Browser Kitty
日本語
video

Video Audio Extractor

Select one audio track from a video and save it unchanged when supported, or convert it to M4A, MP3, or WAV.

View on GitHub
Local processing
About your filesFiles and content selected in this tool are processed in your browser and are not uploaded to a Browser Kitty backend.
Operation demo See the basic workflow in a short video.

About this tool

Video Audio Extractor saves one audio track from a video as a separate audio file. Supported AAC / ALAC / MP3 / Opus / Vorbis / FLAC streams can be copied without re-encoding, while M4A, MP3, and WAV conversion is available when you want a different output format.

For videos with multiple audio tracks, the app shows language, title, default-track information, codec, and other available details so you can choose one track. Video inspection, extraction, conversion, and result generation run in the browser without uploading the selected video to Browser Kitty.

Good for

  • Save only the audio from a video recorded on a phone
  • Extract meeting, lecture, or interview audio as MP3 or M4A
  • Choose one track from a video containing multiple languages or audio tracks
  • Extract audio without uploading the source video to an online conversion service

What it can do

Key capabilities available in this tool.

How to use

  1. Choose a video file or drag and drop it into the app.
  2. After inspection, if multiple audio tracks exist, review language, title, codec, and other details and choose the track to extract.
  3. Choose Keep original quality, M4A, MP3, or WAV.
  4. For M4A / MP3, choose a bitrate as needed; MP3 also lets you choose mono or stereo.
  5. Review the output filename and start Extract audio.
  6. Preview the result when the browser can play the format, then save the audio file.

Supported

  • Input: video containers such as MP4 / M4V / MOV, MKV / WebM, AVI, MPEG-TS / MPEG-PS, FLV, ASF / WMV, and 3GP when the bundled FFmpeg profile can inspect them. Support is not determined by filename extension alone.
  • Keep original quality: verified stream-copy paths include AAC→M4A, ALAC→M4A, MP3→MP3, Opus→OPUS, Vorbis→OGG, and FLAC→FLAC.
  • Conversion: M4A uses AAC at 128 / 192 / 256 kbps; MP3 uses LAME 4.0 at 128 / 192 / 256 / 320 kbps with mono / stereo selection; WAV uses signed 16-bit little-endian PCM.
  • Multiple audio tracks: when metadata exists, the app shows language, title, default disposition, codec, bitrate, sample rate, channels, and related details. One track is processed per run.
  • Runtime: the bundled FFmpeg WebAssembly profile is single-threaded and does not require SharedArrayBuffer or cross-origin isolation. Its CSP uses connect-src 'none'.

Limitations and notes

  • One audio track can be extracted per run. Batch extraction of all tracks and batch processing of multiple videos are not supported.
  • Audio-only input is outside this tool's purpose. A video with no audio track has nothing to extract.
  • AC-3 / E-AC-3 are not offered as verified Keep original quality outputs in the current profile. The app does not guess unverified stream-copy combinations.
  • Very large or long videos can run into WASM memory, output-size, device-performance, or free-storage limits.
  • If the browser cannot play the generated audio format, in-app preview is unavailable even though saving may still work. Audio trimming, joining, fades, volume adjustment, denoise, and similar editing are out of scope.

Frequently asked questions

Is my video uploaded to a server?

No. The hosted version first loads the application HTML, but inspection, extraction, conversion, and result generation run in the browser and the selected video content is not sent to Browser Kitty.

Can I extract audio without changing its quality?

For supported audio streams, yes. AAC / ALAC / MP3 / Opus / Vorbis / FLAC use verified stream-copy mappings so the compressed audio is not re-encoded. Unverified codecs are not offered in Keep original quality mode.

Can I choose among multiple audio tracks?

Yes. When several audio tracks are detected, available language, title, default-track information, codec, and related details are shown so you can choose one track.

Can I convert the extracted audio to MP3 or M4A?

Yes. M4A offers 128 / 192 / 256 kbps, MP3 offers 128 / 192 / 256 / 320 kbps, and WAV conversion is also available.

Can I save the result if the browser cannot preview it?

If the browser cannot play the generated format, the in-app preview is unavailable, but the audio file may still be saved when generation succeeded.

Offline version and source code

The root-level video-audio-extractor.html bundles FFmpeg JavaScript, WebAssembly, the browser runtime, and UI in one HTML file. Save it and open it directly in current Chrome / Edge to inspect video, extract or convert audio, preview supported results, and create output without runtime external networking.

View source on GitHub

Use together

Useful next steps and companion tools, organized around the workflow.

Inspect tracks and codecs Media Inspector Inspect container, codec, bitrate, sample rate, channels, metadata, and other media details before or after extraction. Edit extracted audio Audio Cutter & Joiner Trim or split extracted audio, or arrange several audio clips and join them into one file. Compress the source video Video Compressor When the goal is to reduce the source video itself rather than extract audio, adjust resolution and bitrate and compress the video.