.png)
简体中文 
OBS Studio is one of the most capable free recording tools available, but it does not output MP4 by default. If you keep ending up with MKV files you cannot easily share or upload, this guide has you covered. The three methods below walk you through switching directly to MP4, manually remuxing an existing MKV after recording, and enabling auto-remux so OBS handles the conversion for you every time.
How to Make OBS Record in MP4 (3 Methods That Actually Work)
Why OBS Doesn’t Record in MP4 by Default
OBS defaults to MKV because the format is crash-safe. If OBS or your PC shuts down unexpectedly mid-recording, a partial MKV file can still be recovered and played back. MP4 requires a final write step to close the file correctly, so an interrupted MP4 recording is completely unplayable, which is exactly why all three methods below exist.
Method 1: Change OBS Output Format Directly to MP4
This is the fastest route if you want MP4 files immediately and are comfortable with the crash-risk trade-off. The steps differ slightly depending on which Output Mode you are using.
Steps for Simple Output Mode
- Open OBS and click Settings in the bottom-right corner.
- Select the Output tab from the left sidebar.
- Confirm that the Output Mode dropdown at the top is set to Simple.
- Under the Recording section, open the Recording Format dropdown and select mp4.
- Click Apply, then OK.
Note: OBS will show a warning when you select MP4, alerting you that recordings may be unrecoverable if the application crashes. For short, stable desktop recordings the risk is low, but for long sessions or unattended captures, Methods 2 or 3 are the safer choice.
Steps for Advanced Output Mode
- Open OBS and click Settings.
- Select the Output tab.
- Switch the Output Mode at the top from Simple to Advanced.
- Click the Recording tab that appears within the Output settings.
- Find the Container Format (or Recording Format, depending on your OBS version) and select mp4.
- Click Apply, then OK.
Method 2: Record in MKV, Then Remux to MP4 (Recommended by OBS)
This is the method OBS officially recommends. You record in crash-safe MKV as normal, then convert the finished file to MP4 inside OBS with a few clicks. The process is a pure container swap, meaning no re-encoding occurs and quality is completely preserved.
- In Settings → Output → Recording, confirm the Recording Format is set to MKV (this is the OBS default).
- Record as normal and stop the recording when finished.
- In the OBS menu bar, click File and select Remux Recordings.
- In the Remux window, click the folder icon next to the OBS Recording field and browse to your MKV file.
- Click Remux and wait a few seconds. OBS creates an MP4 file in the same folder as the original MKV.
The original MKV is left in place so you can verify the MP4 looks correct before deleting it.
Method 3: Enable Auto-Remux to MP4 (Set-and-Forget)
Auto-remux combines the safety of MKV recording with the convenience of automatic MP4 output. OBS records in MKV behind the scenes, then converts the file to MP4 the moment you stop recording. After the one-time setup below, you never need to touch the remux menu again.
- Open OBS and click Settings.
- Select the Advanced tab in the left sidebar.
- Scroll down to the Recording section.
- Enable Automatically Remux to MP4 using the toggle or checkbox.
- Click Apply, then OK.
Every recording session will now produce an MP4 automatically. OBS holds the MKV temporarily during the active recording and removes it once the remux completes.
MP4 vs. MKV in OBS: Quick Comparison
Use this table to decide which method fits your workflow.
| Factor | MP4 (Direct) | MKV then Remux to MP4 |
|---|---|---|
| Crash safety | File corrupts if OBS crashes | MKV is recoverable |
| Output format | MP4 immediately | MP4 after remux step |
| Quality loss | None | None (container swap only) |
| Best for | Short, stable recordings | Long recordings or streaming sessions |
Frequently Asked Questions
Q: Will OBS MP4 recordings get corrupted if my PC crashes?
Yes. MP4 requires a finalization write at the very end of the recording process. If OBS or your PC shuts down before that step completes, the entire file becomes unplayable. MKV does not require this closing step, which is why Methods 2 and 3 are the recommended approach for longer or unattended recording sessions.
Q: Does remuxing MKV to MP4 in OBS reduce quality?
No. Remuxing is a container-format change only. The actual video and audio data are not re-encoded or altered in any way. The resulting MP4 will be identical in quality to the source MKV, and file size will be the same or marginally smaller depending on container overhead.
Q: Where does OBS save the remuxed MP4 recording?
OBS saves it to the path set in Settings → Output → Recording Path. By default this is typically your Videos folder. You can update this field to point to any local directory, including an external drive or a dedicated project folder.
Q: Can I convert old OBS MKV recordings to MP4?
Yes, and you do not need to have just finished recording to do it. Open File → Remux Recordings at any time, click the browse icon to select any existing MKV file on your drive, and click Remux. OBS will create an MP4 copy in the same folder, leaving the original MKV untouched.
Conclusion
For most users, Method 3 (Auto-Remux) is the best default setup: one-time configuration, no extra steps after each recording, and full crash protection throughout. Once that is in place, a natural next step is reviewing your OBS recording quality settings or dialing in the right bitrate for MP4 output to get the best possible file for editing or uploading.
