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MP4 to FLV - Online Video Converter
Convert MP4 to FLV online. Private, client-side - no uploadrequired. Batch conversion, quality presets, codec control.
Convert MP4 to FLV
Drop MP4 video here or click to select
MP4
FLV (Sorenson Spark / MP3)
About MP4 to FLV
Convert MP4 to FLV. MP4 pairs H.264 video with AAC audio in the ISO base media container. FLV is Adobe's Flash-video container carrying Sorenson Spark or H.264 streams. Flash-era players are gone, so convert for current browsers..
Why convert MP4 to FLV?
- Smaller files with FLV lossy compression.
- Keep animation and transparency where supported.
- Private, no upload - runs in your browser.
MP4 vs FLV
| Animation | Yes | Yes |
|---|---|---|
| Transparency | No | No |
| Compression | lossy | lossy |
| Typical use | MP4 pairs H.264 video with AAC audio in the ISO base media container. | FLV is Adobe's Flash-video container carrying Sorenson Spark or H.264 streams. |
When not to convert MP4 to FLV
- Skip FLV for archival masters: lossy compression discards detail, so keep the MP4 original.
- Keep a master copy: repeated exports stack small losses, so archive MP4 before batch FLV shares.
Limits
Starting point: MP4 - H.264 video with AAC audio in one file. H.264 has no alpha channel, so transparency is dropped. Flash-era players are gone, so convert for current browsers. Encode FLV (Sorenson Spark / MP3) from MP4 at a bitrate near the source, and confirm the audio track before converting.
How conversion works
Conversion runs entirely in your browser with FFmpeg WASM. Files never leave your device.
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FAQ
How do I convert MP4 to FLV?
Drop your MP4 file onto this page, choose quality and codec settings, then click Convert. The result downloads as FLV instantly. All processing runs in your browser.
What codec is used for FLV?
The default codec for FLV is Sorenson Spark / MP3. You can change the video and audio codec in Advanced mode.
How do you store my files?
We do not store any processed videos. All conversion happens entirely in your browser using FFmpeg WASM.