Reads the battery a Switch Pro Controller or a Joy-Con reports, on a computer, with nothing to install.
These are the numbers the controller reports about itself. The colours are the ones it was made in, stored inside it; a replacement shell does not change them.
This is a Switch 2 controller. It talks to a computer in a different way — Bluetooth LE and a USB channel browsers do not open to WebHID — so this page can name it but not read its battery. Check it on the Switch 2 under Controllers.
Medium charge
On battery
3.80 V
3.3 V4.2 VThe standard language input devices speak to a computer, and the browser feature that lets a page read it directly. It exposes what the device itself reports, not what a driver decided to show.
Pair the controller with Windows or plug it in, open this page in Chrome, Edge or Opera and press “Connect controller”. The level appears within a second, with the voltage under it, and next time the page reads it without asking.
Windows reads battery levels from the standard Bluetooth battery report. Nintendo controllers keep theirs inside their own reports and answer only when asked in their own protocol — which a browser with WebHID can do.
Yes. Pair each Joy-Con with the computer (hold the small sync button on its rail), then connect them here one after the other. Both appear on one card, left and right, each with its own level.
The page opens the controller through WebHID and asks it, in its own protocol, what it is: its type and firmware, the colours it was made in, and its battery voltage. Every answer carries the controller’s battery byte — one of four levels above empty, a charging bit and whether a cable powers it. The voltage comes from a second request every few seconds; Nintendo’s four levels are fixed voltage ranges between 3.3 V, where the controller turns itself off, and 4.2 V, where it stops charging, and the scale under the cell shows where in its band the battery sits. A wired controller first gets the short USB handshake every driver sends.
Measurement boundary: Four levels and a voltage are all the controller reveals: battery health and charge cycles are not in any report, and the voltage sags under load, so treat it as a position, not a percentage. Switch 2 controllers talk over Bluetooth LE and a USB channel WebHID cannot open, so they are named but not read. Only one app can hold a controller at a time, so close Steam, BetterJoy or an emulator first.
Full, medium, low and critical, then empty. The cell lights one bar per level — the controller’s own resolution, the one the console’s battery icon shows too.
From 3.3 V, where the controller switches itself off, to 4.2 V, where charging stops. Full is 3.9 V and above, medium 3.76–3.9 V, low 3.6–3.76 V, critical below. Rumble and the motion sensors make it dip for a moment.
“Charging” needs a cable or the console. “Powered by the cable” means a cable is attached but the controller is not charging; on a Pro Controller that is usually “charged”.
The body, button and grip colours are written into the controller at the factory. They are what the drawing shows, and they stay the same if the shell is replaced.
Check that it is paired in Windows Bluetooth settings (or plugged in) and awake — press a button first. Joy-Con are two devices: pair and connect each one. The browser must be Chrome, Edge or Opera on a computer.
Steam (with Switch controller support on), BetterJoy, DS4Windows and emulators can take the controller for themselves. Close them, or turn the Steam option off, and connect again.
Unplug it, plug it back in and connect again: the USB handshake works once per connection, and another app may already have done it. A charge-only cable carries no data at all — try another cable.
Joy-Con go to sleep when nothing is pressed. Press a button: the page picks it up again when it reconnects.
Open this page in Chrome, Edge or Opera, pair the controller with Windows or plug it in, and press “Connect controller”. The level, the charge state, the battery voltage and the firmware appear at once, with nothing to install.
On the Switch, open Controllers from the HOME Menu: the battery icon under each controller shows its level. On a computer, pair each Joy-Con by holding the sync button on its rail, then connect both here — they share one card, left and right.
No controller in the Switch family reports a percentage — not to the console and not to a computer. It reports one of four levels, and this page adds the battery voltage, which shows where inside that level the battery is.
Nintendo states about 40 hours on a full charge, depending on the game, and about 6 hours to charge it fully. Watch the voltage here over a session to see how fast your own controller drops.
Not yet. Joy-Con 2 and the Switch 2 Pro Controller use Bluetooth LE and a USB channel that browsers do not open to WebHID, so the page recognises them but cannot read their battery. Check them on the Switch 2 under Controllers.
Pads that present themselves as a Pro Controller in Switch mode, such as 8BitDo’s, answer the same requests and show a level. Some do not report the cable, so their charge state can read as on battery. Wired pads from PowerA, HORI and PDP send no battery at all.
Yes. The browser asks once and exposes only the controller you pick. The page sends the same read requests the console and Steam send and changes none of the controller’s settings; nothing leaves your computer.
Move from observation to a narrower diagnostic without losing context.
Read the battery of a DualSense, DualSense Edge or DualShock 4 on a computer with nothing to install: the charge state, the 10% band the controller reports, the time left measured on your own pad, and its firmware version.
02Watch every button, stick and trigger light up on a drawn PS5, Xbox or Switch pad, then test vibration, report rate and stick circularity — nothing to install, nothing uploaded.
03Measure the observed center offset, maximum movement and stability of both analog sticks with a repeatable browser test.
04 DesktopRead the raw HID reports of a DualSense or DualShock 4: stick centres to the byte, drift percentage, gyro bias, report rate, battery and touchpad, read-only over WebHID.
I answer from this site only — the 28 browser tests, the controls library for 46 games, the sensitivity converters and the two games. I can tell you which page to open, how a tool works and what its result means.
I will not guess. If something is not on the site, I will say so.
Answers come from this site's pages.