The fastest answer: Open the Fitbit app → tap your profile picture (top-left on Android, top-right on iOS) → your Fitbit model name appears right there. Done.
No app access? Flip your Fitbit over. Look for a code starting with FB followed by three numbers — like FB422 or FB513. Match that code to the chart below and you have your answer in seconds.
Still stuck? Keep reading — this guide covers every method, including how to tell apart models that look nearly identical.
First: Make Sure You Have the Right Fitbit App
Before anything else — if you do not have the Fitbit app on your phone, or you lost it and cannot find it again, here is exactly what to download.
The official app is simply called “Fitbit” — made by Google LLC.
There are dozens of third-party apps in both app stores that use the Fitbit name, logos, and branding. Most of them are useless for identifying your device or syncing data. Only the official Google app works.
On iPhone (iOS)
- Open the App Store
- Search for Fitbit
- Look for the app with the aqua/teal diamond icon — developer listed as Google LLC
- If you already downloaded it before, scroll down on that same page and tap Redownload — it is free and your account data is still there
On Android
- Open the Google Play Store
- Search for Fitbit
- The official app shows Google LLC as the developer
- Tap Install — it is free
Already have the app but lost your account? Tap “Sign In” on the welcome screen and use the same email address you used when you first set up your Fitbit. Your data and device history are saved to your account — not your phone.
Quick tip: Once the app is installed and you sign in, your Fitbit model name appears automatically on the home screen. This is the fastest way to identify which model you have — no guessing required.
Why Knowing Your Fitbit Model Actually Matters
Before jumping into the how, here is why this is worth two minutes of your time:
- Chargers are not universal. The Charge 6 uses a completely different cable than the Charge 5. Buying the wrong one means a dead tracker.
- Bands are not interchangeable. A Luxe band will not fit a Charge 4, even though they look similar on the wrist.
- Reset methods differ by model. A Versa 4 reset is nothing like a Charge 6 reset. Following the wrong guide wastes time and can cause issues.
- Selling or trading it. Buyers always ask for the exact model name — and they should.
- Understanding what your tracker can actually do. Some models have built-in GPS. Others need your phone. Some have ECG. Knowing your model tells you what features you actually have access to.
Method 1: Check the Fitbit App (Fastest, Works 90% of the Time)
If your Fitbit is paired to your phone, this takes about ten seconds.
- Open the Fitbit app on your iPhone or Android phone
- Tap your profile picture — top-left corner on Android, top-right on iOS
- Your connected device appears by its full name directly below your name
You will see something like Fitbit Charge 6 or Fitbit Versa 4 — no guessing required.
If you need the model code too (for warranty claims or resale): on the device itself, go to Settings → About → Regulatory Info. Scroll down and you will find the alphanumeric model code.
Method 2: Read the Code on the Back of the Device
Every Fitbit ever made has a model code printed or engraved on the back, near the charging contacts or heart rate sensors.
The code always starts with FB followed by three digits. For example: FB417, FB513, FB522.
How to find it:
- Remove the band if it is covering the back panel
- Look near the sensor cluster or charging pins
- If the text looks faint, use a flashlight and look at an angle
Once you have the code, find it in the chart below.
Complete Fitbit Model Number Reference Chart (All Models)
| Model Code | 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: Codes sometimes have extra letters for color and size variants — for example FB422BKBK. Only the first five characters (FB + three digits) identify the model. Ignore everything after.
Method 3: Identify by Physical Design
No app, no code visible? Your eyes can still get you there. Each Fitbit family has a distinct look once you know what to look for.
Band-style trackers
Charge series (Charge 3, 4, 5, 6) A slightly raised rectangular module sitting on top of the band, with a vertical touchscreen. Charge 5 and 6 have a color display and polished stainless steel edge. Charge 3 and 4 have a darker matte finish with a grayscale screen.
Inspire series (Inspire, Inspire HR, Inspire 2, Inspire 3) Lighter and slimmer than Charge models. If your device feels almost weightless and has a small simple display, it is likely an Inspire. Inspire 3 has a color screen — earlier models do not.
Luxe Fitbit’s fashion-forward tracker. Curved stainless steel body, jewelry-like finish, full-color display. If your tracker looks like something you would wear to dinner, it is a Luxe.
Alta and Alta HR Discontinued but still common. Ultra-slim metallic frame, narrow horizontal screen, no color. If your tracker is thin and elegant but minimal, it is likely an Alta.
Smartwatch-style devices
Versa series (Versa, Versa 2, Versa 3, Versa 4) Square face with rounded corners — Fitbit’s most recognizable smartwatch family.
The Versa 4 has a raised physical button on the side. The Versa 3 has a flat capacitive indent in the same spot (no actual button).
Sense and Sense 2 Looks almost identical to the Versa. The original Sense has a small rotating crown on the side. The Sense 2 replaced it with a flat button and has a slightly slimmer profile.
Ionic Fitbit’s first serious GPS smartwatch. More angular, slightly industrial compared to the Versa. Discontinued but still in use.
Clip-on devices
Fitbit One and Fitbit Zip Small capsule or pebble-shaped device with a clothing clip — not a wristband. If what you are holding clips to your shirt rather than your wrist, it is one of these. Both discontinued.
Method 4: Check Device Settings Directly
If your Fitbit is powered on:
- Swipe left or navigate to Settings on the device
- Tap About
- Find Regulatory Info and scroll down
You will see the model code (like FB417). Match it to the chart above for the full name.
Method 5: Android Fast Pair
Newer Fitbit models support Android Fast Pair. If your Fitbit is turned on but not set up yet, bring it close to an Android phone running Android 8 or higher. The phone will show a notification with the device’s model name automatically — no setup required.
How to Tell Apart Models That Look Almost Identical
These are the most common mix-ups:
Charge 3 vs Charge 4 They look virtually the same. The key difference is inside — Charge 4 has built-in GPS and Fitbit Pay (NFC). Check the back: FB409 is Charge 3, FB417 is Charge 4.
Charge 5 vs Charge 6 Both have color screens and a premium edge. Charge 6 added Google integration — Google Maps, Google Pay, and YouTube Music control. The app will tell you instantly.
Versa 2 vs Versa 3 Versa 3 has built-in GPS and voice assistant support. The physical giveaway: Versa 3 has a flat capacitive groove on the side instead of a physical button.
Sense vs Sense 2 The original Sense has a small rotating crown on the side. The Sense 2 has a flat button and a slimmer profile.
What If the Model Number Is Worn Off?
Try these:
- Google Lens — Point your phone camera at the device. It can often identify gadgets visually.
- Your charger — Charge models use a clip charger. Versa and Sense models use a magnetic cradle. Inspire models use a clip with side contacts. Matching charger type narrows things down significantly.
- Purchase history — If you bought it on Amazon or another retailer, your order history has the exact model name in the product title.
- Official photos — Head to fitbit.com and compare with product images. For discontinued models, a quick image search usually turns up side-by-side comparison photos.
Quick Reference: Which Fitbit Family Do You Have?
| What it looks like | Likely family |
|---|---|
| Slim band, tiny screen, very lightweight | Inspire series |
| Slim band, thicker module, vertical screen | Charge series |
| Slim band, polished metallic finish | Luxe |
| Ultra-thin band, narrow horizontal display | Alta or Alta HR |
| Square watch face, rounded corners | Versa series |
| Square watch, advanced health sensors, ECG | Sense or Sense 2 |
| Angular watch, older aluminum look | Ionic (discontinued) |
| Small clip-on capsule | One or Zip (discontinued) |
| Chunky colorful design for kids | Ace series |
Now That You Know Your Model — What’s Next?
Once you have identified your Fitbit, here is what most people do next:
Need a replacement charger?
Every Fitbit series uses a different charger. Getting the wrong one is the most common mistake.
Search Amazon for your exact model — for example “Fitbit Charge 6 charger” — and check the listing carefully. Fitbit Charge 6 replacement chargers on Amazon.
Thinking about upgrading?
If you have an older model like a Charge 3, Charge 4, or Versa 2, Google has officially ended software support. That means no new features and limited troubleshooting. Here is how current models compare:
| You have | Upgrade worth considering | Why |
|---|---|---|
| Charge 3 or 4 | Fitbit Charge 6 | Color screen, Google Pay, built-in GPS |
| Versa 2 | Fitbit Versa 4 | Built-in GPS, Google integration, longer battery |
| Inspire 2 | Fitbit Inspire 3 | Color display, better heart rate sensor |
| Sense | Fitbit Sense 2 | Slimmer, better battery, simplified design |
Need replacement bands?
Band compatibility depends on your specific model — they are not all interchangeable. Search your model name plus “replacement band” on Amazon to see compatible options.
Your Fitbit still supported?
Google (which owns Fitbit) has wound down support for pre-2019 trackers. If you have an Alta, Charge 2, Blaze, or Ionic, some features may no longer work correctly. It may be time to consider a replacement.
How to Tell If You Have a Fitbit Inspire (vs Other Slim Models)
This is one of the most common mix-ups — the Inspire, Alta, Luxe, and Charge families all look like slim bands at first glance. Here is how to tell them apart quickly.
If your band feels almost weightless and has a tiny vertical screen — it is almost certainly an Inspire.
| Feature | Inspire / Inspire 2 / Inspire 3 | Charge 5 / Charge 6 | Luxe | Alta / Alta HR |
|---|---|---|---|---|
| Screen orientation | Vertical, narrow | Vertical, slightly wider | Vertical, slim | Horizontal, very narrow |
| Color screen | Inspire 3 only | Yes | Yes | No |
| Physical button | No | No | No | No |
| Built-in GPS | No | Yes | No | No |
| Feel on wrist | Very light, barely there | Slightly heavier | Jewelry-like, premium | Ultra-slim, lightweight |
| Model codes | FB410, FB412, FB414, FB420 | FB419, FB422 | FB418 | FB406, FB408 |
The surest way: flip your tracker over and find the FB code. If it is FB410, FB412, FB414, or FB420 — you have an Inspire. Done.
Which Inspire do I have specifically?
| Model Code | Full Name | Key difference |
|---|---|---|
| FB410 | Fitbit Inspire | Basic, no heart rate sensor |
| FB412 | Fitbit Inspire HR | Added continuous heart rate |
| FB414 | Fitbit Inspire 2 | Longer battery (10 days), Active Zone Minutes |
| FB420 | Fitbit Inspire 3 | Color display, stress tracking, Daily Readiness |
If you are thinking of upgrading from an older Inspire, the Inspire 3 is the current model — it added a color screen and significantly better health tracking. (Add Amazon affiliate link here)
Fitbit Time Keeps Going Wrong — How to Fix It
This is the most frustrating Fitbit issue for new users — and also the easiest to fix once you understand how it works.
Fitbit watches do not have an independent clock. They get their time from your phone through the Fitbit app. You cannot set the time manually on the watch itself.
Step 1 — Make sure the Fitbit app is installed and you are signed in
If you just reinstalled the app, sign in with your original email. Your Fitbit will not sync time correctly unless it is properly connected to your account.
Step 2 — Enable Bluetooth on your phone
The Fitbit app syncs time over Bluetooth. If Bluetooth is off — or if another device is interfering — the sync fails and the time stays wrong.
On iPhone: Settings → Bluetooth → toggle On On Android: Settings → Connected Devices → Bluetooth → toggle On
Step 3 — Open the Fitbit app and force a sync
- Open the Fitbit app
- Pull down on the Today screen to refresh
- Watch your Fitbit screen — the time should update within 30 seconds
Step 4 — Check your timezone setting
This is the most overlooked cause of wrong time. If your phone’s timezone is set incorrectly — or if you recently traveled — the Fitbit will show the wrong time even after syncing.
To fix:
- In the Fitbit app go to Today tab → your profile picture → App Settings
- Find Clock Display Time and make sure it is set to the correct format
- Your phone’s timezone should match your location — check this in your phone’s Date & Time settings
Step 5 — Restart your Fitbit
If time is still wrong after all of the above:
- Inspire 3: Press and hold the button on the side for 8 seconds until you see a smiley face
- Charge 6: Press and hold the button for 8 seconds
- Versa 4 / Sense 2: Hold the button for 10 seconds until the Fitbit logo appears
After restarting, open the app and sync again. The correct time should appear immediately.
If none of this works: Remove the device from your Fitbit account and re-pair it from scratch. Go to the app → your profile → your device → scroll to the bottom → Remove Device. Then set it up again as new.
Frequently Asked Questions
I lost the Fitbit app from my phone — is my data gone?
No — your data is saved to your Fitbit account, not your phone. Reinstall the official app from the App Store or Play Store (developer: Google LLC), sign in with the same email you used originally, and everything comes back. Your devices, history, and settings are all still there.
There are so many Fitbit apps — which one do I download?
Only one matters: the official app simply called “Fitbit” made by Google LLC. It has a teal/aqua diamond icon. Everything else in the store is a third-party app that cannot actually connect to or identify your Fitbit. Search “Fitbit” and check the developer name before downloading.
Can I identify my Fitbit if it is completely dead?
Yes. Remove the band and look at the back of the tracker — the model code is physically engraved there. You do not need power.
What if the Fitbit app shows a different device than what I actually have?
This happens if you previously owned a different Fitbit and did not remove it from your account. Go into the app’s Devices section, tap the three dots next to the old device, select Remove, and re-pair your current tracker.
Where exactly is the model number on older Fitbits like the Alta or Charge 2?
On older devices, the model code is printed on the back panel near the sensor area. It can be very small — use a flashlight and look closely or try a magnifying glass.
Does Fitbit still support older models?
Support varies. Google has gradually wound down support for devices released before 2019. Check Fitbit’s official support page for your specific model’s current status.
Where is the serial number on a Fitbit?
Your serial number is in the Fitbit app under Profile → Device → Device Information. It is also on the back of the device (may require removing the band) and on your original box or purchase receipt.
How do I know if my Fitbit is charging?
You should see a battery icon or charging animation on screen. If nothing appears, try a different charging cable, clean the contacts on both the device and cable with a dry cloth, and try again.
Can I identify my Fitbit by size or shape alone?
Partially. Combine screen shape, button type (physical button vs. capacitive groove), sensors on the back, and the model code on the back for a definitive answer. Shape alone can mislead you — the Versa 4 and Sense 2 look nearly identical from the front.
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?
4 Comments
what model is this Fitbit?
model fitbit “3F15F09850E1”
I think The serial number “3F15F09850E1” corresponds to a Fitbit Charge 4
I can not figure figure out which fitbit I have using your instructions. I want to set up the fitbit app but can not figure which to download. There are so many. i believe i have fitbit inspire but am unable to distinguish the difference. The time on my watch keeps going haywire and i cant figure out how to set it correctly and thought i wolf by the app but cant figure the appropriate app to download. At some point, I don’t l is qhat happened to the fit bit app I used to have on my phone but no linger have it.
Hi, thanks so much for reaching out — really glad you found the site.
Let me clear this up step by step.
Step 1 — Download the correct app
There is only one official app. On iPhone, search “Fitbit” in the App Store — the official one is simply called Fitbit, made by Google LLC, and has an aqua/teal icon. On Android, same thing — search “Fitbit” in the Play Store, developer is Google LLC. Ignore anything else that comes up.
Step 2 — Figure out if it is an Inspire
Inspire models are very slim and lightweight — they feel almost like wearing nothing. If yours looks like a thin band with a small vertical screen and no buttons on the side, it is almost certainly an Inspire. To confirm: flip it over and look for a code starting with FB. Inspire models are FB410, FB412, FB414, FB420. If you see one of those, you have your answer.
Step 3 — Fix the time
Once the app is installed and your Fitbit is connected, the time syncs automatically from your phone. You do not need to set it manually. Just make sure Bluetooth is on, open the app, and let it sync — the correct time will appear on your watch within a few seconds.
If the time keeps going wrong after syncing, it is usually a timezone setting issue. In the app go to Today tab → your profile picture → App Settings → and check that your timezone matches your location.
Hope this helps — feel free to reply if you get stuck anywhere.