FLV Converter
FileFlip converts FLV files into 30 other formats entirely inside your browser, using WebCodecs and FFmpeg compiled to WebAssembly. The FLV file is never uploaded to a server: it is read off your disk, converted on your own machine, and saved back by the browser. There is no file-size limit and no account to create.
How do I convert an FLV file?#
- Drop your FLV file onto the converter at the top of this page, or click it to pick one from your computer.
- Choose the format you want out of it. FileFlip downloads the engine that conversion needs, once, and your browser caches it.
- Conversion starts the moment you pick the format, and the result is yours to download. The work happens in this tab, so nothing is uploaded and nothing is queued.
Is it safe to convert FLV files online?#
Yes, because nothing is uploaded. FileFlip converts FLV files inside the browser tab you already have open, using WebAssembly builds of the same engines a desktop converter would install. Your file is read from your own disk into the page's memory, and no request carrying it is ever made.
You do not have to take that on trust. Open your browser's network panel, run a conversion, and you will see the engine come down and your file go nowhere. There is no upload, no server-side copy, no retention window, and no account tied to what you converted.
How FileFlip works lists every engine, its version and its download size, and shows how to check for yourself that nothing leaves your machine.
What happens to a FLV file#
FileFlip converts FLV into 30 formats with WebCodecs and FFmpeg, all of it inside the browser tab. Each conversion below names the engine it uses, what it downloads, and exactly what that conversion keeps or drops.
| Category | Video Files |
|---|---|
| File extension | .flv |
| FileFlip support | Read and written |
| Conversions available | 30 |
| Engines | WebCodecs and FFmpeg |
| Downloaded to your browser | 30.8 MB on the first conversion, then cached |
What is an FLV file?#
An FLV file holds video and audio in tagged chunks meant to be streamed to Adobe's Flash Player, which is the only thing that ever played the format natively and has not shipped since the end of 2020.
There is no reason to create an FLV now; the only sensible use is holding on to one as the untouched original of something you have already converted.
Convert FLV to MP4 as soon as you find one, since the wrapper is the only thing standing between you and video that still plays perfectly well.
The FLV file format reference covers the specification, the programs that open one, and what each conversion keeps or drops.
FLV questions people ask#
Is FLV dead?
FLV is dead as a delivery format. Adobe stopped supporting Flash Player on 31 December 2020 and began blocking Flash content from running on 12 January 2021, and browsers had already removed the plugin before that. Nothing on the modern web plays FLV. The video inside an old file is usually still perfectly good, which is why converting rather than discarding is the right move.
How do I open an FLV file?
VLC opens FLV files directly on Windows, macOS and Linux, and it is the most reliable way to watch one without converting anything. Players built on FFmpeg, mpv among them, read the format too. What will not work is double-clicking the file and hoping the system handles it, because no operating system has shipped FLV support since Flash was retired.
What codec is inside an FLV file?
FLV is a container, and which codec it holds depends on when the file was made. Early files use Sorenson Spark, then VP6 became common, and H.264 arrived with Flash Player 9 Update 3 in December 2007. Audio is usually MP3, Nellymoser or AAC. This matters when you convert: knowing what is inside tells you whether the video can be rewrapped untouched or has to be encoded again.
Does converting FLV to MP4 lose quality?
It depends entirely on the codec inside the FLV. A later file holding H.264 can be remuxed into MP4, which lifts the same video stream into a new container and loses nothing at all. An older file holding Sorenson Spark or VP6 has to be re-encoded, because MP4 cannot carry those codecs, and re-encoding always gives up a little detail. Either way the picture cannot get better than the FLV was.
What was FLV used for?
FLV was how video reached the web through the 2000s. Sites embedded a Flash player and streamed FLV to it over RTMP or plain HTTP, which sidestepped the codec and plugin mess of the time by relying on Flash being installed everywhere. YouTube launched on Flash in 2005 and switched to HTML5 as its default player in January 2015, which is roughly the arc of the whole format.