How to Make OBS Record in MP4 (Instead of MKV)

If you use OBS for recording tutorials, code demos, or gameplay on Mac, you have likely encountered the .mkv problem. By default, OBS saves recordings as MKV files. While MKV is a robust container format, most macOS editors (like Final Cut Pro, iMovie, or QuickTime) and browser-based uploaders won't accept it.

You try to drag the file into your editor, and nothing happens. You are forced to convert the file before you can use it.

Here is how to configure OBS to output standard MP4 files automatically.

The Warning: Why OBS Defaults to MKV

Before changing this setting, you must understand why OBS does this.

If your Mac crashes, runs out of battery, or OBS freezes while recording to an MP4 file, the entire video file is corrupted and lost. MP4 files require a complete header at the end of the file to be readable.

MKV files do not have this limitation. If the recording stops abruptly, the file is saved up to the exact millisecond of the crash.

How to Record Directly to MP4 in OBS

If you are confident in your system stability and want to save directly to MP4:

1. Open OBS.
2. Go to Settings > Output.
3. In the Recording section, look for Recording Format.
4. Change the dropdown from mkv to mp4 (or mov).
5. Click Apply and OK.

Note: OBS will show a warning about file corruption in case of crashes. If you are recording short, low-stakes videos, this risk is negligible.

The Better Method: Auto-Remux to MP4

The safest way to use OBS is to record in MKV and have OBS automatically convert (remux) the file to MP4 the moment you stop recording. This takes less than a second and prevents file corruption.

1. Go to Settings > Advanced.
2. Scroll down to the Recording section.
3. Check the box for Automatically remux to mp4.
4. Click Apply and OK.

Now, when you click "Stop Recording," OBS will automatically output both an .mkv file and a converted .mp4 file in your destination folder.

Tired of OBS Complexity?

OBS is a powerful tool, but it is built for streamers. It requires configuring scenes, managing audio routing, and dealing with complex encoding profiles. If you just need to record your screen, show your webcam, and share a high-quality video, the overhead of OBS is a bottleneck.

ScreenKite offers the power of a professional recorder with the simplicity of a native utility. It records directly to MP4, manages system audio natively, and includes automatic camera tracking and cursor zooming without any configuration.