How-to guide
How to extract audio from an FLV file
FLV is Adobe's Flash Video container — what a decade of Flash-era web video (YouTube pre-2010, Ustream, Twitch recordings before HLS) was saved in. VideoSplit reads FLV without needing the long-dead Flash Player plugin, because modern browsers still know how to decode its audio streams.
FLV audio is usually MP3 or AAC. The decode path in modern browsers is reliable, but very old FLV files from Flash 6-era tools sometimes have truncated headers — if one fails, try remuxing with ffmpeg to MP4 first.
Step-by-step
- Open VideoSplit.io. No Flash plugin needed. Any modern browser works.
- Drop the .flv file. Drag and drop onto the upload area.
- Pick WAV or MP3. If the source is already MP3 audio (common on FLV), WAV export gives you a clean PCM decode; MP3 export re-encodes at 320 kbps.
- Download the extracted audio. Saves to your Downloads folder under the original filename.
Tips for better results
- F4V is Adobe's successor format to FLV — VideoSplit reads it the same way.
- If the FLV was recorded from a live stream that dropped packets mid-broadcast, the audio may have gaps; those gaps carry over into the export.
- Screen recordings made with Screenflow or Camtasia before 2012 are often FLV — extraction works with no special steps.
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