Battery Health Test: Free Online Check Any Device Battery
Check the battery level and long term health of your phone, laptop, mouse, keyboard, headphones, or game controller free in your browser. Check this device directly, connect over Bluetooth to read an accessory battery, or use the manual estimator if a device cannot be read in browser.
No device connected yet. Click Check This Device for the device you are on now, or pair an accessory first and click Connect Bluetooth Device above.
Connect your controller to read a live battery level. Health trend needs several full charge readings spread across at least a week before it becomes meaningful.
Checking this device works only where the browser still exposes local battery status. Reading a Bluetooth accessory works in Chrome and Edge on desktop and Android. Safari and Firefox support neither, use the manual estimator below instead.
Manual battery health estimator
If your browser cannot read live battery data, or your device does not expose it, use this quick manual estimate instead. Compare your device current runtime against its original rated runtime to see how much capacity it may have lost, whether it is a phone, laptop, headphones, or a game controller.
How to test any device battery health
Choose your path
Testing the phone or laptop you are using right now, click Check This Device. Testing a separate accessory, pair it with your operating system Bluetooth settings first, then use Connect Bluetooth Device.
Allow access when prompted
For an accessory, a native device picker appears listing nearby paired devices that expose battery data. Select yours and allow access when prompted.
Read your battery level
The gauge shows the current charge instantly. Each reading is saved on this device so you can build a history over time.
Check back over time
Come back and read the same device again after each full charge over the coming weeks. Once you have enough full charge readings, a health trend appears.
What is device battery health
Battery level tells you how full a battery is right now. Battery health is a different question entirely, it describes how much total capacity that battery still holds compared to when it was new. A phone, laptop, or controller battery that shows 100 percent charged can still have lost real capacity, since 100 percent simply means full relative to its current maximum, not its original maximum. This is why this tool is often searched as battery health checker, device battery tester, or wireless battery test.
Level versus health
Battery level is a single snapshot in time. Battery health only becomes visible across many readings, comparing full charge peaks over weeks and months.
Why it matters
A phone that used to last all day and now needs charging by lunch, or a controller that used to last a full weekend and now needs nightly charging, both show measurable capacity loss even though the level reading still climbs to 100 percent.
Trend over single readings
One reading only tells you the charge right now. This tool emphasizes tracking full charge peaks over time, since that trend is what actually reveals aging.
Battery level ranges
Ready for an extended session with plenty of runtime left
Plenty of runtime for a typical gaming session
Plan to plug in before your next long session
Approaching shutoff, plug in soon to avoid interruption
Which devices can be read in browser
Not every device exposes its battery to a web page. Here is a practical compatibility guide covering phones, laptops, and Bluetooth accessories.
This device you are on now
Some browsers and operating system combinations still expose local battery status directly to the page. Where this is unavailable, most browsers have removed it for privacy reasons, use the manual estimator instead.
Bluetooth accessories
Mice, keyboards, headphones, smartwatches, and game controllers that expose the standard Bluetooth battery service can usually be read directly. PS5 DualSense, PS4 DualShock 4, Xbox Series controllers over Bluetooth, and recent 8BitDo controllers are common examples that work.
Usually does not work
Nintendo Switch Pro Controller, devices paired through a proprietary wireless dongle rather than Bluetooth, and most iOS devices do not expose battery data to a web page. Use the manual estimator for these.
Tips to extend any device battery life
- Keep the charge level between roughly 20 and 80 percent when possible, since staying at the extreme ends accelerates lithium ion aging on phones, laptops, and controllers alike.
- Avoid letting a device fully discharge to 0 percent repeatedly, and plug in when you reach the charge soon range instead of waiting until shutoff.
- Store an unused device at roughly half charge rather than completely full or completely empty for long term storage.
- Keep devices away from direct heat, since high temperatures speed up battery capacity loss more than normal use does.
- Use the charging cable and adapter recommended by the manufacturer, since third party chargers can sometimes deliver inconsistent power.
Healthy lithium ion batteries typically last from about eighteen months to a few years under normal use before capacity loss becomes very noticeable, whether in a phone, a laptop, or a game controller. Gradual decline is expected, sudden or fast decline is the signal to consider a replacement battery or a new device.
Test your other controller specs
Battery health is one part of overall controller performance. Check the rest of your setup with our other tools.
Gamepad Tester
Full button, stick, and trigger diagnostics in one interface. Open Gamepad Tester
Connection Stability Test
Check for wireless dropouts and signal issues that can look like a battery problem. Open Connection Stability Test
Input Latency Test
Measure response time, which can rise slightly as battery charge drops on some wireless controllers. Open Latency Test
Frequently asked questions
Why does this only work in Chrome and Edge?
Reading a Bluetooth device from a web page requires the Web Bluetooth API, which is currently only implemented in Chromium based browsers such as Chrome and Edge, including Chrome on Android. Safari and Firefox have not shipped this API.
The device picker shows nothing when I click Connect. What do I do?
Make sure the controller is paired with your operating system first and is currently powered on and connected, not just paired and off. Web Bluetooth reads already paired devices, it cannot start the initial pairing itself.
Does this test battery health or just battery level?
Both. The current level shows instantly on connection. Battery health, meaning capacity loss over time, only becomes clear once you have several full charge readings spread across at least a week, at which point a trend appears.
How accurate is the battery level reading?
It is only as accurate as the value your controller itself reports. Controllers estimate charge from voltage, which is not perfectly linear, so individual readings can vary by a small margin for the same real state of charge. Trends across many readings are more reliable than any single number.
My Switch Pro Controller does not appear. Is it broken?
No. The Switch Pro Controller uses a proprietary battery reporting method that standard Web Bluetooth cannot access. Check the battery indicator on the Switch home screen instead, or use the manual estimator on this page.
What counts as normal battery decline for a controller?
A slow, gradual drop in full charge peaks over many months is normal lithium ion aging. A fast or sudden decline, or a controller that no longer holds a useful charge after a short time, points toward a battery nearing the end of its useful life.
Will checking my battery repeatedly damage it?
No. Reading the battery characteristic uses a negligible amount of power. Normal use of your controller has far more impact on the battery than checking its level.
What happens if I switch browsers or devices?
Your saved reading history lives in the browser you used to record it. Switching to a different browser or computer starts a fresh history, so use the same browser consistently for the clearest long term picture.
Do I need to download software to test my controller battery?
No. This battery health test runs entirely in a supported browser. There is nothing to download and no account is required.
Can I use this on a phone or tablet?
Yes, Chrome for Android supports Web Bluetooth, so you can pair and read most controllers directly from a mobile device. iOS Safari does not currently support this feature.