MP4 → MP3 Converter

Extract audio from lecture, seminar, and meeting videos to convert to MP3 format optimized for NotebookLM.
Noise reduction, voice enhancement, and volume normalization significantly improve AI transcription accuracy.
All processing is done in your browser - files are never sent to our servers.

Tip: Audio clarification and noise reduction make meeting recordings and workshop audio much easier to understand.

Drag & drop video file
or click to select
File Size -
Duration -
Video Codec -
Audio Codec -

Audio Optimization Settings

30%
Recommended: Removes low-frequency noise from air conditioners and fans. Reduces venue ambient sound.
Recommended: "Clarity Focus" improves speech intelligibility and enhances transcription accuracy.
-3 dB
Recommended: -3dB is the optimal level without distortion. The limiter prevents clipping while ensuring sufficient volume.
Recommended: File size estimate: About 60MB for 1 hour of audio (128kbps). 128kbps is recommended for long workshops.
Processing... Extracting audio...
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Audio Waveform Comparison

Before
After
※ Waveform changes visually confirm audio quality improvement

Frequently Asked Questions

Q: What video file formats can be converted?

Supports video formats supported by browsers including MP4, WebM, AVI, MOV, and MKV. For audio files (MP3, WAV, etc.), only optimization processing is performed.

Q: Are optimization settings necessary?

Yes, highly recommended. Noise reduction and voice enhancement significantly improve audio clarity, especially effective for conference room or workshop recordings.

Q: Why does processing take time?

Because video decoding, audio processing, and MP3 encoding are performed in the browser, processing time is proportional to video length. Expect about 5-10 minutes for a 1-hour video.

Q: Are there file size limitations?

Depends on browser and device memory, but files under 1GB are generally recommended. Larger files may affect performance.