So you dug your Fitbit out of a drawer, got one as a gift, or picked one up second-hand — and now you’re staring at it wondering, “Which Fitbit do I actually have?”
You’re not alone. Fitbit has released dozens of trackers and smartwatches over the years, and a lot of them look almost identical. The Charge 3 and Charge 4? Nearly twins. The Versa 2 and Versa 3? Hard to tell apart at a glance. It happens to everyone.
The good news is that figuring out your exact Fitbit model takes less than two minutes when you know where to look. This guide walks you through every method — from checking the Fitbit app to reading the tiny model code on the back of the device — so you can identify your tracker with zero guesswork.
Let’s get into it.
Quick Answer: How to Identify Your Fitbit Model
The fastest way to identify your Fitbit model is:
- Open the Fitbit App on your smartphone
- Tap your profile icon
- Look at the connected device name listed under your profile
Your device will appear with its full name, such as Fitbit Charge 6 or Fitbit Sense 2.
If the tracker is not connected to the app, you can check the model number engraved on the back of the device.
Why Does It Matter Which Fitbit You Have?
Before we jump into the “how,” let’s talk about the “why” for a second. Knowing your exact Fitbit model matters more than you might think:
- Buying the right charger — Fitbit chargers are not universal. The Charge 6 uses a different cable than the Charge 5, and neither works with a Versa 2. Getting this wrong means a dead tracker.
- Buying compatible bands — Band sizes and attachment styles vary across models. A Luxe band won’t fit a Charge 4, even though they look similar.
- Troubleshooting correctly — Different models have different reset methods and firmware update paths.
- Selling or trading it — Buyers want to know the exact model.
- Understanding your features — Some models have built-in GPS. Others need your phone. Some have an ECG. Knowing your model tells you what you can actually do with it.
Bottom line: it’s worth taking two minutes to figure this out.
Method 1: Check the Fitbit App (Easiest & Most Reliable)
If your Fitbit is already paired to your smartphone, this is the fastest route.
- Open the Fitbit app on your phone (iOS or Android).
- Tap on your profile icon — it’s in the top-left corner on Android and top-right on iOS.
- Look just below your name. You’ll see your connected device listed by its full model name — for example, Fitbit Charge 6 or Fitbit Versa 4.
That’s it. The app pulls live data from your device, so what you see there is accurate.
Pro tip: If you need the model number rather than the name, go to Settings → About → Regulatory Info on the device itself. Scroll down, and you’ll find the model code (more on what those codes mean in a moment).
Method 2: Check the Back of the Device (Best for Unpaired Fitbits)
Every Fitbit has a model code printed or engraved on the back of the tracker, usually near the charging contacts or sensors. The code starts with FB followed by three digits — for example, FB417 or FB512.
Here’s how to read it:
- Flip your Fitbit over and look near the heart rate sensors or charging pins.
- You’re looking for a code like FB + three numbers.
- If the text looks faint, try cleaning the surface gently with a soft cloth and checking in good lighting.
Once you have the code, match it to the chart below.
Complete Fitbit Model Number Reference Chart
| Model Number | Fitbit Device |
| FB401 | Fitbit One |
| FB403 | Fitbit Flex |
| FB404 | Fitbit Charge |
| FB405 | Fitbit Charge HR (Charge 2) |
| FB406 | Fitbit Alta |
| FB407 | Fitbit Blaze |
| FB408 | Fitbit Alta HR |
| FB409 | Fitbit Charge 3 |
| FB410 | Fitbit Inspire |
| FB411 | Fitbit Ace 2 |
| FB412 | Fitbit Inspire HR |
| FB413 | Fitbit Versa Lite |
| FB414 | Fitbit Inspire 2 |
| FB415 | Fitbit Ace 3 |
| FB417 | Fitbit Charge 4 |
| FB418 | Fitbit Luxe |
| FB419 | Fitbit Charge 5 |
| FB420 | Fitbit Inspire 3 |
| FB421 | Fitbit Ace LTE |
| FB422 | Fitbit Charge 6 |
| FB502 | Fitbit Blaze |
| FB503 | Fitbit Versa |
| FB504 | Fitbit Ionic |
| FB505 | Fitbit Versa Lite |
| FB507 | Fitbit Versa 2 |
| FB509 | Fitbit Versa 3 |
| FB510 | Fitbit Sense |
| FB511 | Fitbit Versa 3 |
| FB512 | Fitbit Sense |
| FB513 | Fitbit Versa 4 |
| FB522 | Fitbit Sense 2 |
Note: Model numbers sometimes have additional letters after the digits indicating colour and size variants (e.g., FB417BKBK). The first five characters (FB + three digits) are what identify the model.
Method 3: Use Physical Design to Identify Your Fitbit
No app access? Can’t find the model code? Your eyes are still a solid identification tool. Fitbit’s product lines have distinct visual personalities once you know what to look for.
Fitbit Trackers (Band-Style Devices)
These are the slim, wristband-style devices — the ones that look more like a fitness tracker than a watch.
Fitbit Charge Series (Charge 3, 4, 5, 6)
The Charge lineup is Fitbit’s flagship tracker family. They have a slightly raised module sitting on top of a band, with a vertical touchscreen.
Charge 5 and 6 feature a colour display and a more polished stainless steel edge, while Charge 3 and 4 have a darker, more matte finish with a grayscale screen.
Fitbit Inspire Series (Inspire, Inspire HR, Inspire 2, Inspire 3).
The Inspire line is lighter and slimmer than Charge models. If your device feels almost weightless and has a small, simple display, it’s likely an Inspire. The Inspire 3 has a colour screen; earlier models do not.
Fitbit Luxe:
The Luxe is Fitbit’s fashion-forward tracker. It has a jewellery-like finish, a curved stainless steel body, and a full-colour display. If your tracker looks like something you’d wear to a dinner party, it’s a Luxe.
Fitbit Alta / Alta HR:
These are older, now-discontinued models with an ultra-slim metallic frame and a narrow horizontal screen. If your device is thin and elegant but has no colour and a very minimal display, it’s likely an Alta.
Fitbit Smartwatches
These look more like traditional watches — square face, interchangeable bands, larger display.
Fitbit Versa Series (Versa, Versa 2, 3, 4)
The Versa line has a signature square face with rounded corners. It’s Fitbit’s most popular smartwatch family.
One key way to tell Versa 3 from Versa 4 is the physical button — the Versa 4 has a raised button, while Versa 3 uses a flat capacitive groove.
Fitbit Sense / Sense 2
The Sense looks almost identical to the Versa. The main difference? It packs advanced health sensors, including ECG monitoring and EDA (electrodermal activity) for stress tracking.
The Sense 2 has a slightly slimmer profile and drops the rotating crown found on the original Sense.
Fitbit Ionic
The Ionic was Fitbit’s first serious GPS smartwatch. It has a more angular, slightly industrial look compared to the Versa. It’s been discontinued, but many are still in use.
Clip-On Trackers
Fitbit One / Fitbit Zip If what you’re holding is a small capsule or pebble-shaped device with a clip — not a wristband — you’ve got either a Fitbit One or a Fitbit Zip.
These were designed to clip onto clothing rather than be worn on the wrist. Both are discontinued but still used by plenty of people.
Method 4: Use the Device Settings Directly
If your Fitbit is powered on and functional, you can find the model info right on the device screen itself.
- Swipe left or navigate through the apps on your Fitbit to find Settings.
- Tap About.
- Look for Regulatory Info — scroll down, and the model number will be displayed at the top.
Keep in mind you’ll see the alphanumeric model code here (like FB417), not the plain English name. Use the chart above to match it to your device.
Method 5: Android Fast Pair (Great for Setup)
Here’s a trick that not many people know about. Since Google acquired Fitbit, many newer models support Android’s Fast Pair feature.
If your Fitbit is turned on but not yet set up, just bring it close to an Android phone running Android 8 or higher. The phone will automatically detect the device and display a notification that includes the model name.
This is especially handy when you can’t find the model number on the device and haven’t yet set it up.
How to Tell Apart Models That Look Almost Identical
Some Fitbit generations are genuinely hard to tell apart. Here are the most common mix-ups:
Charge 3 vs. Charge 4
They look virtually the same. The difference is in the features: Charge 4 added built-in GPS and Fitbit Pay (NFC). Look for the model code on the back — FB409 is Charge 3, FB417 is Charge 4.
Charge 5 vs. Charge 6
Both have colour screens and a premium stainless steel edge. Charge 6 gained Google integration features (Google Maps, Google Pay, and YouTube Music control). Check the app — it’ll tell you immediately.
Versa 2 vs. Versa 3
Versa 3 added built-in GPS and voice assistant support. Physically, the Versa 3 has a different side button — it’s a flat capacitive indent. The app will confirm the model name instantly.
Sense vs. Sense 2
The Sense 2 has a slimmer design, a side button instead of a rotating crown, and improved battery life. If your watch-style Fitbit has a small rotating crown on the side, you have the original Sense.
What If the Model Number Is Worn Off or Unreadable?
It happens — especially on older devices. Here’s what to try:
- Google Lens: Open Google Lens on your phone and point it at the device. It can sometimes identify gadgets visually and pull up the model details.
- Compare with official photos: Head to fitbit.com and browse the product pages. The current lineup is there, and for discontinued models, a quick image search usually turns up comparison photos.
- Check your charger: Each Fitbit series uses a specific charger type. Charge models use a clip charger. Versa and Sense models use a magnetic cradle. Inspire models use a clip with side contacts. Matching your charger to a known type can narrow things down significantly.
- Check your purchase history: If you bought it on Amazon, Walmart, or another retailer, your order history has the exact model name in the product title.
Quick Visual Summary: Which Fitbit Family Do You Have?
| What It Looks Like | Likely Fitbit Family |
| Slim band, tiny screen, very lightweight | Inspire Series |
| Slim band, thicker module, vertical screen | Charge Series |
| Slim band, polished metallic finish, jewellery-like | Luxe |
| Ultra-thin band, narrow horizontal display | Alta / Alta HR |
| Square watch face, rounded corners | Versa Series |
| Square watch face, advanced health sensors | Sense / Sense 2 |
| Angular watch, built-in GPS, older aluminium look | Ionic (discontinued) |
| Small capsule/pebble with clothing clip | One / Zip (discontinued) |
| Colourful, chunky design built for kids | Ace Series |
FAQ- Which Fitbit Do I Have?
Can I identify my Fitbit if it’s dead?
Yes. Remove the band and look at the back of the tracker itself — the model code is engraved there. You don’t need the device to be powered on.
What if the Fitbit app shows a different device than what I have?
This usually happens if you previously owned a different Fitbit and didn’t remove it from your account. Go into the app’s Devices section, tap the three dots next to the old device, select Remove, and then re-pair your current tracker.
Where exactly is the model number on older Fitbits?
On devices like the Alta, Charge 2, and Blaze, the model code is printed on the back panel near the sensor area. It can be quite small — use a flashlight and look closely.
Does Fitbit still support older models?
Support varies by model. Google (which owns Fitbit) has gradually wound down support for older devices. If you have a pre-2018 tracker, check Fitbit’s official support page for the current status.
Q: How do I know what Fitbit model I have?
The easiest way is through the Fitbit app:
Open the Fitbit app
Tap your profile picture (top-left)
Your connected Fitbit model name will be displayed
If your Fitbit isn’t paired or won’t turn on, check the back of the device for a model number (like FB407 or FB512) or go to Settings → About → Regulatory Info if it powers on.
Q: Can I identify my Fitbit by size or shape alone?
Partially. Some Fitbit models share similar designs.
For accurate identification, combine:
Screen shape
Button type (physical vs capacitive)
Sensors on the back
Model number
Example:
Versa 3 vs Versa 4 → button type
Sense 2 vs Versa 4 → advanced health sensors
Q: Where is the serial number on a Fitbit?
You can find your Fitbit serial number in several places:
Fitbit app → Profile → Device → Device Information
Back of the device (may require removing the band)
Original box or invoice
Fitbit website → Settings → Devices
Serial numbers usually start with FB or GA.
Q: How do I know if my Fitbit is charging?
Look for a battery icon or animation on the screen. No screen activity? Try a different charger or clean the contacts.
How do I determine what model of Fitbit I have (especially an older one)?
Older Fitbit models can look very similar, so use a combination of these methods:
Model number on the back of the tracker or band clasp
Design clues (screen shape, buttons, band style)
Charging cable type (many older Fitbits use unique chargers)
Once you find the model code, search:
“Fitbit FB407 model”
This works well even for discontinued Fitbits like Alta, Charge 2, Blaze, or Surge.
Final Thoughts
Identifying your Fitbit model really comes down to three quick steps: check the app if it’s paired, look at the back for the FB model code, and compare the physical design if the first two options aren’t available. You can have your answer in under two minutes.
Once you know your model, everything else gets easier — buying the right charger, finding compatible bands, accessing the correct troubleshooting guides, and understanding exactly which health features your device supports.
Got an older tracker you’re not sure about? The model code on the back, combined with the reference chart above, should give you a definitive answer every time.
Also Look: –
- Fitbit’s Top Budget Smartwatch Drops to Just $80!
- Your Fitbit Is Lost? Don’t Panic! Here’s How to Find It in Minutes.
- How to Setup YouTube Music Control on Fitbit Charge 6.
- Fitbit Not Tracking Steps? How to Fix.
- How to Use Spotify on Fitbit Versa 2: Easy Steps & Tricks.
- 11 Signs Your Fitbit is Dying: Is it Time to buy a new Fitbit?
2 Comments
what model is this Fitbit?
model fitbit “3F15F09850E1”
I think The serial number “3F15F09850E1” corresponds to a Fitbit Charge 4