What happens when you convert FLV to MKV
| Inside a typical FLV | H.264 or Sorenson Spark video with AAC or MP3 audio |
|---|---|
| Copy without re-encoding | Yes, almost always: MKV accepts any codec, so streams are copied in seconds |
| When re-encoded | H.264 video with AAC audio |
| Extra tracks | Your file's first video and audio track are kept |
| Opens in | VLC, mpv, Plex and most smart TVs; browsers, iPhones and editors often do not |
Sizes are typical values; your files will vary with content and settings.
FLV Flash Video
FLV was the Flash Player video format behind early YouTube. Flash is gone, so FLV files now need converting before modern devices will play them.
FLV converterMKV Matroska Video
MKV is an open container that can hold almost any codec plus multiple audio tracks and subtitles. It is popular for archived films and series.
MKV converterHow to use the FLV to MKV Converter
- 1
Choose a FLV file or drop it onto the page.
- 2
Review the video options. The defaults suit most files.
- 3
Click Convert and download your MKV when processing finishes.
Why convert FLV to MKV?
FLV files are leftovers from the Flash era: old video downloads, game captures and livestream archives. No modern browser or phone plays FLV. Choose MKV to repackage video without re-encoding, since it accepts any codec.
Frequently asked questions
Will the MKV lose quality?
Both formats are lossy, so converting re-encodes the data once more. Using a high quality setting keeps the generational loss very small. Avoid converting the same file back and forth repeatedly.
Does converting FLV to MKV re-encode the video?
Yes, almost always: MKV accepts any codec, so streams are copied in seconds. A typical FLV contains H.264 or Sorenson Spark video with AAC or MP3 audio. Otherwise the result is H.264 with AAC audio.
Questions about privacy, file-size limits or conversion speed are answered in the general FAQ.