








⌚ Elevate your wellness game with Fitbit Sense 2 — where smart meets stylish.
The Fitbit Sense 2 is a cutting-edge health and fitness smartwatch featuring continuous heart rate monitoring, ECG app for atrial fibrillation detection, SpO2 tracking, built-in GPS, and advanced stress and sleep management tools. Designed for all-day wear with a sleek aluminum case and customizable bands, it offers 6+ days of battery life, Bluetooth connectivity for calls and notifications, and includes a 6-month Fitbit Premium trial for personalized insights. Water resistant up to 50 meters, it supports over 40 exercise modes and automatic workout tracking, making it a comprehensive wellness companion for the modern professional.







| ASIN | B0B4MV1TGL |
| Additional Features | Sleep Monitor, Stress Monitor, Sleep Monitor, ECG, Oxymeter (SpO2), Heart Rate Monitor, GPS, Time Display, Notifications, Water Resistant |
| Age Range Description | Adult |
| Band Color | Blue |
| Band Material Type | Silicone |
| Battery Average Life | 6 days |
| Battery Capacity | 162 Amp Hours |
| Battery Cell Type | Lithium Ion |
| Battery Charge Time | 12 minutes |
| Best Sellers Rank | #770 in Electronics ( See Top 100 in Electronics ) #22 in Smartwatches |
| Brand | Fitbit |
| Built-In Media | Watch, Band |
| Case Material Type | Aluminum |
| Color | Blue Mist/Pale Gold |
| Communication Feature | [PARTIAL] Bluetooth for call and message alerts |
| Compatible Devices | Smartphone |
| Compatible Phone Models | Wide range of smartphones |
| Connectivity Technology | Bluetooth |
| Controller Type | Android |
| Customer Reviews | 4.2 out of 5 stars 9,380 Reviews |
| Display Type | AMOLED or OLED |
| GPS Geotagging Functionality | Built-in GPS |
| Human Interface Input | Touchscreen |
| Item Dimensions | 1.57 x 0.47 x 1.57 inches |
| Item Height | 4 centimeters |
| Item Weight | 1.3 Ounces |
| Manufacturer | Fitbit Inc |
| Memory Storage Capacity | 4 GB |
| Metrics Measured | [Multiple] |
| Model Name | Fitbit Sense 2 |
| Model Number | FB521GLBM-US |
| Operating System | Android |
| Resolution | 348 x 348 |
| Screen Size | 1.58 Inches |
| Shape | Square |
| Sim Card Size | eSIM |
| Special Feature | Sleep Monitor, Stress Monitor, Sleep Monitor, ECG, Oxymeter (SpO2), Heart Rate Monitor, GPS, Time Display, Notifications, Water Resistant Special Feature Sleep Monitor, Stress Monitor, Sleep Monitor, ECG, Oxymeter (SpO2), Heart Rate Monitor, GPS, Time Display, Notifications, Water Resistant See more |
| Sport Type | Fitness |
| Style Name | Modern |
| Supported Application | GPS, Phone, Voice Assistant |
| Supported Satellite Navigation System | GPS |
| Target Audience | Unisex Adult |
| UPC | 810073611436 |
| Unit Count | 1.0 Count |
| Warranty Description | 1 year manufacturer |
| Warranty Type | Limited |
| Water Resistance Depth | 164 Feet |
| Water Resistance Level | Water Resistant |
| Waterproof Rating | [IPX4 or better] |
| Wearable Computer Type | Smart Watch |
| Wireless Communication Standard | Bluetooth |
| Wireless Compability | Bluetooth |
| Wireless Provider | Unlocked |
J**.
Easy to customize the app and watch to my needs
I purchased this watch primarily for its continuous heart monitoring, ECG app, sleep monitoring, plus some basic fitness like steps and stairs. It was easy to install. I was pleased to be able to turn off the GPS and Alexa which may have been good for an extra day of battery life. I was able to turn off the fitness nags. I've been running and working out over 40 years and don't need nags. I was also able to skip the Premium service since I don't want a monthly bill and don't want other nagging. There are a huge number of watch faces available. I focused only on free watch faces. One thing that wasn't clear is that apparently you can only install 6 faces on the watch. When I found a better choice, it wouldn't install and had no useful explanation of why not. I ended up looking specifically for watch faces that included a battery indicator (surprisingly not universal!) and basic fitness figures. The hard part was finding watch faces that increased the font size of the battery % and fitness figures so they were more easily legible to older eyes. The biggest problem is with the watch band. I have a narrow wrist and bands with holes like the OEM band are never spaced in a way that fits well. So I ordered a new band that is metal mesh and uses a clamp to fix the length. That works to get a comfortable fit, but is a pain to put on. Good thing I only take the watch off once a day! So I tried another watch band that had a folding clasp, like my old watch band, and is adjusted in length by removing links. The whole process of removing links was a serious pain, requiring a magnifying ring light and great patience. And the link removal did not yield a snug and comfortable fit, just as with the OEM watch band. Back to the band that works, for now. Update. I just discovered it is possible, apparently, to get an adapter from my old watch band that attaches to the watch with pins to the FitBit clamp system. I'm hoping that will allow me to use my old watch band which was excellent. Further update: https://www.amazon.com/dp/B0BN1RVM5W?psc=1&ref=ppx_yo2ov_dt_b_product_details This adapter took a long time to arrive all the way from China, but it worked perfectly. My old watch band was a 20mm band with adjustable sizing clamp and a folding clasp to take it on and off: https://www.amazon.com/gp/product/B08CY5D2LB/ref=pe_2313400_740551120_em_1p_0_lm?th=1 Now I have the best of all worlds. A good watch and it is easy to put on and take off with a snug fit. I wonder why no one seems to make this style of watch band specifically to fit the FitBit?
A**E
Beautiful Tracker, Great Features, No Problems Using in the Pool
Update to my previous review: Leaving at 5 stars for quality, durability, and features. Battery life seems to be about the same as my old Fitbit HR. Initially, I got about 5 days out of the first couple of charges. Now I'm getting about 3-4. I have no problem with that. I charge my phone more often so I don't know why I would expect more from my fitness device. How quickly the battery drains seems to be dependent on my level of activity. I just check every day to see how much it's drained so I don't get caught out with a dead battery. Haven't allowed it to go less than 20%. It does not track steps accurately when I do pool exercises. I manually calculated about 2400 steps during my pool therapy and the tracker only counted a bit over 1900, including steps walking to and from the pool and so forth. All total, there should have been closer to 3000 steps so that's a pretty big disparity. Frankly, I have not found any fitness tracker to be very accurate with step count during exercise as it depends on how much arm swing is involved. Previous Review: Received my Fitbit Sense 2 (Mist blue and light gold) a few days ago and I love almost everything about this fitness tracker. The mist blue color is a pale blue-grey. The watch casing is a soft gold color like you might see on a car. It matches the seller's photo perfectly (on my PC monitor anyway.) I think it's very pretty, albeit larger than I like in a watch. I have tiny wrists and large watch bands/faces are awkward on me. But, to get the features I wanted, it's worth getting used to. I don't care for silicone bands as they don't breathe but I suppose for a sport watch, it might be the best option. The buckling system was concerning for me because you have to pop the band hole over a pin, then tuck it under on the other side against your wrist. It looked like it would be uncomfortable to clasp it and wear, but I'm happy to say it's not. Just feels a bit weird to me because it's bulky for my wrist size. It was relatively easy to set up. The only difficulty I had was when I logged into my Fitbit app previously associated with my Fitbit Charge HR, it kept asking me to log into my account, but I was already logged in. When I entered my password, it said it was incorrect but it wasn't. I finally tried using my email PW and got into my account. What was confusing was, the Fitbit logo was at the top next to, "log into your account." So, buyer be aware, if you have to log into an existing Fitbit account, they want your email address/PW, not Fitbit PW. The biggest reason I chose this model was for water use. I have to do pool therapy and wanted all my steps and activities to be logged in real-time. I wore it in the pool, hot tub, and shower today and there were no problems with it at all. Just be sure to read all the instructions carefully. You can get more info on the Fitbit website for details on setup, use, and care. The device only came with quick setup instructions in the box. I haven't really paid much attention to the sleep tracking as I have a sleep number bed that tracks that. And I haven't compared it against another heart rate monitor. However, based on the level of activity and how I felt during pool walking and exercises, it seemed like the numbers were relatively accurate. My favorite feature is the hourly buzz to get moving. It not only buzzes on my wrist to alert me it's time to move, but after I get up and walk around, it buzzes again to let me know I've completed 250 steps (based on my current setup.) This feature is priceless as I sit at a PC all day and forget to move. Overall, 3 days in, I'm very happy with this purchase and feel that the price was fair compared to similar devices with the same features. It also came with 6 months of free premium app services which I appreciate because it gives me a good amount of time to decide if I want to continue with the premium for a monthly fee. I do not find that app either intuitive or user-friendly and it will take some time for me to get the hang of using it. Should I run into any problems with my Sense 2 in the future I'll update this review.
J**R
Great fitness tracker
I have worn my Sense 2 for a week now. Just absolutely love it. I do wish I had dug a bit deeper to find out that Apple does not sync for text messaging (apparently only Android does) but you do get call alerts. I’m a nerd when it comes to my own bodies statistics so getting to learn about my sleep, my skin temp, and track my walking and workouts has been so much fun.
V**N
Does the job, usually
Overall it seems to be a great watch. I specifically bought this for my mother because she had a stroke and I wanted her to be able to check for a-fib. I also wanted her to be able to monitor her heart rate and oxygen levels. Ecg- its finicky, you have to really play with the placement of your fingers in order to get it to start reading, then most of the time the results are inconclusive. This part of the watch is supposedly designed by cardiologists and approved for 98.8% accuracy. The process to actually see the ecg graph is unnecessarily difficult. Samsung does a much better job in this category. The setup is easy, and straightforward. The app is also pretty straightforward and easy to use. Overall its a pretty standard smartwatch, with a few extra health monitoring related features. If you're looking for a watch to track a-fib, id probably steer away from this one. Otherwise it seems great.
C**Y
Utterly worthless!
After 5 years of good service my old Versa was struggling to keep a charge for 24 hours so I decided to replace it with a Sense 2. Huge mistake! This device drops to 20% charge in about 12 hours and then requires charging for about 2 hours. You can wear it during the day or at night, but you really can’t do both unless you set aside a couple of hours for charging. The watch has all sorts of sensors, but they all need to be turned off if you want 12 hours of life. Searching the message boards this seems common. I will play with the recommendations Insee there for a couple more days before returning it, but I’m not hopefull. It is inexcusible for a company to try to market a product that falls so short of their written claims! Avoid Fitbit if you are looking for a smart watch! Update: Turning off things like stress management and a restart apear to have imroved the battery life. Yesterday it dropped to about 60% including a 40minute walk with the GPS on. Unfortunately, it won’t charge back to 100% in the time it takes me to shower and dress like my old Versa. So it is probably a charge twise a day affair rather than the advertized once every 6 days. As others have remarked, the HR monitor seems to be incredibly inaccurate. It takes quite a while to react when starting a vigourous exercise and the HR laghs the obvioud signs like heavy breathing by several minutes. It barely registers exercises like the rowing machine in spite of the evident level of exertion. On a very steep hill that left me huffing and puffing it barely cracked into the fat burn zone. For some reason, the weather app has decided to stop working, too. The Google Maps shows turns that have nothing to do with the route being shown on the phone. This came and went, but I certainly wouldn’t trust it if I needed to get somewhere. I’m still quite dissatisfied. More later… Well, I did get the weather app to work by turning location services to “always”. On days I don’t use GPS I can actually charge it during my morning shower and get close to 100%. The heart beat monitor continues to be awful. My old Versa was often slow to recognize exercise, but the Sense 2 can take 10 minutes to even notice increased heart rate. I started the trial offer on Premium but don’t see anything there that would persuade me to pay for it once the trial period ends. Further update - for some reason, the Sense 2 has begun to mistake driving for bicycling. Based on it’s claims, I should easily win the tour de france. Pretty good for an old fat guy😃 Update after another month. The charging seems to have sorted itself out enough that I only need to charge once per day. The GPS IS some sort of random number generator, with the distance for the same exact walk varying by around 30% from day to day. Very brisk walks often show a slower pace than casual strolls. The Sense has begun to begrudgingly acknowledge my heart is beating during rowing sessions, but is wildly inaccurate. For the stationary bike it tends to not register anything, then overshoot to ridiculous levels before settling in to reasonable agreement with the HR monitor on the bike. The sleep logging seemed to stop at 14 days even though I have worn the Sense every night for at least 40 days. I’m not sure I care what my “sleep animal” is anyway - is this intended for children, or what??? My next fitness tracker/smart watch will definitely not be Fitbit. I will miss having 7 or so years of history, but if most of it is bogus, who cares?
C**K
Healthy upgrade
After having a dud with my first order, this watch is perfect for my needs. Connects quickly with long battery life. The ECG readings match the ones I get off of my Kardia unit. Very accurate on the heartbeat and oxygen levels.
****
Very affordable for how much it offers
This Fitbit smartwatch is a great deal for how much it offers. Our purpose for purchasing these are to keep track of our Heart Health...a great plus is that we are able to share records with our doctor. The size is great, I am able to keep track of time without needing glasses. We love that we are able to keep track of our sleep patterns, do an ECG and so much more ...it focuses on how each individual body functions (great thing about smart watches) rather then using general information. The one downside about this....it requires a subscription. Now it comes with a free 6month premium subscription.... it's loaded with helpful action suggestions to keep your mind body and spirit strong. I believe the cost after the 6 month free trial is $79 a year ...but well worth it for all the potential health benefits. We like things simple ...and even though it we are still figuring things out ...this smartwatch is pretty simple to maneuver through.
M**Y
Eh it’s alright
While this watch has some strong points, it does have its drawbacks. After nearly six months of use, you’re either a fan or you’re not. In my view, the Fitbit Sense 2 doesn’t match the responsiveness or intuitiveness of the Apple Watch. For instance, even though wrist flipping to wake the screen is enabled, it often fails to respond as expected. I’ve also experienced several heart arrhythmias and pauses while wearing the Fitbit (confirmed by a Cardiology halter monitor), but the Fitbit didn’t pick up on any of them, making the feature useless to me. Another issue is the workout tracking. If I forget to manually end a session, the watch at times won’t recognize the inactivity, continuing for hours after the workout is finished, which negatively affects the accuracy of data for that day. I have to manually make the corrections at times. Sleep tracking also falls short. It often misinterprets how long I’ve been awake, logging a 6.5-hour sleep as 8 hours if I remain in bed (e.g., logging times when I’m awake as “light sleep”), which skews the wellness and readiness metrics. I didn’t have these issues with my Apple Watch. Additionally, dealing with third-party vendors for custom watch faces, through the app, isn’t as seamless as contacting Apple customer service for support with an Apple Watch. While wearing the watch continuously to track sleep and daily activities seems ideal, I’ve had concerns about skin irritation, peeling, and even an odd odor developing after extended wear. I’ve since switched the wristband to something more skin-friendly. However, given that it’s a Bluetooth device, I do wonder about the safety of wearing it 24/7. Another disappointment is the wellness feature and notifications, which feel frequent and unnecessary, despite being a primary reason for my purchase. It’s as if the watch is constantly asking trivial questions like whether the sky is blue & isn’t very helpful. I’ve since switched it off. On the positive side: • The battery life is quite impressive, lasting days, and charging quickly. • I appreciate the step counting, goal setting, and the subtle vibration for alarms. The way the data is laid out is user-friendly, very detailed and great for tracking trends. • Customizing the watch face, including colors, and the features you wish to see are great. • The sleek design is also light weight and appealing. All in all, it has positives but lacks in some of the more important areas. If returning it was still an option, I’d likely consider exploring other options, possibly even return to an Apple Watch.
Trustpilot
2 weeks ago
2 weeks ago