Where does the recording go?

Nowhere. It is held as a blob in this tab, played through a local object url and dropped when the tab closes. The only way it leaves the browser is if you press Download.

Why does the browser ask for permission?

Reading a microphone requires an explicit grant by design, and it is asked for the first time you press Start microphone. If it was blocked earlier, the padlock in the address bar is where you allow it again.

What format is the clip saved in?

Whatever the browser can encode, which is usually WebM with Opus in Chrome and Firefox and MP4 in Safari. The panel names the format it used, and the download keeps the matching file extension.

Why does the bar barely move when I speak?

Usually the wrong input device is selected, or its gain is low in the system sound settings. Also check that automatic gain control is not fighting the test, and try again closer to the microphone.

Microphone Recorder

Microphone recorder

The microphone is opened straight from this page, and both the level and the recording stay in it. A clip is held in memory only, so you can play it back and download it, and it disappears when the tab closes.

Level—

Peak—

Input—

0:00

Reading the numbers

Level is the loudness right now in dBFS, where 0 is the loudest a digital signal can be and silence sits near -60.
Peak is the loudest moment since listening started. A peak that reaches 0 means the input is clipping, and turning the gain down will sound better than any repair afterwards.
A bar that barely moves usually means the wrong input device is selected, or the gain is set low in the system sound settings rather than in the browser.
Speech that sits between about -24 and -12 dBFS is comfortable for a call or a recording.
Record captures the same signal the meter shows. A fresh recording replaces the last one, and Discard throws it away without a trace on disk.

Learn

Microphone Recorder Guide

About this tool

Find out whether a microphone is picking anything up, and how loudly, then keep a clip of it. The browser opens the input and the level is measured on a bar with a peak marker, so a quiet headset or a muted laptop mic is obvious at a glance. Press Record and the same signal is captured, so the recording can be played back on the page straight away or downloaded as a file.

Questions

Where does the recording go?: Nowhere. It is held as a blob in this tab, played through a local object url and dropped when the tab closes. The only way it leaves the browser is if you press Download.
Why does the browser ask for permission?: Reading a microphone requires an explicit grant by design, and it is asked for the first time you press Start microphone. If it was blocked earlier, the padlock in the address bar is where you allow it again.
What format is the clip saved in?: Whatever the browser can encode, which is usually WebM with Opus in Chrome and Firefox and MP4 in Safari. The panel names the format it used, and the download keeps the matching file extension.
Why does the bar barely move when I speak?: Usually the wrong input device is selected, or its gain is low in the system sound settings. Also check that automatic gain control is not fighting the test, and try again closer to the microphone.