The short version
- 01Put it on a wall charger for a full hour before concluding anything at all.
- 02Clean the charging contacts, which is the most common cause of no charge.
- 03For sync trouble, restart the tracker, then cycle Bluetooth for three seconds.
- 04Check the app has background, Location and Nearby Devices permissions.
- 05Rule out focus modes, sleep mode and an open conversation before notifications.
- 06Check how the band is worn before believing the heart rate sensor has failed.
Start here
Work out which part stopped, not which brand you own
Fitness trackers fail in five places and the fixes barely overlap: it will not charge, it will not sync, notifications stopped, the screen is blank or unresponsive, or the readings look wrong. Establish which one you have before doing anything — a tracker that will not charge and one that will not sync share no steps at all. Start by putting it on the charger for a full hour, because a flat tracker and a dead one are indistinguishable on the wrist.
Applies to: Fitness trackers and smartwatches generally. The documented steps cited here come from Fitbit's guidance in Google's help centre and Apple's for Apple Watch, because those are what we can source; the diagnostic split applies to any tracker, but check your own manufacturer for exact menu paths.
Which part has stopped?
Almost every fitness tracker problem is one of five, and almost every piece of advice online mixes them together. This page is the sorting step: it tells you which of the five you have, what the first move is for each, and where the detailed guide lives. The general principles hold across brands because the hardware is similar — small contacts, a Bluetooth link to a phone, a phone app that has to be allowed to run — but the exact menus differ, so the brand-specific guides carry the paths.
Blank screen, no response at all
Has it had a full hour on a charger?
Charge it firstIt works but the app shows old data
Is Bluetooth holding and the app allowed to run?
Fix the syncNotifications stopped arriving
Is something suppressing them by design?
Check the rulesSteps or heart rate look wrong
Is it worn where the sensor can read?
Check the fit1. Dead or just flat — and why you cannot tell
A tracker with a blank screen gives you no information. It could be completely discharged, it could be charging badly, or it could have failed. The only cheap way to separate those is to put it on the charger and leave it alone for a full hour, which is what Google's guidance for a Fitbit that will not charge asks for.
The thing that stops most trackers charging is not a fault at all. They charge through small metal contacts that sit against your skin all day, collecting sweat, oil and sunscreen, and the film that builds up is usually invisible. Google's documented fix is to clean the gold dots on the device and the pins on the charger with a cotton swab and rubbing alcohol — and, for stubborn buildup, to rub the contacts firmly with a pencil eraser, brushing every crumb away afterwards.
Charge from a wall outlet rather than a laptop port or a hub, because a port that has gone to sleep supplies nothing and looks identical to a broken tracker. And resist checking it every few minutes: lifting it off breaks the contact you just cleaned.
If an hour on a known-good charger produces nothing at all, that is the point at which the problem is worth escalating — and the detailed charging guide covers the sprung-pin check and the on-charger restart that revive a surprising number of apparently dead devices.
Do this before anything else. Half the trackers people believe are broken are flat, and a flat tracker cannot sync, notify or record either — so fixing power first can resolve what looks like four separate problems.
2. It works, but the app is showing yesterday
A tracker that records on the wrist but never reaches the phone has a link problem, not a device problem. Google's sequence for a Fitbit that will not sync is worth following in order, because each step is more disruptive than the last: restart the tracker and wait for the clock face, then sync manually from the app, then reset Bluetooth by turning it off, waiting at least three seconds and turning it back on, then restart the phone.
The three seconds matter more than they look. Toggling Bluetooth instantly often restores exactly the broken state you were trying to clear, which is why a quick flick of the switch so rarely helps.
Two causes are invisible from the tracker's side. Google asks you to confirm the app's Location and Nearby Devices permissions are enabled, and — separately — that the app is allowed to run in the background. Phones switch background activity off on their own to save battery, which produces the distinctive pattern where data syncs the moment you open the app and never in between.
The other one catches households rather than individuals: Google's first step is to uninstall the app on other devices and unpair the tracker from their Bluetooth settings. A tracker paired to a partner's old phone in the same house can be claimed by it, and your phone will never get a clean connection.
3. Notifications stopped, and most of the time nothing is broken
This is the category where the answer is usually that the tracker is behaving exactly as designed. Google's documentation lists several conditions under which notifications simply will not arrive, and none is a fault: the phone must be within 30 feet of the device, and you will not get notifications with focus, do not disturb, quiet hours or driving mode on. Do Not Disturb and sleep mode on the tracker itself do the same.
The one that catches almost everyone is the open-conversation rule — you will not get a text notification for a conversation you already have open on the phone. That produces the very specific complaint that texts stopped while everything else still works, and it is not a bug.
Sleep mode is the quiet one. A tracker set to enter sleep mode on a schedule suppresses notifications every night and morning exactly as configured, and there is nothing to see from the outside.
Work through those before touching Bluetooth. If none applies, the phone's own settings come next — the tracker only shows what the phone hands it, so a notification that never appears on the phone's lock screen has nothing to mirror.
Check the suppression rules first. They account for more reports than every technical fix combined, and they cost a minute to rule out.
4. When the numbers look wrong
Step counts and heart rate depend on where the device sits. Optical heart rate sensors read light reflected from the skin, so a band worn loosely, or over a wrist bone, or slid far down the hand, produces readings that are erratic rather than absent — which reads as a broken sensor and usually is not.
Battery-saving settings are the other common cause of data that looks wrong. Apple documents that for outdoor walking, running and hiking workouts you can have the watch take fewer GPS and heart rate readings to extend battery life on long sessions. That is a real trade: a setting enabled for battery reasons produces coarser data, and someone who did not enable it deliberately will read the result as a fault.
Before concluding anything, check the device has actually synced. Data that looks missing is very often data that is still sitting on the tracker, which puts you back in section 2 rather than here.
5. Battery life that collapsed rather than stopped
A tracker that still works but no longer lasts is a different problem from one that will not charge, and it has a different first question: did it change suddenly, or has it declined over a year or two?
A sudden change usually follows a software update, and Apple's guidance for the Apple Watch is explicit about this — wait several days after an update before reassessing, because background work continues after the install finishes. Acting during that window is how people end up crediting whatever setting they changed last.
A gradual decline is the battery ageing, and no setting reverses it. Where the device reports a maximum capacity figure, that is the number to look at before spending any more time on configuration.
In between those, the usual levers are the ones that run continuously: an always-on display, a connection working harder than it needs to, and workouts taking full sensor readings. Apple notes that a weak signal costs more battery than a strong one, which is the reverse of most people's intuition and worth knowing before blaming the device.
6. What to establish before contacting anyone
Five answers cover almost every version of this, whichever brand you own. Does it respond after a full hour on a wall charger? Does the app show current data, or old data? Is it every notification or only some? Does it behave the same after a restart of both the tracker and the phone? And did anything change — an update, a new phone, a new case — just before it started?
Work them in that order, because each is cheaper than the next and the early ones make the later ones unnecessary. A flat tracker fails every one of the other tests, so establishing power first saves you from diagnosing four problems that do not exist.
Brand-specific menus are where this page stops being useful, and the linked guides take over. The manufacturer's own support site is the right source for exact paths — those move between app releases far faster than the principles do.
Frequently asked questions
How do I fix a fitness tracker that won’t turn on?
Clean the charging contacts and give it a full hour on a wall outlet before concluding anything. Google's guidance for Fitbit is to clean the gold dots and charger pins with a cotton swab and rubbing alcohol, and to use a pencil eraser for stubborn buildup. A deeply flat tracker shows nothing for a long while.
Why won’t my fitness tracker sync with my phone?
Usually the Bluetooth link or the app's permissions. Google's order is to restart the tracker, sync manually, turn Bluetooth off for at least three seconds and back on, then restart the phone. Also confirm Location and Nearby Devices permissions, and that the app may run in the background.
Why did my tracker stop showing notifications?
Most often because something is suppressing them by design. The phone has to be within 30 feet, and focus, do not disturb, quiet hours or driving mode all stop them — as do Do Not Disturb and sleep mode on the tracker. You also won't get a text notification for a conversation already open on the phone.
Why is my heart rate or step count wrong?
Check how it's worn first. Optical sensors read light reflected from skin, so a loose band or one sitting over the wrist bone gives erratic readings rather than none. Battery-saving modes also reduce how often sensors sample — Apple documents fewer GPS and heart rate readings for long workouts.
My tracker's battery life suddenly got worse. Is it broken?
Not necessarily. If it followed a software update, Apple's guidance for Apple Watch is to wait several days before judging, because background work continues after the install. A gradual decline over a year or more is the battery ageing, which no setting reverses.
Does this apply to my brand of tracker?
The diagnostic does — every tracker charges through contacts, links to a phone over Bluetooth, and depends on an app that has to be allowed to run. The exact menus don't. The steps cited here are Fitbit's and Apple's because those are documented; check your own manufacturer for paths.
Sources and review notes
Checked on . Compiled by Glitchary from Google's Fitbit help centre guidance on charging, syncing and phone notifications, and Apple's guidance on Apple Watch battery life. Those are the brands whose documentation we can cite; the five-way split is editorial and applies more broadly, but menu paths differ by manufacturer and app release. The explanation of why optical heart rate sensors are sensitive to fit is editorial. Glitchary is independent of Google, Fitbit and Apple.