Video conversion
Convert MKV to FLV
Updated Jul 2026
MKV is a flexible container that can hold video, audio, subtitles, and chapters at full quality. FLV is an older web video format that some legacy players and streaming tools still expect. To convert, open the file in a converter and export it as FLV, and doing that on your own computer means the video never has to leave your machine.
- Extension
- .mkv
- Type
- Video
- Typically
- High-quality video containers
- Extension
- .flv
- Type
- Video
- Typically
- Legacy web video
- Compression
- Lossy
Convert MKV to FLV on your own computer. Nothing uploads.
How to convert MKV to FLV
- Open Morphjet and drag in the MKV file you want to convert, or a whole folder of them.
- Choose FLV as the output format.
- Convert. The FLV file is written next to your original, and nothing leaves your machine.
MKV vs FLV: what actually changes
| MKV | FLV | |
|---|---|---|
| File size | Larger, holds full video and audio quality | Smaller, mainly because quality and bitrate are reduced |
| Quality | High, matches whatever the original encode was | Lower, capped by the codecs and bitrates FLV supports |
| Opens everywhere | Not always, some phones and browsers can't play MKV directly | Rarely now, most modern browsers and devices dropped Flash-era support |
| Subtitles and multiple audio tracks | Yes, can hold several of each | No, limited to one video and one audio stream |
| Legacy streaming pipelines | Not typically used there | Yes, some older RTMP-based streaming tools still expect it |
| Chapters and metadata | Yes, rich metadata and chapter support | No, minimal metadata support |
When to convert, and when not to
Convert MKV to FLV when you're feeding a video into an older streaming pipeline, encoder, or platform that specifically expects the FLV container, usually something built around RTMP-based delivery.
Keep the MKV original if you just need a file to play or share normally, since FLV is a legacy format most modern players, phones, and websites no longer expect.
Why not just use an online converter?
Online converters ask you to upload your video to their server, wait, then download it back, which means a stranger's server holds a full copy of your video in the meantime. Converting MKV to FLV on your own computer skips that step entirely. The file changes format without ever leaving your machine.
Questions
Does converting MKV to FLV lose quality?
Yes, some. FLV supports fewer codecs and generally lower bitrates than MKV can hold, so the conversion usually involves real compression, not just repackaging.
Will subtitles and extra audio tracks carry over?
No. FLV can only hold one video stream and one audio stream, so if your MKV has embedded subtitles or multiple audio tracks, only one of each will make it into the FLV.
Why would anything still need FLV in 2026?
Mostly legacy reasons. Some older streaming servers, encoders, and RTMP-based broadcast tools were built around the FLV container and still expect it, even though the software that made FLV popular has long been discontinued.
Can I convert MKV to FLV without uploading the file anywhere?
Yes. A desktop app like Morphjet converts the file locally on your own computer, so the video never has to travel over the internet.
Morphjet converts MKV, FLV, and 1,800+ other formats, all on your machine. Launching this July.