matters: When compatibility with your phone, computer, accessories, or wireless setup affects how well the tracker fits into your ecosystem.

    Importance: LOW

    Fitbit Flex 2 is compatible with Windows, while the average fitness tracker is not. 22.3% of fitness trackers are compatible with Windows.
  • Mac OS X compatible
    Fitbit Flex 2 is compatible with Mac OS X, while the average fitness tracker is not. 27.5% of fitness trackers are compatible with Mac OS X.
    Via Fitbit Connect.
    What it is: Compatible with macOS devices.
    When it matters: When compatibility with your phone, computer, accessories, or wireless setup affects how well the tracker fits into your ecosystem.

    Importance: LOW

    Fitbit Flex 2 is compatible with Mac OS X, while the average fitness tracker is not. 27.5% of fitness trackers are compatible with Mac OS X.
  • 4.2 mm thinner design
    Fitbit Flex 2 is thinner than the average fitness tracker (6.8 mm vs 11 mm). The average fitness tracker has a thickness of 11 mm.
    What it is: Total depth of the watch case.
    When it matters: When overall size, thickness, or weight affects comfort during all-day wear, sleep, or exercise.

    Importance: LOW

    Good value: <10 mm

    Fitbit Flex 2 is thinner than the average fitness tracker (6.8 mm vs 11 mm). The average fitness tracker has a thickness of 11 mm.6.8 mm vs 11 mm
  • 20 m longer Bluetooth range
    Fitbit Flex 2 has a longer Bluetooth range than the average fitness tracker (30 m vs 10 m). The average fitness tracker offers a Bluetooth range of 10 m.
    What it is: States the maximum Bluetooth connection range supported under normal conditions.
    When it matters: When compatibility with your phone, computer, accessories, or wireless setup affects how well the tracker fits into your ecosystem.

    Importance: LOW

    Good value: >=10 m

    Fitbit Flex 2 has a longer Bluetooth range than the average fitness tracker (30 m vs 10 m). The average fitness tracker offers a Bluetooth range of 10 m.30 m vs 10 m
  • Cycle start prediction
    Fitbit Flex 2 predicts the start date, while the average fitness tracker does not. 42.2% of fitness trackers predict the start date.
    Predicts the next period start date.
    What it is: Shows whether the platform can estimate when the next menstrual cycle is likely to begin.
    When it matters: When cycle tracking, fertility insight, or related reminders are part of your health routine.

    Importance: LOW

    Fitbit Flex 2 predicts the start date, while the average fitness tracker does not. 42.2% of fitness trackers predict the start date.
  • Ovulation prediction
    Fitbit Flex 2 predicts ovulation, while the average fitness tracker does not. 41.4% of fitness trackers predict ovulation.
    Predicts ovulation.
    What it is: Shows whether the health platform can estimate the ovulation window from tracked cycle data.
    When it matters: When cycle tracking, fertility insight, or related reminders are part of your health routine.

    Importance: LOW

    Fitbit Flex 2 predicts ovulation, while the average fitness tracker does not. 41.4% of fitness trackers predict ovulation.
  • Built-in route tracker
    Fitbit Flex 2 supports route tracking, while the average fitness tracker does not. 49.8% of fitness trackers support route tracking.
    Uses connected phone GPS for route maps.
    What it is: Shows whether the platform can record and save route history for outdoor activities such as running, hiking, or cycling.
    When it matters: When you want to review where you went after a workout instead of seeing only distance and time totals.

    Importance: LOW

    Fitbit Flex 2 supports route tracking, while the average fitness tracker does not. 49.8% of fitness trackers support route tracking.
  • Tracks menstrual cycle
    Fitbit Flex 2 supports menstrual cycle tracking, while the average fitness tracker does not. 41.7% of fitness trackers support menstrual cycle tracking.
  • Ovulation prediction
    Fitbit Flex 2 predicts ovulation, while the average fitness tracker does not. 41.4% of fitness trackers predict ovulation.
  • Cycle start prediction
    Fitbit Flex 2 predicts the start date, while the average fitness tracker does not. 42.2% of fitness trackers predict the start date.
  • Built-in route tracker
    Fitbit Flex 2 supports route tracking, while the average fitness tracker does not. 49.8% of fitness trackers support route tracking.
  • Auto lap
    Fitbit Flex 2 supports auto lap, while the average fitness tracker does not. 19.9% of fitness trackers support auto lap.
  • 7.1% higher maximum altitude
    Fitbit Flex 2 has a higher maximum altitude than the average fitness tracker (9,144 m vs 8,534 m). The average fitness tracker supports a maximum altitude of 8,534 m.
  • Windows compatible
    Fitbit Flex 2 is compatible with Windows, while the average fitness tracker is not. 22.3% of fitness trackers are compatible with Windows.
  • Mac OS X compatible
    Fitbit Flex 2 is compatible with Mac OS X, while the average fitness tracker is not. 27.5% of fitness trackers are compatible with Mac OS X.
  • 20 m longer Bluetooth range
    Fitbit Flex 2 has a longer Bluetooth range than the average fitness tracker (30 m vs 10 m). The average fitness tracker offers a Bluetooth range of 10 m.
  • 4.2 mm thinner design
    Fitbit Flex 2 is thinner than the average fitness tracker (6.8 mm vs 11 mm). The average fitness tracker has a thickness of 11 mm.
  • Tracks calorie intake
    Fitbit Flex 2 supports calorie intake tracking, while the average fitness tracker does not. 39.3% of fitness trackers support calorie intake tracking.
  • Water intake tracking
    Fitbit Flex 2 supports water intake tracking, while the average fitness tracker does not. 47% of fitness trackers support water intake tracking.
  • No heart rate monitoring
    Fitbit Flex 2 does not support heart rate monitoring, while the average fitness tracker does. 60% of fitness trackers support heart rate monitoring.
  • 5 days shorter battery life
    Fitbit Flex 2 has a lower battery life than the average fitness tracker (5 days vs 10 days). The average fitness tracker has 10 days of battery life.
  • 77.3% smaller battery capacity
    Fitbit Flex 2 has a lower battery capacity than the average fitness tracker (25 mAh vs 110 mAh). The average fitness tracker has 110 mAh of battery capacity.
  • No display
    Fitbit Flex 2 does not have a display, while the average fitness tracker does. 76.1% of fitness trackers have a display.
    Uses indicator lights instead of a full display.
  • No stopwatch
    Fitbit Flex 2 does not have a stopwatch, while the average fitness tracker does. 58.4% of fitness trackers have a stopwatch.
  • 10 °C higher minimum operating temperature
    Fitbit Flex 2 has a higher minimum operating temperature than the average fitness tracker (10 °C vs 0 °C). The average fitness tracker supports a minimum operating temperature of 0 °C.
  • Ads in app
    Fitbit Flex 2 shows ads in the app, while the average fitness tracker does not. 50.6% of fitness trackers have an ad-free app.
  • No heart rate monitoring
    Fitbit Flex 2 does not support heart rate monitoring, while the average fitness tracker does. 60% of fitness trackers support heart rate monitoring.
    What it is: Sensor that measures heart rate in real time.
    When it matters: When you care about live heart-rate feedback during training or resting trends outside of workouts.

    Importance: HIGH

    Fitbit Flex 2 does not support heart rate monitoring, while the average fitness tracker does. 60% of fitness trackers support heart rate monitoring.
  • 5 days shorter battery life
    Fitbit Flex 2 has a lower battery life than the average fitness tracker (5 days vs 10 days). The average fitness tracker has 10 days of battery life.
    What it is: Total time the battery lasts on a full charge.
    When it matters: When the tracker needs to last through travel, sleep tracking, long workouts, or several days between charges.

    Importance: HIGH

    Good value: >5 days

    Fitbit Flex 2 has a lower battery life than the average fitness tracker (5 days vs 10 days). The average fitness tracker has 10 days of battery life.5 days vs 10 days
  • 77.3% smaller battery capacity
    Fitbit Flex 2 has a lower battery capacity than the average fitness tracker (25 mAh vs 110 mAh). The average fitness tracker has 110 mAh of battery capacity.
    What it is: Energy storage capacity of the battery.
    When it matters: When you want rough battery context behind the runtime claim instead of trusting the advertised hours alone.

    Importance: MEDIUM

    Good value: >=100 mAh

    Fitbit Flex 2 has a lower battery capacity than the average fitness tracker (25 mAh vs 110 mAh). The average fitness tracker has 110 mAh of battery capacity.25 mAh vs 110 mAh
  • No stopwatch
    Fitbit Flex 2 does not have a stopwatch, while the average fitness tracker does. 58.4% of fitness trackers have a stopwatch.
    What it is: Built-in stopwatch for timing activities.
    When it matters: When buttons, crowns, gestures, or direct controls affect how quickly you can use the device mid-activity.

    Importance: LOW

    Fitbit Flex 2 does not have a stopwatch, while the average fitness tracker does. 58.4% of fitness trackers have a stopwatch.
  • Ads in app
    Fitbit Flex 2 shows ads in the app, while the average fitness tracker does not. 50.6% of fitness trackers have an ad-free app.
    What it is: Operates without advertisements.
    When it matters: When account rules, app costs, exports, or software flexibility affect whether the ecosystem suits you long term.

    Importance: LOW

    Fitbit Flex 2 shows ads in the app, while the average fitness tracker does not. 50.6% of fitness trackers have an ad-free app.
  • No display
    Fitbit Flex 2 does not have a display, while the average fitness tracker does. 76.1% of fitness trackers have a display.
    Uses indicator lights instead of a full display.
    What it is: Main interface showing information and metrics.
    When it matters: When easier reading at a glance and better day-to-day screen comfort matter to you.

    Importance: LOW

    Fitbit Flex 2 does not have a display, while the average fitness tracker does. 76.1% of fitness trackers have a display.
  • 4.4% worse value for money
    Fitbit Flex 2 has a lower value-for-money score than the average fitness tracker (7.63 vs 7.964).
    What it is: An indicator that combines the fitness tracker's overall rating with its cost.
    When it matters: When you are looking for a fitness tracker with a good balance between quality and price.
    Fitbit Flex 2 has a lower value-for-money score than the average fitness tracker (7.63 vs 7.964).7.63 vs 7.96
  • 10 °C higher minimum operating temperature
    Fitbit Flex 2 has a higher minimum operating temperature than the average fitness tracker (10 °C vs 0 °C). The average fitness tracker supports a minimum operating temperature of 0 °C.
    What it is: Lowest temperature the device can safely operate at.
    When it matters: When you use the tracker in tougher temperatures, humidity, altitude, or outdoor conditions.

    Importance: LOW

    Fitbit Flex 2 has a higher minimum operating temperature than the average fitness tracker (10 °C vs 0 °C). The average fitness tracker supports a minimum operating temperature of 0 °C.10 °C vs 0 °C

Graphic comparison of Fitbit Flex 2 and

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Third-party reviews

(Reviews last updated: Jun 2026)

What customers like about Fitbit Flex 2?

  • Slim, lightweight, and discreet design that is easy to forget you're wearing
  • Fully waterproof (swim-proof) with the ability to track swimming laps
  • Versatile customisation options, including interchangeable bands, bangles, and pendants
  • Automatic exercise detection (SmartTrack) for walking, running, and aerobic activities
  • Access to the user-friendly Fitbit app and its strong social/community features
  • Support for basic phone notifications (calls and texts) via vibrations and colour-coded LEDs

What customers dislike about Fitbit Flex 2?

  • No digital display or clock, making it reliant on a smartphone for most data
  • Battery life typically only lasts 4–5 days, which is lower than many non-screen competitors
  • LED notification patterns can be cryptic and difficult to decode without a 'decoder ring'
  • Lacks advanced sensors like a heart rate monitor, GPS, or altimeter for counting stairs
  • Proprietary charging cable is tiny, easy to lose, and requires removing the tracker from the band
  • The band's button clasp can be fiddly and difficult to secure for some users

Expert reviews

A
androidauthority.com
12/12/2016

Fitbit Flex 2 Review Summary The Fitbit Flex 2 is a lightweight, ultra-compact entry-level fitness tracker designed for casual users rather than serious athletes. Its standout features include a highly versatile, waterproof design that allows the core tracking unit to be swapped into various bands, bangles, or pendants. Performance-wise, it features exceptional automatic activity...Read more

A
androidpolice.com
30/11/2016

Fitbit Flex 2 Review Summary The Fitbit Flex 2 is praised as an incredibly small, lightweight, and "forgettable" activity tracker that features an upgraded, highly secure wristband clasp mechanism. As Fitbit's first device water-resistant up to 50 meters, it offers seamless, fully automatic tracking for sleep, daily steps, and workouts—including swimming—without requiring any manual...Read more

T
techradar.com
04/12/2019

The Fitbit Flex 2 is a lightweight and highly customizable fitness tracker designed for users seeking a simple, low-profile device without a digital display. Originally released as an upgrade to the 2013 original, it is roughly 30% smaller, comfortable enough to wear to sleep, and features full swim-ready water resistance—a milestone first for Fitbit. Its core hardware tracking...Read more

E
expertreviews.co.uk
27/02/2019

The Fitbit Flex 2 is an affordable, minimalist fitness tracker that excels at simple health monitoring, notable for being Fitbit's first fully waterproof device. It features an automatic "SmartTrack" mechanism that effortlessly logs exercises like cycling, gym sessions, and swimming lengths after 15 minutes of continuous activity. The tracker integrates seamlessly with its Android...Read more

F
forbes.com
12/12/2016

In his review for Forbes, Ben Sin identifies the Fitbit Flex 2 as a fashionable, ultra-slim tracker boasting a highly customizable design and, crucially, a fully waterproof build rated for 50-meter submersion, making it excellent for swimmers and style-conscious users. Its core pros include a discrete modular design, accurate step tracking, and automatic swim-style detection....Read more

S
stuff.tv
18/11/2016

The Fitbit Flex 2 is a budget-friendly, entry-level fitness tracker that focuses on simple and accurate tracking for everyday health goals. Priced around £75 ($100.88), the device stands out as Fitbit's first fully waterproof tracker, making it entirely safe for swimming or showering. It handles basic metrics like steps, sleep duration, and general exercise accurately. All of this...Read more

W
wareable.com
14/11/2016

The Wareable Fitbit Flex 2 review highlights the tracker as a highly customizable, ultra-discreet device, praised for being 30% smaller than its predecessor and featuring 50-meter water resistance, making it fully swim-proof. Key pros include SmartTrack automatic exercise recognition, comfortable design options for accessories, and essential, actionable vibrating move reminders....Read more

M
macworld.com
12/10/2016

The Fitbit Flex 2 is a lightweight, ultra-slim activity tracker priced at $100, designed to handle daily fitness basics silently in the background. A major standout feature is its water-resistant design, which allows users to take the band from the shower to the pool for automatic swim-tracking. The slim elastomer band is highly comfortable for continuous wear, and it relies on a...Read more

U
uk.pcmag.com
29/09/2016

The Fitbit Flex 2 is a lightweight, modular entry-level fitness tracker that stands out as Fitbit's first fully waterproof device, capable of tracking swimming stats like lap counts and pace down to 150 feet underwater. Its slim, ultra-lightweight design makes it highly comfortable for all-day wear. Instead of a digital display, the device utilizes a vertical row of five...Read more

T
trustedreviews.com
06/09/2016

The Fitbit Flex 2 is an ultra-slim, swim-proof tracker featuring a modular "pebble" design that can be worn in various accessories, allowing for automatic activity tracking and detailed insights via the Fitbit app. Its key strengths include a versatile, lightweight form factor, water resistance for swimming, and engaging motivational features. However, the tracker's major limitation...Read more

P
pocket-lint.com
05/09/2016

Fitbit Flex 2 Review Summary The Fitbit Flex 2 is a small, lightweight, and unobtrusive activity tracker designed for users seeking essential health data without the bulk of a traditional smartwatch. A major highlight of this model is its slim, customizable design featuring a removable tracking module that easily slips into a much more secure two-pin clasp band or other...Read more

E
endurancemag.com
06/02/2017

In this Endurance Magazine article, reviewer Rebecca Warriner evaluates the Fitbit Flex 2, highlighting it as an affordable, stylish, and functional entry-level device priced under $100. As a self-proclaimed non-gadget-eer, she praises several distinct pros of the tracker, such as its highly accurate step counting that intelligently filters out accidental movements by utilising...Read more

T
time.com
26/10/2016

The Fitbit Flex 2 is a streamlined, entry-level fitness tracker designed for budget-conscious buyers seeking an inconspicuous wearable. Retailing for $99.95, this model is 30% smaller than the original Flex and stands out for its high comfort, sleek aesthetics, and automatic exercise tracking, including a swim-proof build capable of handling submersion up to 50 meters. Reviewer Lisa...Read more

P
pcmag.com
29/09/2016

The Fitbit Flex 2 is a budget-friendly, modular tracker priced at $99.95 that features a fully waterproof, swim-ready design, allowing it to track swimming laps and duration. It features a modular, minimalist design with a swappable tracker unit, and relies on LED lights for notifications rather than a screen. The primary drawbacks include the lack of a display screen, no built-in...Read more

C
cnet.com
29/09/2016

The Fitbit Flex 2 is a sleek, budget-friendly fitness tracker priced at $100 (£80 / AU$130) that stands out as Fitbit's first entirely swim-proof device, capable of withstanding depths up to 50 meters in both fresh and salt water. Its incredibly slim, screenless design is 30% smaller than its predecessor and emphasizes high customisation; users can easily pop out the core tracking...Read more

C
chip.de
09/11/2016

The Fitbit Flex 2 review by CHIP highlights it as a highly minimalist and sleek entry-level fitness tracker that ultimately fails to fully impress. The device's standout feature is its fully waterproof, slim modular design, which allows the tiny core tracking module to be effortlessly swapped into an array of stylish, interchangeable accessories like colorful silicone bands,...Read more

C
computerbild.de
10/11/2016

The Computer Bild laboratory review awards the Fitbit Flex 2 an overall test score of 3.8 ("sufficient") after a test procedure adjustment changed it from an initial 2.5. The review highlights several notable pros, including its very comfortable, lightweight design, and a highly customizable form factor where the tracker module can be removed and swapped into various colored bands...Read more

F
fitness-tracker-test.info
06/07/2020

The Fitbit Flex 2 is a highly minimalist, ultra-slim tracker featuring a swim-proof design and a modular, lightweight build that allows it to be inserted into various accessories. It offers effortless background tracking, SmartTrack automatic exercise recognition, and provides goals via five LED indicator lights. However, the device lacks a digital display screen, forcing reliance...Read more

F
fitnessarmband.eu
26/05/2021

The Fitbit Flex 2 is a lightweight, 23.5-gram waterproof fitness tracker designed with a completely overhauled, display-less look featuring interchangeable bands and a 5-LED notification system. It excels in build quality, robust haptic feel, and highly accurate tracking capabilities, registering step counts with less than a 2% margin of error. The device provides automatic activity...Read more

F
fitnessuhr-tester.de
16/05/2020

The Fitbit Flex 2 is a highly minimalist, ultra-lightweight, and waterproof (up to 50 meters) modular tracker ideal for beginners, allowing users to swap the removable module between various wristbands and accessories. It boasts reliable SmartTrack technology for automatic activity and sleep tracking, along with a user-friendly app that provides clear visualizations of metrics....Read more

C
chip.de
04/11/2016

The CHIP laboratory review of the Fitbit Flex 2 paints a critical picture of Fitbit's entry-level fitness tracker, concluding that it fails to deliver a convincing user experience. A major upside highlighted in the review is its modular and highly customizable design, which features a ultra-slim, removable core unit that can be swapped into a variety of third-party or official...Read more

C
computerbild.de
07/12/2016

The COMPUTER BILD review of the Fitbit Flex 2 highlights its transition into a swim-friendly tracker. The device stands out for its waterproof design, making it suitable for both showering and swimming. It features a ultra-slim, lightweight build that can be converted into stylish bangles or pendants, alongside reliable automatic sleep tracking and precise step counting during daily...Read more

T
testbericht.guru
06/07/2020

Fitbit Flex 2 Review Summary The Fitbit Flex 2 is a compact, ultra-thin fitness tracker designed for users seeking a lightweight, discreet wearable that can be worn in straps, bangles, or pendants. A standout feature of this model is its fully waterproof design, making it swim-proof and capable of tracking pool laps, showers, or ocean swims. Despite lacking a digital screen, the...Read more

H
heise.de
21/11/2016

The Fitbit Flex 2 is reviewed as an ultra-minimalist, display-free tracker priced at €100, featuring a highly modular 23.5-gram core that can be worn in various bands or as a necklace. Key pros include 50-meter water resistance, reliable SmartTrack automatic activity and sleep recognition, and a five-day battery life. Conversely, the review highlights significant cons, including the...Read more

C
cnetfrance.fr
02/11/2016

The CNET France review for the Fitbit Flex 2 highlights the device as a highly capable, entry-level activity tracker that excels at basic data execution despite lacking the advanced bells and whistles of higher-end models. A major standout feature praised in the review is its redesigned, ultra-discreet form factor, which is 30% smaller and significantly thinner than the original...Read more

V
vonguru.fr
02/01/2017

The Fitbit Flex 2 is a compact fitness tracker praised for its lightweight, slim, and comfortable design, making it virtually unnoticeable to wear throughout the day and night. The absolute standout feature of this second generation is its complete waterproofing, which allows seamless activity tracking and accurate calorie counting during pool swimming. Users also benefit from...Read more

L
leclaireur.fnac.com
06/01/2017

The Fnac review evaluates the Fitbit Flex 2 as a sleek, ultra-discreet fitness tracker best suited for casual, city-dwelling users rather than hardcore athletes. The reviewer praises its comfortable, interchangeable elastomer wristband design, which comes in two sizes (14-17 cm and 16.5-20.6 cm) and secures safely with a stainless steel clasp. A major highlight is its new waterproof...Read more

L
lesnumeriques.com
03/12/2016

The Fitbit Flex 2 is a highly discreet, screenless fitness tracker that prioritises simplicity and a versatile, jewellery-like design. Weighing under 24 grams, the ultra-compact electronic module slots into included dual-size silicone bands featuring a highly secure double-prong stainless steel clasp. It relies on a system of five colour-coded LEDs and vibrations to communicate step...Read more

D
digitec.ch
06/07/2017

A six-month, long-term review by Digitec evaluates the Fitbit Flex 2, Charge 2, and Alta HR, highlighting the Flex 2’s waterproofing and the Charge 2's display as key strengths. While the Alta HR offers comprehensive, balanced health tracking, the test reveals significant data inaccuracies when worn on the ankle and a critical, restrictive requirement for mandatory smartphone GPS...Read more

E
elgrupoinformatico.com
12/01/2017

The review by El Grupo Informático highlights the Fitbit Flex 2 as a versatile, swim-proof tracker with five-day battery life, accurate step counting, and effective color-coded LED notifications for calls and texts. Its modular design allows it to be worn as a bracelet, bangle, or pendant, while its 30-meter water resistance makes it ideal for swimmers. While highly functional, the...Read more

C
correrunamaraton.com
21/03/2017

The Correr una Maratón review by Eduardo Mateos highlights the Fitbit Flex 2 as a highly minimalist and lightweight activity tracker, packaged inside a modular "bean" design that can be swapped into different bands. Its absolute standout pro is its complete waterproofing, making it the first and only device in the Fitbit lineup at the time capable of tracking pool swimming—such as...Read more

C
computerhoy.20minutos.es
20/12/2016

The Fitbit Flex 2 is a budget-friendly, screenless smartband praised for its highly customizable design and exceptional companion app. Retailing at an official price of €99, the device stands out with its removable tracking core that can be worn in interchangeable casual bands, premium designer bracelets, or even as a pendant. It provides remarkably accurate tracking for daily...Read more

A
andreagaleazzi.com
14/12/2016

The review by Andrea Galeazzi highlights the Fitbit Flex 2 as a remarkably slim, lightweight, and minimalist activity tracker that stands out for its simplicity. A major pro of this second-generation model is its 5 ATM waterproof rating, which introduces swimming tracking capable of measuring pool laps, active time, and calories burned. Users will appreciate the premium feel of the...Read more

T
tomshw.it
17/02/2017

The Fitbit Flex 2 is an affordable, lightweight, and slim fitness tracker priced under €100 that offers automatic activity tracking (SmartTrack) for running, cycling, swimming, and aerobic workouts. Weighing only 23 grams and featuring a 30% slimmer design than its predecessor, it includes a 3-axis accelerometer, a vibration motor, and a vertical 5-LED display that monitors daily...Read more

M
macitynet.it
24/12/2016

The Macitynet review highlights the Fitbit Flex 2 as an entry-level, highly customisable smartband designed for users seeking a lightweight and affordable tracker. Major advantages praised by the reviewer include its impressive waterproof design, allowing users to comfortably wear it in the shower or during pool swims, and its seamless, automatic tracking of daily steps, sports...Read more

S
smartworld.it
24/11/2016

The Fitbit Flex 2 is an ultra-lightweight, screenless fitness tracker designed to be worn discreetly inside a rubber wristband, metal bracelet, or pendant necklace. It features a core tracking capsule equipped with five front-facing LED lights—one multicoloured and four white—and a strong vibration motor to alert users of notifications and daily activity progress. The device...Read more

N
natuurlijklinda.nl
23/10/2016

The Fitbit Flex is a slim, lightweight activity tracker praised for its minimalist design that easily blends with any outfit. It provides accurate step tracking aligned with a default 10,000-step daily goal, which is displayed through five progress indicator lights. The device automatically monitors sleep patterns and estimates calorie burn based on user metrics. Its battery charges...Read more

Y
yourambassadrice.com
07/11/2016

Fitbit Flex 2 Review Summary The reviewer evaluated the lavender-coloured Fitbit Flex 2 fitness tracker, highlighting its sleek, feminine, and compact design that seamlessly blends with everyday jewelry. Key benefits include the automated sleep tracking feature—providing detailed insights into rest patterns and nighttime restlessness—and its capability to track diverse activities...Read more

C
coolesuggesties.nl
06/09/2014

The CooleSuggesties review of the Fitbit Flex highlights it as a sleek, modern silicone activity tracker designed to help users combat a sedentary lifestyle, particularly those with office jobs. Retailing at 99 euros, the tracker features a removable core module that slides into a wristband, utilizing a minimalist row of LED indicator lights to visually display daily progress toward...Read more

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