Live Battery Level
See your exact battery percentage update in real time, with a large visual gauge that changes color as it drops from green to amber to red.
Battery Test
Check your phone or laptop battery in real time — live level, charging status, drain rate, voltage, and estimated health. All from your browser, no app needed.
Ready to start
Level
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Status
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Drain Rate
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Health
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Battery API Not Supported
Your browser doesn't expose the Battery Status API for privacy reasons. This is common on iOS Safari and Firefox. You can still read the current level from your device's status bar. Try Chrome or Edge on Android or desktop for the full experience.
Start the test to see live drain data
Why It Matters
The Battery Test Built for Every Device
A fast, browser-based battery test that works on phones, tablets, and laptops — with real-time monitoring and a live drain-rate chart.
Charging Detection
Instantly detect if your device is charging, see the estimated time to full charge, and confirm your charger is delivering power correctly.
Drain Rate Analysis
Measures how fast your battery drops over time and charts it live. High drain rates often signal background apps, aging cells, or heavy screen use.
Health Estimate
Combines level stability, drain rate, and voltage readings to give you a rough health score — useful for checking a used phone before buying.
Live Drain Chart
Watch your battery percentage plotted on a live chart over a 5-minute window so you can spot sudden drops or unusually fast drain instantly.
100% Private, Runs Locally
Everything runs client-side using the standard Battery Status API. Nothing is uploaded, stored, or shared — closing the tab clears all data.
The Process
How to Test Your Battery Online
Four steps to check your battery level, health, and drain rate — all without installing anything.
Start the Test
Tap "Start Battery Test". Your browser reads your battery through the Battery Status API — no permission popup required on supported browsers.
View Live Data
Your current level, charging status, and time estimates appear immediately — with a large visual gauge at the top of the screen.
Watch the Drain
Keep the tab open for a few minutes. The live chart plots your level over time and calculates an accurate hourly drain rate.
Review Results
The sidebar shows all six diagnostic checks — API access, level readability, charging detection, drain rate, health estimate, and voltage stability.
Use Cases
Who Needs a Battery Test?
From checking a used phone to diagnosing unexpected shutdowns, this test covers every battery scenario.
Used Phone Buyers
Verify before you pay
Check drain rate on the seller's device
Confirm charging works normally
Spot signs of a worn-out battery
Performance Diagnosers
Find power-hungry issues
See if drain rate is unusually high
Correlate with background apps
Test before and after phone updates
Everyday Users
Know your battery
See exactly how fast it drains per hour
Confirm charging time to full
Get a quick health estimate
FAQ
Battery Test — Common Questions
Everything you need to know about testing your phone or laptop battery online.
Open this page on your phone or laptop browser, tap "Start Battery Test", and allow the browser to access battery information when prompted. The live test shows your battery level, charging state, drain rate, and estimated health — no app or download required.
The test measures your battery level, charging state, discharge rate, and voltage to estimate overall health. A fast drain rate or unstable voltage often indicates a degraded battery that may need replacement. For an exact capacity reading, compare the displayed percentage against a full 0-100% charge cycle.
Yes. The battery test works on any modern mobile browser, including Safari on iPhone and Chrome on Android. Some older iOS versions restrict detailed battery data, but level and charging status still display correctly.
No. This entire battery test runs locally in your browser using the Battery Status API. No data leaves your device, nothing is stored on a server, and closing the tab clears everything from memory.
Phone batteries change level slowly — usually 1% per few minutes when idle. The test tracks changes in real time and calculates the drain rate over a monitoring window. For best results, run the test for a few minutes with the screen on.
A typical modern smartphone drains around 5-10% per hour during light use, 10-20% per hour during active use, and 20%+ per hour during heavy gaming or video streaming. Rates significantly above these may indicate an aging battery or a power-hungry app.