Skip to content
Lizely

Video to Audio Converter

Extract the audio track from a local video as an Opus WebM file without uploading the source.

Privacy: your files never leave your device. All processing happens locally in your browser.

How to use

  1. 1.Choose one supported local video with an audio track.
  2. 2.Select Extract audio and keep the tab open while the video is processed in real time.
  3. 3.Check the duration and file size, then download the Opus WebM audio file.

About Video to Audio Converter

Video to Audio Converter extracts the audio track that your browser can decode from a local video and records it as an Opus WebM audio file. The source stays in the current tab: Lizely does not upload the video, send its contents to an API, or retain the output. This makes the tool useful for pulling speech, music, ambient sound, or a reference track from a clip when WebM audio is suitable.

Choose one MP4, WebM, MOV, M4V, or Ogg file up to 500 MiB. The decoded video must be no longer than five minutes, no larger than 4096 pixels on either side, and no greater than 3840 × 2160 pixels in total area. These limits bound memory, playback time, and browser resource use. A filename or MIME type only identifies a possible container; the browser must still support the codecs inside it.

Extraction happens in real time. A one-minute video normally takes about one minute to process because the browser plays its media stream while MediaRecorder captures only the exposed audio track. The preview is muted during processing, but the captured stream still contains the video's audio when the browser supports media-element capture. A progress label follows playback time, and Cancel stops the current job.

The output is WebM audio with an Opus track, not MP3, WAV, AAC, FLAC, or a lossless copy of the original compressed packets. Re-encoding may change quality and file size. The tool targets a broadly useful local browser path without adding a large media dependency; it does not promise format support that the current browser cannot provide. Safari and some other browsers may not expose captureStream or a compatible MediaRecorder format.

A video with no audio track fails explicitly instead of generating a silent file. Decode errors, unsupported recorders, empty output, invalid duration, excessive dimensions, and canceled work also stop with a visible message. The generated WebM container is patched with the known media duration so downloaded files can report a finite timeline in compatible players.

Use content only when you own it or have permission to extract and reuse its audio. The tool does not bypass DRM, platform access controls, protected streams, remote URLs, or copyright restrictions. For long recordings, lossless production work, multichannel preservation, precise trimming, or a specific delivery codec, use a dedicated desktop audio editor and verify its export settings.

Methodology & sources

Validate a bounded local file and decoded dimensions, call HTMLMediaElement.captureStream after metadata loads, require at least one audio track, create an audio-only MediaStream, and record it with the first supported Opus WebM MIME type at 128 kbps. Play from time zero to ended, collect nonempty MediaRecorder chunks, insert the measured duration into the WebM Segment Info element with the shared audited duration writer, and expose the result through a revocable Object URL.

Frequently asked questions

Is my video uploaded?
No. Decoding, playback capture, recording, and download generation happen in the current browser tab.
Why is the output WebM instead of MP3?
The tool uses the browser's built-in MediaRecorder and an Opus WebM format when supported. MP3 encoding would require a separate codec dependency.
Why does extraction take as long as the video?
The browser captures the media element during playback, so processing runs in real time.
Why does a supported extension still fail?
Containers can contain different codecs. Your browser must be able to decode the specific video and expose its audio track.

Related tools