Battery Status Checker

What this tool does

The Battery Status Checker reads your device’s battery through the browser’s Battery Status API and shows it clearly: the current charge level as a percentage, whether the device is charging or running on battery, the estimated time to a full charge, and the estimated time until empty. A visual battery indicator fills to match the level, and its colour shifts — green when the charge is healthy, amber in the middle, red when low — always paired with the percentage in text so the meaning never depends on colour alone.

The readout updates live. The browser’s battery object fires events when the level changes, when charging starts or stops, and when the time estimates change, and the tool listens for all of them, so the page tracks your battery in real time without a refresh.

When you would use it

You might check this before unplugging a laptop for a long stretch away from power, or while diagnosing a battery that seems to drain unusually fast — the live percentage lets you watch how quickly the level falls under a given workload. Developers building web apps use it to see what the Battery Status API actually reports on a given device and browser, and to confirm their code handles the case where the API is missing. It is also a quick way to verify a charger or cable is working: plug in and watch the charging state flip.

How to use it

1. Open the page in a supported browser. The battery is read automatically — there is no button to press and no permission prompt.
2. Read the indicator and the percentage. The fill level and colour reflect the charge; the text below states charging or discharging.
3. Watch it update. Plug in or unplug your device and the state, colour and time estimates change within moments.
4. Use Copy all to copy a plain-text summary of level, state and time estimates.

How to read the results

The charge level is the percentage of capacity remaining. The charging state says whether the device is plugged in and charging or running on battery. Time to full charge appears only while charging and estimates how long until 100 percent. Time to empty appears only on battery and estimates how long the current charge will last. Both times come from your operating system and can shift as your workload changes, so read them as a guide. If the charge is low and red, plug in; if a time estimate reads “not available”, that is normal right after plugging in or unplugging, while the system gathers data.

Browser compatibility

This is the important part. The Battery Status API is available only in Chromium-based browsers — Chrome, Edge, Opera and Brave — on desktop and Android. It has been removed from Firefox and is not implemented in Safari, including on iPhone and iPad, because the precise charge level can be used to help fingerprint and track users. That removal is a privacy improvement, not a defect.

So if you open this tool in Firefox or on an iPhone, it will show a calm, clearly worded message explaining that battery information is not available and why. That is the expected behaviour: the tool feature-detects the API and never throws an error or shows a blank screen. To read your charge level here, use a Chromium browser; otherwise your operating system’s own battery indicator is always the reliable source.

To explore what else your browser exposes, see the Browser Info Viewer and the Screen Resolution Checker. To test your camera use the Webcam Test, and to check location access see the Geolocation tool.

Privacy

Battery information is read on your device and shown only on this page. Nothing is uploaded, nothing is stored between visits and nothing is logged. Closing the tab discards it all.