WhisperWeb is a free transcription tool that runs in the browser: it executes OpenAI's open-source Whisper speech recognition model on your own device, so recordings are not uploaded. It accepts MP3, WAV, M4A, MP4, MOV, WebM and more, or a microphone recording. You can check and correct the text and timestamps before exporting, then download TXT, SRT or VTT. No sign-up; up to 200 MB or 20 minutes per file.