FLV to WebM Converter
Convert FLV to WebM free — no upload, no signup
To convert FLV to WebM, 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. Turn Flash videos into WebM for modern web pages.
Drop videos here
or tap to browse · paste with Ctrl+V · add many at once
Your files never leave your device
If the video already uses codecs that fit the new format, Fylo repackages it instantly with no quality loss.
Advanced
How to convert FLV to WebM
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.
Choose quality (optional)
Balanced quality suits most videos. If the codecs already fit WebM, Fylo repackages the file instead of re-encoding it, with no quality loss.
Convert and download
Click Convert, then download each WebM file or all of them as one ZIP.
Why convert FLV to WebM?
Sites that once used Flash players can replace FLV files with WebM for the HTML5 video tag.
What happens when you convert FLV to WebM?
The video is re-encoded to VP8 and the audio to Vorbis. For the widest device support, MP4 is usually the better replacement.
How does Fylo convert FLV to WebM?
Fylo reads the FLV with ffmpeg compiled to WebAssembly and writes VP8 with Vorbis audio, using libvpx's real-time preset so encoding stays practical in a browser. FLV's usual codecs (H.264, Sorenson Spark, VP6) can't go into WebM as-is, so the video is re-encoded. Speed depends on your device: short phone clips take seconds, while on our slow test PC a 2-minute 1080p video took about 10 minutes. Only the first video and audio track are kept, and the original resolution is preserved unless you pick 1080p, 720p or 480p under Advanced.
What's the difference between FLV and WebM?
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.
WebM was announced by Google in 2010 as an open, royalty-free alternative to H.264 for HTML5 video. It's a subset of Matroska restricted to VP8, VP9 or AV1 video and Vorbis or Opus audio. Browser screen recorders and many web tools save WebM by default.
Learn more: FLV format guide · WebM format guide
| Property | FLV | WebM |
|---|---|---|
| Developed by | Macromedia / Adobe | |
| Introduced | 2003 | 2010 |
| Typical video codecs | H.264, Sorenson Spark, VP6 | VP8, VP9, AV1 |
| Typical audio codecs | AAC, MP3 | Vorbis, Opus |
| Plays in web browsers | No (Flash Player ended in 2020) | Yes — Chrome, Edge, Firefox, Safari 14.1+ |
| Compatibility | VLC and some desktop players; RTMP live-streaming tools | Browsers, Android; limited in editors and on iPhone apps |
| Best for | Old Flash archives, RTMP streaming workflows | Royalty-free web video, screen recordings |
Frequently asked questions
Can I replace Flash video on my site?
Yes — use MP4 or WebM with the HTML5 <video> tag.
How long does it take?
Short clips take seconds; longer videos take longer.
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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