FLV belongs to the Flash era of web video, and almost nothing new should use it. This free mp4 to flv converter exists for the remaining legacy case: an old web player, an archived site, or a system that still ingests Flash Video and cannot be updated. It re-encodes to FLV with H.264 video and MP3 audio. Everything runs in your browser, never uploaded, no signup. The honest limits: the video engine loads once, about 30MB, on first use; modern browsers do not play Flash or FLV, so this file is not for a new website; and FLV offers no quality or size advantage over MP4.
How to use this mp4 to flv converter
From a MP4 file to a FLV file, in three steps.
Choose a .mp4 file from your device. The file stays in your browser and is never uploaded.
The tool re-encodes the video and audio into the FLV combination, ready for the destination described on this page.
Save the converted file and check playback on the target player or editor before deleting the original.
Why FLV conversion is a legacy rescue, not a modern choice
Choosing FLV for this job is about the destination, not about a single best format.
A small number of archived players and legacy ingest pipelines still ask for FLV. Conversion keeps those systems working without rebuilding them.
The output pairs modern-ish H.264 video with MP3 audio inside FLV, giving old decoders their best chance at a clean play.
When an old embed or archive can only serve FLV, converting a current MP4 is faster than re-creating the original project.
Encoding happens on your own device, so the clip never leaves your browser on its way to a legacy archive.
MP4 to FLV Converter FAQs
Short, direct answers to the questions readers ask most.
No. Browsers removed Flash years ago, so FLV is not a web publishing format any more. Use MP4 or WebM for any new web page.
Only for legacy systems: old players, archived sites, or ingest tools that cannot be updated. If no such system is involved, stay with MP4.
Some loss is possible, because the video is re-encoded. From a high quality MP4 the change is usually small, but FLV adds no quality back.
Not reliably. Do not count on subtitle tracks surviving into FLV.
Yes. It runs entirely in your browser, with no account, no signup, and nothing uploaded.
Related Tools
More free converters that work the same way – right in your browser.
Make a legacy AVI version of an MP4 for old Windows players.
MP4 to WMV ConverterMake a Windows Media version of an MP4 for PowerPoint and Windows playback.
MP4 to WebM ConverterMake a modern web-friendly WebM version for HTML5 video instead.
Video to MP3 ConverterPull just the audio out of a video as an MP3, right in your browser.
Try the related tools above, or go back to the Convertion homepage for more free converters.
