Webcam and Microphone Test

Grant camera and microphone access and you get a live preview plus an input level meter. Speak normally: the meter should sit around the middle of its range and peak without reaching the clipping marker. A flat meter means the wrong input is selected, so switch it in the dropdown.

Nothing is recorded, transmitted or stored. The video stays in the page and the audio is measured frame by frame in WebAssembly; press Stop, or close the tab, and the browser turns the camera light off.

This is the one tool here that a browser may refuse to run from a file on disk. Camera permissions are attached to a web address, and a page opened directly has none. Firefox will still ask and allow it, but Chrome, Edge and Brave refuse before any prompt appears. Opening the page from a web address, including a local one, works everywhere.

How to use it

Press Start and allow camera and microphone access when the browser asks.
Check the preview, then speak and watch the level meter respond.
Switch devices in the dropdowns if the wrong one is selected, then press Stop.

Questions

Is my video recorded or uploaded?

No. The stream is attached to a video element in this page and never leaves your device. There is no server to upload it to, and the meter is computed from the audio in your browser.

Nothing happens when I press Start. Why?

Check the address bar. If it shows a file path rather than a web address, Chrome, Edge and Brave will refuse before showing a prompt: a permission has to belong to a web address, and a page opened from disk has none. Firefox is the exception and will ask normally. Serving the page over http or https fixes it in every browser.

The browser is blocking my camera. What now?

Click the padlock in the address bar and allow camera and microphone for this site, then reload. On macOS also check System Settings › Privacy & Security. Remember that only one application can hold the camera at a time, so quit any video call already running.

What should the level meter show?

Normal speech should push it to somewhere around the middle, with peaks well short of the clipping marker. Constant clipping means the input gain is too high; a barely-moving meter means it is too low, or the wrong microphone is selected.

Why is the level in negative numbers?

That is dBFS: decibels relative to the loudest signal that fits, which is 0. Everything quieter is negative, so −20 dBFS is a healthy speaking level and −60 is close to silence.

Your data stays on your device

Everything above runs inside your browser as WebAssembly compiled from Rust. Nothing you type is uploaded, logged or stored on a server. There is no server. You can load this page once, go offline, and it still works.