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Free tools › Audio and video

MP4 to MKV

The open container Plex, Kodi and VLC favour, holding the same picture and sound.

This one runs on your credits. The open container Plex, Kodi and VLC favour, holding the same picture and sound.

Sign in and get 500 free credits every month — enough for many files — then drop the file in the workbench and run mp4 to mkv there.

Pick a file below to see exactly what it would cost.

Sign in and run it — free credits included

More free conversions, where you upload. The Fylane extension does the same work inside any upload form, on its own free share every day.About the extension

How to convert MP4 to MKV

  1. Drop the video.
  2. Nothing to choose.
  3. Press Convert and download the MKV.

What happens to your file

The video is re-encoded as H.264 with AAC sound and written as a Matroska file. MKV can carry many subtitle and audio tracks and any codec; this page writes the one video and one audio track of the file you gave it.

Questions

Will my phone play an MKV?

Android mostly yes, iPhone only through VLC or a similar app. For sending to people, MP4 is the safer choice; MKV is for the library at home.

Do this in code

curl -X POST https://api.fylane.dev/v1/jobs \
  -H "Authorization: Bearer $FYLANE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "file_id": "<file id>",
    "operation": "video.convert",
    "options": {
      "container": "mkv"
    }
  }'

The same operation, video.convert — Anything playable becomes H.264+AAC in a faststart MP4 — or, by `container`, MOV, MKV, VP9+Opus WebM, or Xvid+MP3 AVI for old players. Plus the small edits: mute, rotate, flip, speed (the sound keeps its pitch), reverse (60 s at most), loop. Upload first with the quickstart; every option is on the operations page. 500 free credits a month, then $5 per thousand.