What Should You Check When Buying a Used Smartwatch?

Check the activation lock and account status

The first thing to verify is that the watch is not tied to someone else's account. Activation lock prevents the watch from being paired to a new phone until the previous owner removes it. For most smartwatches, this means confirming that the watch has been unpaired and reset to factory settings. The watch should show a setup screen or be in a state where it is ready to pair. If the watch still shows a previous owner's account or asks for a password, it is locked. Learn how activation lock works.

If you buy a watch that is still locked, you may not be able to use it at all. Ask the seller to remove the watch from their account and to demonstrate that the device is fully reset. You should also confirm that the watch is not reported stolen. While you cannot easily check that, a watch that has been factory reset and shows no sign of a previous account is a good sign. The unpair and reset process is straightforward on most platforms, and a responsible seller should be able to do it before handing over the device.

Verify battery health and charging

Batteries degrade over time, so a used watch may not hold a charge as well as it did when new. Many operating systems include a battery health percentage in the settings menu. Ask the seller for a screenshot of that screen if it is available. If the battery health is below an acceptable level, you can expect shorter battery life and more frequent charging. For example, a watch that needs to be charged daily when it used to last two days may have a degraded battery. Understand battery health checks.

You can also ask the seller to show you the estimated battery life after a full charge, or test the watch yourself by letting it run for a day and observing the drain rate. If the watch drains extremely fast or shuts down while the indicator still shows a high percentage, the battery may need to be replaced. Replacement is not possible on many models, or it can be expensive and difficult. Read about battery replacement options to know what you are getting into.

Inspect the screen and exterior

Inspect the screen under bright light for scratches, cracks, or burn-in. Burn-in is especially a concern on AMOLED displays, where static images can leave permanent ghost marks. Look for any discoloration or dark spots. Touch responsiveness is also critical: try tapping and swiping across the entire screen to ensure there are no dead zones. AMOLED burn-in is a common issue on older watches, and a screen with burn-in can be distracting. Also check the scratch resistance of the glass; a few fine scratches may be acceptable, but deep gouges can affect visibility and touch sensitivity.

Examine the case and lugs for dents, corrosion, or signs of heavy impact. Make sure the straps attach securely and that the release mechanisms work. Water resistance is another factor. Seals and gaskets degrade over time, so a watch that was frequently used in water may have weakened protection. If you plan to swim with the watch, verify the water resistance rating and consider whether the watch shows signs of wear. Water resistance wears out, so a watch that was once waterproof may no longer be safe in water.

Test sensor and connectivity functions

A used watch should still have working sensors. The most common are the optical heart rate sensor, blood oxygen sensor, and possibly an ECG sensor. You can test many of these during a standard workout or through the health apps. For example, the ECG app on Apple Watch requires a snug fit and a clean back; if the recording is consistently inconclusive, the sensor may be faulty. Understand how the heart rate sensor works and what to expect from an ECG reading. Also verify that the watch can measure your heart rate reliably during exercise, as a failing sensor may give erratic readings.

GPS is another key sensor. Take the watch outdoors and see if it acquires a satellite lock within a reasonable time. A delay of two minutes or more may indicate a problem, especially on a clear day. Bluetooth and Wi-Fi connectivity should also be tested. Pair the watch with your smartphone and walk away to see if the connection drops. Bluetooth range is typically around 10 meters in open air, but walls can reduce that. GPS accuracy can vary depending on the environment, but a watch that cannot lock onto a signal at all is a red flag.

Confirm operating system update support

Smartwatches receive software updates for a limited number of years. A watch that is no longer receiving updates may lack security patches and new features, and some apps may stop working correctly. Check the manufacturer's website or the watch's settings for the latest OS version and compare it to the model's release date. For example, Apple lists which watch models are compatible with the latest watchOS; if your prospective watch is too old, it will not update. Learn about smartwatch OS updates to understand typical support periods.

Wear OS devices also have defined support windows, and some may receive major updates less regularly. A watch that is still receiving updates is safer and more useful long-term. If the seller cannot confirm that the watch has been updated recently, be cautious. You can also check the software update screen on the watch itself to see the current version. End-of-support signs include a lack of updates for over a year and the withdrawal of the watch from the manufacturer's compatibility list.

What to pick for your use

Questions

How do I check if a used smartwatch has activation lock?

Ask the seller to reset the watch and confirm it is no longer linked to their account. If you see the setup screen, it is ready to pair. Learn more about activation lock.

What battery health should I look for?

Batteries degrade over time; a higher remaining capacity is better. Check the battery health setting if available, and be wary if it is very low. You can also compare the watch's estimated battery life to its original specifications.

Can a scratched screen be repaired?

Some scratches can be polished, but deep scratches are permanent and may affect touch sensitivity. Consider the cost of the watch versus a replacement. Scratch resistance varies by screen material.

How do I test the sensors on a used watch?

Use the built-in health apps. For heart rate, start a workout and see if readings update. For GPS, go outside and check for a lock. For ECG, follow the app's instructions; if you get an error, the sensor may be faulty.

Which smartwatch platforms still receive updates?

Apple supports watches for several years with each new watchOS; Wear OS devices also have update schedules. Check the manufacturer's website for the current OS and model support.

Is it safe to buy a used smartwatch from a stranger?

Take the same precautions as with any used electronics. Meet in a safe place, verify the watch works, and check the serial number if possible to ensure it is not stolen. Preparing for resale can help you understand what to expect.