FLV to MP3 Converter
Convert FLV to MP3 free — no upload, no signup
To convert FLV to MP3, drop your FLV video into the box below and click Convert. Fylo converts with ffmpeg running inside your browser, so nothing is uploaded and there's no signup or watermark. Rescue the audio from old Flash video files.
Drop audio files here
or tap to browse · paste with Ctrl+V · add many at once
Your files never leave your device
Advanced
How to convert FLV to MP3
Add your FLV videos
Drag and drop FLV files into the box or tap to choose them. The converter engine (about 31 MB) downloads once, the first time you convert.
Pick a bitrate
192 kbps suits music and 128 kbps or less suits speech. Sample rate and mono/stereo are under Advanced.
Convert and download
Click Convert, then download each MP3 file or all of them as one ZIP.
Why convert FLV to MP3?
Old FLV downloads of music, interviews and lectures can't play in browsers anymore. Extracting MP3 keeps the content usable.
What happens when you convert FLV to MP3?
AAC or MP3 audio in the FLV is decoded and saved as MP3.
How does Fylo convert FLV to MP3?
Fylo decodes the soundtrack of the FLV (usually AAC) with ffmpeg compiled to WebAssembly and encodes it with the LAME MP3 encoder at 192 kbps (adjustable from 96 to 320 kbps). The video stream is skipped entirely, which is why extraction is fast — the MP3 is a fraction of the video's size. The original sample rate and channel layout are kept unless you change them under Advanced.
What's the difference between FLV and MP3?
FLV (Flash Video) was introduced with Flash Player 6 and 7 in 2002–2003 and became the format behind early YouTube, news sites and video portals. Later FLVs usually contain H.264 video and AAC audio — the same codecs as MP4.
MP3 (MPEG-1 Audio Layer III) was developed largely at Germany's Fraunhofer Institute and standardised in 1993. It removes sounds the ear is unlikely to notice — a technique called perceptual coding — so a 3-minute song takes about 4 MB at 192 kbps instead of about 32 MB as WAV. The last MP3 patents expired in 2017, so it's now free to use.
Learn more: FLV format guide · MP3 format guide
| Property | FLV | MP3 |
|---|---|---|
| Type | Video | Audio |
| Contains | Video (H.264, Sorenson Spark, VP6) + audio (AAC, MP3) | Audio only, lossy |
| Developed by | Macromedia / Adobe | Fraunhofer IIS / MPEG |
| Introduced | 2003 | 1993 |
| Compatibility | VLC and some desktop players; RTMP live-streaming tools | Universal |
| Best for | Old Flash archives, RTMP streaming workflows | Music and podcasts on any device |
Frequently asked questions
Can browsers play FLV?
No — that's why extracting the audio (or converting to MP4) helps.
Does it take long?
No, only the audio is processed.
Is my FLV file uploaded to a server?
No. Fylo runs ffmpeg, the same engine used by professional video tools, compiled to WebAssembly inside your browser. Your FLV file is read directly from your device and never sent anywhere.
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