---
title: "MKV to MP4 Converter for OBS Recordings, Free | ToolSugar"
description: "Remux MKV recordings to MP4 in your browser. OBS files with H.264 and AAC convert in seconds with no quality loss, and the file never leaves your device."
canonical: https://toolsugar.com/tools/mkv-to-mp4
image: https://toolsugar.com/og.png
---

# Convert MKV to MP4

Choose an MKV file and the tool copies its H.264 video and AAC audio straight into an MP4, which is called remuxing. It usually takes seconds, and the picture stays identical, even for a file up to 500 MB. Only MKVs that hold other codecs, such as HEVC or AV1, need a slower re-encode.

Runs on your device

## How it works

1. Choose an MKV file from your device.
2. Leave the method on Copy when possible.
3. Press Convert to MP4.
4. Read what was copied or re-encoded, then download the MP4.

## Key facts

- **H.264 MKV**: Remuxed into MP4 with an identical picture
- **File limit when copying**: 500 MB on a computer, 250 MB on a phone
- **File limit when re-encoding**: 120 MB on a computer, 60 MB on a phone
- **Dropped from the MP4**: Subtitles and any extra audio tracks
- **First run**: Some jobs download a 32 MB video engine once, then your browser reuses it
- **Your file**: Processed inside this tab and never uploaded

## Common uses

- Remux an OBS recording before editing it.
- Play an MKV on a TV or a phone that refuses the format.
- Upload a game clip to a site that expects MP4.
- Turn a local recording into a file that scrubs smoothly in a browser.

## Questions

### Is remuxing the same as converting?

For the result, yes. You get a real MP4. The difference is that remuxing moves the existing video and audio into the new container without changing them, so nothing is lost and it takes far less time.

### What happens to my extra OBS audio tracks?

Only the first audio track is kept. If you record game sound, microphone and music on separate tracks, the MP4 holds just the first. Export the others separately first if you need them.

### Will my MKV subtitles carry over?

No. Subtitle tracks are dropped because most MP4 players cannot use the formats MKV holds. To put subtitles on the video again, Auto Subtitles can create them from the speech.

### Is my video uploaded anywhere?

No. The video engine runs inside your browser tab and reads the file from your device. ToolSugar's servers never receive it, and closing the tab clears the working copy from memory.

[Read the MKV to MP4 guide](https://toolsugar.com/blog/how-to-convert-a-video-to-mp4)

## Related tools

- [Convert to MP4](https://toolsugar.com/tools/video-converter)
- [MOV to MP4](https://toolsugar.com/tools/mov-to-mp4)
- [Trim Video](https://toolsugar.com/tools/video-trimmer)
- [Auto Subtitles](https://toolsugar.com/tools/subtitle-generator)