How recording works
The recorder uses the browser's MediaRecorder API. When you click Record, the browser asks for microphone permission, then captures audio directly into memory as a WebM/Opus stream. Nothing is uploaded — the recording exists only in your browser tab until you download it.
WebM or MP3?
WebM/Opus is the native recording format — high quality and small files. If you need MP3 (for compatibility with older players or some editing software), click Convert to MP3 and the recording is re-encoded locally via ffmpeg.wasm.
Microphone permission
The browser will only allow recording on a secure (HTTPS) page and after you grant permission. You can revoke microphone access any time in your browser's site settings.