FLV to MKV converter
Convert FLV to MKV free online. Move Flash video into a modern Matroska container for media library use. No signup, 500 MB limit, auto-deleted in 1 hour.
Drop a file to convert here
or click to browse
About Matroska Video Container
Common Use Cases
- Archiving Flash video in a modern container
- Adding FLV content to media libraries
- Preserving legacy Flash content for local playback
Flash Video (FLV) was the web video standard of the 2000s, but Flash Player is dead and FLV support is disappearing from modern software. Converting to MKV preserves your FLV content in a modern container that works in VLC, MPV, Plex, and every serious media player. If the FLV contains H.264 video, the conversion can often be a fast remux with no quality loss.
FLV is a dead format tied to the defunct Flash Player ecosystem. MKV is an actively maintained container supported by every modern media player, with features like chapters, multiple audio tracks, and soft subtitles that FLV never supported.
Why Convert FLV to MKV?
Escape the dead Flash ecosystem
Flash Player is discontinued and FLV support is being removed from software. MKV ensures your content remains playable for years to come.
Potentially lossless for H.264 FLV
Later FLV files often contain H.264 video. FFmpeg can remux H.264 FLV to MKV without re-encoding, preserving quality perfectly.
Rich metadata and features
MKV supports chapters, multiple audio tracks, subtitle tracks, and metadata that FLV cannot carry. Your video gains capabilities it never had.
Universal player support
VLC, MPV, Plex, Jellyfin, Kodi, and every major media player handles MKV natively. FLV playback is limited to VLC and a handful of legacy players.
When to use each
FLV limitations
- Tied to dead Flash Player ecosystem
- No subtitle track support
- No chapter markers
- Single audio track only
- Shrinking software support
MKV advantages
- Plays in every modern media player
- Full subtitle support (SRT, ASS, PGS)
- Chapter markers for navigation
- Multiple audio tracks per file
- Growing ecosystem and active development
Common use cases
- Archiving Flash video in a modern container
- Adding FLV content to media libraries
- Preserving legacy Flash content for local playback
How to use
- Upload your FLV file. Drag and drop your Flash video file onto the upload area, or click to browse. Uploads are limited to 500 MB per file.
- Start the conversion. Click Convert File and FFmpeg wraps the FLV streams into a Matroska container. H.264 streams are remuxed directly; older codecs are copied as-is or re-encoded as needed.
- Download your MKV file. Download the MKV and play it in VLC, Plex, or any modern media player. Files are automatically deleted within 1 hour.
Frequently asked questions
- Will this re-encode my FLV video?
- If your FLV contains H.264 video, it is typically remuxed without re-encoding. Older FLV codecs (VP6, Sorenson) are also handled, though they may require re-encoding depending on MKV codec support.
- Why not convert to MP4 instead?
- MP4 is great for device playback. MKV is better for media libraries because it supports chapters, multiple audio tracks, and more subtitle formats. Choose based on your use case.
- Will the audio carry over?
- Yes. FLV audio (MP3, AAC, or Speex) is carried over into the MKV container. AAC streams are typically copied without re-encoding.
- Is FLV to MKV conversion free?
- Yes. Anonymous visitors get a free daily cap, registered users get a higher limit, and Premium or Lifetime members get unlimited conversions.
- Is there a file size limit?
- Yes, 500 MB per upload.
- Can I play MKV on my TV?
- Most modern smart TVs and streaming devices (Roku, Apple TV, Chromecast, Fire TV) can play MKV files. Older TVs may need a media server like Plex to transcode on the fly.
- Is it worth converting old FLV files?
- Yes. FLV support is disappearing from modern software. Converting to MKV future-proofs your content and makes it accessible in media libraries and modern players.