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Remux an OBS recording to MP4
- Stop the recording. Keep the original file until you have checked the MP4.
- In OBS, select File > Remux Recordings.
- In the file picker, choose one or more recordings to convert.
- Click Remux and wait for OBS’s completion prompt.
- Open the resulting MP4 in the editor or player you intend to use. Check the picture, sound, duration, and any audio tracks you need.
OBS documents this manual workflow in its Standard Recording Output Guide. Menu wording can vary by OBS version.
What remuxing does—and what it does not do
A video file has a container, such as MKV or MP4, that holds encoded video, audio, and sometimes other streams. Remuxing copies selected encoded streams into a different container without decoding and encoding them again. FFmpeg describes stream copy as useful for changing the container format or modifying container-level metadata in its documentation.
- It preserves the selected encoded streams: there is no new lossy encoding pass, so remuxing itself does not reduce their quality.
- It does not convert or repair streams: the video and audio codecs remain the same. Resolution, frame rate, and bitrate are not changed by stream copy.
- It is not guaranteed to work for every file or destination: MP4 and the target application must support the stream types involved. A remux can fail, or the output can be unusable in a particular editor, if a codec or stream is unsupported.
If the destination rejects the codec, remuxing will not fix that incompatibility. You may need a different container supported by the application or a separate transcoding step, which decodes and re-encodes the affected stream.
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Why OBS recommends recording to MKV first
OBS recommends MKV because an interrupted recording is less likely to lose the whole file. Traditional MP4 and MOV recordings require finalization; if writing stops unexpectedly before finalization, the file may be unrecoverable. OBS explains this trade-off in its recording guide and audio/video formats guide.
A practical workflow is therefore to record in MKV, stop the recording normally, and remux the completed file to MP4 for an editor or playback application that needs MP4. Keep the MKV until you have confirmed the output works where you need it.
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Automatically remux future OBS recordings
To have OBS create an MP4 after each recording ends, open Settings > Advanced and enable Automatically remux to mp4. OBS says it remuxes the video as soon as recording stops. Check the setting in your installed version, since labels and locations may change. Automatic remux does not change the recording’s codec choices or guarantee compatibility with every editor.
Use FFmpeg for stream copy or batch workflows
FFmpeg is an alternative when you want command-line control, scripting, or explicit stream selection. First inspect the input streams and decide which video, audio, subtitle, or other streams you actually need. FFmpeg’s documented example is:
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ffmpeg -i INPUT.mkv -map 0:1 -c copy OUTPUT.mp4
Here, -map 0:1 selects the second stream in the first input, and -c copy copies it without decoding or encoding. This example maps only one stream; it is not a command to preserve every video and audio track.
To attempt to copy all input streams, a commonly used form is:
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ffmpeg -i input.mkv -map 0 -c copy output.mp4
Check the source stream list and FFmpeg’s output warnings. The command can fail if MP4 cannot carry a selected stream or if the container needs information the input does not provide. Do not treat stream copy as a compatibility conversion. The FFmpeg documentation covers mapping and stream copy behavior.
Choose the workflow that fits the job
| Workflow | Best suited to | Control and caveat |
|---|---|---|
| OBS manual remux | A one-off recording or a small number of existing files | Simple file-picker workflow; codec and container compatibility still apply. |
| OBS automatic remux | Future recordings you want as MP4 after stopping | Convenient, but the original recording settings still determine the streams. |
| FFmpeg stream copy | Batching, scripts, or explicit stream selection | More control, but requires careful mapping and compatibility checks. |
Consider Hybrid MP4 when choosing a recording format
OBS 30.2 introduced Hybrid MP4, which writes in a fragmented form and finalizes using a soft-remux process. OBS describes it as aiming to combine recovery resilience with compatibility in software that recognizes regular MP4. Its format guide lists H.264, HEVC, and AV1 video for Hybrid MP4, while audio support and third-party application compatibility still matter. It is a possible recording option if your installed OBS version offers it—not a method for remuxing an existing file. See OBS’s Hybrid MP4 & Hybrid MOV Formats guide before changing formats.
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Troubleshooting remux problems
OBS reports an error or does not produce an MP4
- Confirm the recording has finished and that the original file can be opened.
- Check whether the source contains streams that MP4 cannot carry; identify the codecs and tracks before trying a different container or transcoding.
- If using FFmpeg, review the stream mapping and warnings. A mapping that selects only one stream will not preserve other tracks.
The MP4 exists, but the editor has no sound or rejects the file
- Test the output in the intended application and verify which audio tracks were included.
- Check the source’s video and audio codecs against the destination application’s supported formats. Changing the container alone leaves the codecs unchanged.
- If the editor cannot decode a stream, choose a compatible container or transcode that stream; do not expect another stream-copy attempt to change its codec.
The original recording is damaged after an interruption
MP4/MOV files that were not finalized may be unrecoverable. For future recordings, use the MKV-first workflow or, if available and compatible with your setup, consider Hybrid MP4. Neither option can guarantee recovery in every failure.
Or let it run in the cloud
Remuxing is for completed recordings; it does not keep a live channel running. If your goal is a 24/7 YouTube stream made from uploaded videos, StreamNeo is a separate cloud service: upload a recording or build a playlist, add your YouTube stream key, and go live. Nothing has to stay on at home. It streams the uploaded file as made, up to 4K 60fps, at one price per slot, and automatically recovers if YouTube drops the stream. The first day is free with no card. Monthly pricing is $9.99 per month. StreamNeo is for YouTube and uploaded videos, not camera-based live capture. Learn more at StreamNeo, or start the free first day.
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