Battery Status Test
See your charge level, charging state and time remaining, live from the battery.
How to use the Battery Status Test
- Open the page — the battery details load on their own.
- Plug the charger in or out; the readings update instantly.
- The time estimates come from the device, not from us.
About the Battery Status Test
This reads your battery through navigator.getBattery() and shows charge level as a percentage and a bar, whether the device is charging or running on battery, the estimated time to full while plugged in, and the estimated time remaining while it is not. It is live: unplug the charger and the status flips on the spot, no reload needed, which makes it a quick way to confirm a charging port or cable is actually doing something.
Two honest caveats. First, browser support is split. Chrome and Edge expose battery information; Firefox removed the API and Safari never added it, both because a battery reading is a surprisingly good fingerprinting signal. On those browsers there is nothing to show, and the tool says which browsers do have it rather than sitting there empty.
Second, the time estimates come from your device, not from us. They are the operating system's own guess based on recent power draw, so they swing about as your workload changes and are often not reported at all, in which case a dash appears. Treat the percentage and the charging state as solid and the times as a rough guide. For the rest of what your hardware reports, see device info, or run the laptop and PC tests.
Frequently asked questions
Why does this show nothing in Firefox or Safari?
Firefox removed the Battery Status API and Safari never implemented it, both on privacy grounds, because battery level and drain make a device easier to fingerprint across sites. There is no workaround. Chrome and Edge still expose it, so try one of those if you need the reading.
How accurate is the time remaining?
It is your operating system's estimate, passed straight through. It is calculated from recent power draw, so it jumps around when your workload changes and can be wildly optimistic right after you unplug. Many devices do not report it at all, and you will see a dash instead.
Why is time to full or time remaining showing a dash?
Because the device did not provide a usable figure. Some hardware and some browsers report an infinite or zero value rather than an estimate, and the tool shows a dash rather than inventing a number.
Does this tell me my battery health or capacity?
No. The web API only exposes charge level, charging state and the two time estimates. Battery health, cycle count and design capacity are not available to a web page. For those you need the manufacturer tools or the built-in system reports.
Is my battery information sent anywhere?
No. The reading happens in your browser and is displayed on the page. Nothing is uploaded or stored.