ToolAct

Extract Audio from Video

Save an original audio track or convert it to MP3, right in your browser.

Your video and audio stay on this device. The processing engine is downloaded when needed; your media is never uploaded.

Choose a video

Drop one video here

MP4, MOV, MKV or WebM · One file at a time · Up to 200 MiB

200 MiB is this tool’s conservative per-file limit, not a browser limit. Processing needs extra memory; even smaller files may fail on low-memory devices. A desktop browser is recommended.

Select a video to get started.

Engine licenses and source code

Separate the soundtrack from a video

Video files usually contain separate streams for picture, audio and sometimes subtitles. This tool reads those streams locally and saves one audio track as its own file. It does not record your speakers or need microphone access.

Choose original audio to copy the encoded sound without another lossy encoding step. Choose MP3 when you need broader player compatibility. MP3 conversion decodes the source and encodes it again, so it uses more CPU and can reduce quality.

How to extract audio

  1. Choose one MP4, MOV, MKV or WebM file of up to 200 MiB. The audio engine loads only when you select a valid file.
  2. Wait for the audio tracks to appear. If there is more than one, select the language or track you want using the track details.
  3. Choose original audio, or select MP3 and a bitrate. Then select Extract audio.
  4. Preview the result if your browser supports its format, then download it. Leaving the page or removing the file clears the result.
  • Keep this tab open while processing. You can cancel loading or processing at any time.
  • Start with a short clip on phones or tablets. The 200 MiB product limit does not guarantee that every smaller file will fit in your device’s memory.

When this is useful

Listen to a recorded talkExtract the spoken track from a lecture or presentation you are allowed to use. MP3 is convenient for audio players; choose the correct track if the video includes several languages.
Keep the original soundtrackUse original audio when you want to avoid another lossy encode. An AAC track from an MP4 is saved as M4A; other codecs need a matching container.
Prepare audio for editingSeparate a camera clip’s sound for an audio editor. Supported little-endian PCM is saved as WAV and big-endian PCM as AIFF, without lossy compression. These files can be larger than a compressed audio export.

How local audio extraction works

A single-threaded FFmpeg WebAssembly engine runs inside a browser worker. It is loaded on demand from this site, with no third-party processing service. The selected video is read into the engine’s in-memory file system, inspected, and processed locally.

Original mode copies the selected stream into a compatible audio container. MP3 mode uses the LAME encoder and the selected bitrate; it keeps mono or stereo, and mixes multichannel audio down to stereo. Video and subtitles are omitted. Cancelling or leaving the page terminates the worker; temporary files and download links are released when they are no longer needed.

  • A filename extension identifies a container, not its internal audio codec. Two MP4 files can therefore behave differently.
  • Input data, WebAssembly memory and output data can coexist in memory. The 200 MiB input guard is a product safeguard, not a measured device capability or a promise of success.
  • Processing time depends on the source codec, duration, device and mode. The tool shows real processing stages rather than an estimated completion percentage.

Typical output formats

MP4 with AAC → M4A

Original mode copies the AAC audio into an audio-only MP4 container with the .m4a extension. There is no new audio encoding step.

WebM with Opus → Ogg

Original mode keeps the Opus packets and saves them in an Ogg container. Player support for this format varies.

MOV with PCM → WAV or AIFF

Original mode saves supported little-endian PCM as WAV and big-endian PCM as AIFF. Choosing MP3 instead creates a lossy file at the selected bitrate.

Frequently asked questions

Is my video uploaded anywhere?

No. The video and extracted audio are processed on your device. Your browser downloads the engine from this site on first use, but it does not send your media to a processing server. You do not need to grant microphone or camera access.

Does extraction change the sound quality?

Original mode does not re-encode the audio, so it avoids additional encoding loss. MP3 mode is lossy even at 320 kbps. A higher bitrate cannot restore detail that was already lost in the source.

Why is the original-audio download not always M4A?

M4A is an audio-only MP4 container, not a universal audio codec. AAC fits M4A, whereas other supported codecs may be saved as MP3, Ogg, WAV, AIFF, FLAC or their native audio format. If the source codec has no supported copy container, the tool offers MP3 conversion instead.

Which videos and browsers work?

The file picker accepts MP4, MOV, MKV and WebM. Actual support depends on the codecs in the file and the bundled FFmpeg build. Use a recent browser with WebAssembly and worker support; DRM-protected and damaged files cannot be processed. A desktop browser is recommended, and mobile memory limits can cause failures.

Why is there a 200 MiB limit?

This is a conservative product limit for this version, not the browser’s technical maximum. Browser processing needs memory for the input, engine and output at the same time. Even a smaller file can fail on a low-memory device; use a desktop application for long or large videos.

What if the video has no sound or several audio tracks?

A video without an audio stream produces a no-audio message. If several streams are present, select one from the track list. The tool saves one track at a time and does not combine languages. MP3 output mixes audio with more than two channels down to stereo.

What happens when I cancel or leave the page?

The processing worker is terminated and temporary media data is released. You can select the file again to start over. Download the completed audio before leaving; the page does not keep a history of your media or save the result for a later visit.

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