What is an FLV file?
FLV stands for Flash Video. It was created by Adobe (originally Macromedia) and first released in 2003. FLV powered YouTube and most web video until about 2010. Since browsers dropped Flash at the end of 2020, FLV files need converting or a desktop player.
F4V is the same format under another extension.
| Type | video |
|---|---|
| Compression | Lossy |
| Usually contains | Sorenson Spark, VP6 or H.264 video with MP3 or AAC audio |
| In a browser | does not play in browsers since Flash ended in 2020; plays in VLC |
| Common uses | old YouTube downloads and Flash-era video sites |
| MIME type | video/x-flv |
Which format should you convert FLV to?
- FLV to MP4 to play on any phone, computer or TV, or to upload to YouTube and social media.
- FLV to MP3 to keep only the soundtrack, for music or a podcast.
FLV is already lossy, so converting it to a lossless format makes the file bigger without improving it; pick a lossless target only if a program requires one.
How to open an FLV file
Whether an FLV file opens with a double click depends on the device. Here is what works on each, without buying software:
| Windows | Films and TV and Media Player open the common formats; VLC opens almost any video file, FLV included. |
|---|---|
| Mac | QuickTime Player opens formats Apple supports; VLC or IINA open the rest. |
| iPhone and iPad | The Files app plays formats Apple supports. For others, a player such as VLC for iOS, or converting the file here, is the easiest route. |
| Android | Most gallery and music apps play the common formats; VLC for Android plays almost everything. |
| Web browser | FLV does not play in browsers since Flash ended in 2020; plays in VLC. |
Want the technical details? See what a .flv file is, with its MIME type, file signature and a viewer.
FLV compared with other video formats
How FLV stacks up against the formats people most often convert it to or from:
| Format | Compression | Usually contains | Released | Best for |
|---|---|---|---|---|
| FLV | Lossy | Sorenson Spark, VP6 or H.264 video with MP3 or AAC audio | 2003 | old YouTube downloads and Flash-era video sites |
| MP4 | Lossy | H.264 or H.265 video with AAC audio | 2001 | phone videos, YouTube uploads, social media and streaming |
| MOV | Lossy | H.264, HEVC or ProRes video with AAC audio | 1991 | iPhone recordings, Final Cut Pro and screen recordings on Mac |
| MKV | Lossy | almost any codec, often H.264 or H.265 with several audio and subtitle tracks | 2002 | films and TV rips, OBS recordings and anime releases |
| WebM | Lossy | VP8, VP9 or AV1 video with Vorbis or Opus audio | 2010 | web video, screen recorders and browser-based recordings |
How to use the FLV converter
- Choose the format you want in the Convert to menu.
- Drop your FLV files on the box, or press Choose FLV files. Several files can go in at once.
- Adjust the settings if you need to; the defaults suit most people.
- Press Convert and save each file with its Download button. Nothing is uploaded at any point.
Tips for converting FLV files without losing quality
FLV is lossy, so some detail was already discarded when the file was made. Converting it cannot bring that back. Converting to a lossless format preserves what is left exactly but makes the file larger; converting to another lossy format adds a small extra loss, which is invisible at sensible settings.
- Keep the original recording. Every re-encode costs a little detail, so convert from the best copy you have, not from a file that was already converted.
- Know whether you need a new container or a new codec. MOV, MKV and MP4 can all hold H.264 video, and switching between them is fast and lossless; changing the codec means re-encoding, which is slower.
- For sharing, MP4 with H.264 at 1080p or 720p is the safe choice: every phone, browser and social network plays it.
- Phones record at very high bitrates. If a file is too big to send, lowering the resolution to 720p usually shrinks it far more than any quality setting.
Convert FLV files from the command line
Everything this page does can also be done in a terminal. The most common FLV conversion, to MP4, looks like this with ffmpeg:
ffmpeg -i input.flv -c:v libx264 -crf 23 -preset veryfast -c:a aac -b:a 128k -movflags +faststart output.mp4Change the output extension to pick another format. The converter above runs the same ffmpeg engine inside your browser, so you get the result without installing anything.
FLV converter FAQ
What is an FLV file?
FLV stands for Flash Video, a video format created by Adobe (originally Macromedia) in 2003. FLV powered YouTube and most web video until about 2010. Since browsers dropped Flash at the end of 2020, FLV files need converting or a desktop player.
How do I open an FLV file?
FLV does not play in browsers since Flash ended in 2020; plays in VLC. If the program you need will not open it, convert it to a more widely supported format above.
What is the most common FLV conversion?
FLV to MP4 is the conversion people search for most. If the video inside the FLV is already H.264, the tool first copies the streams straight into the MP4. That takes seconds and loses nothing.
Does converting FLV files here upload them?
No. Every conversion on this page runs inside your browser, so your FLV files never leave your device.
Is the FLV converter free?
Yes. There is no sign-up and no watermark, and no limit on how many FLV files you convert. The site is supported by advertising.
Can I convert FLV files on iPhone or Android?
Yes. Open this page in Safari on iPhone and iPad, or in Chrome on Android, choose your FLV files and download the results to your Downloads folder.
Can I convert several FLV files at once?
Yes. Drop as many as you like; they are converted one after another, each with its own download button.