How to convert MKV to MP4 and keep the audio

Changing a filename from .mkv to .mp4 leaves the recording inside untouched. This converter reads the source and creates a new MP4 with H.264 video and AAC audio when the source contains one supported audio track.

Step by step

1. Check the recording

   Choose one MKV up to 50 MB, with up to 1080p input and 60 frames per second. There is no fixed clip-length limit. A lightweight recording over a minute long can qualify, while a shorter high-resolution recording can exceed the file-size limit.

2. Choose MP4 and convert

   Open the MKV to MP4 converter and choose your file. MP4 is already selected. Choose Convert to MP4 and keep the tab open while the browser processes the video and checks the result.

3. Check sound and duration

   In Ready to download, compare the reported duration with the original and look for “with audio.” Download the MP4 and play the beginning and the last few seconds. For a speech recording, check that voices and lip movement line up.

What if the MKV has two languages or subtitles?

The tool accepts one video track and at most one audio track. If the recording contains multiple audio tracks or subtitle tracks, export a copy from your video editor with just the language you need and without subtitle tracks. A silent source produces a silent MP4. For an output over the 64 MB limit, split the recording or export a smaller source before retrying.