Remux an OBS MKV recording to MP4 before importing it into an editor
Try OBS remuxing when an editor rejects the MKV container. Remuxing does not change the video codec, so an MP4 output can still be unsupported by the destination application.
Published · Updated · FaultNote editorial policy
Who this guide is for and what to prepare
- People who want to complete the task and inspect the saved result
What you need
- Stop recording and confirm that the original MKV exists
- Allow free space for both the source and the new output
1. Identify the compatibility issue
Play the original MKV first. If the recording is already missing content, changing the container does not guarantee recovery of that content.
Distinguish rejection of MKV from rejection of a codec such as AV1 or HEVC. The latter is not resolved merely by moving the same streams into MP4.
- Inspect original video and duration first
2. Select source and destination
Open File > Remux Recordings and select the source MKV in the OBS Recording field. Check the target MP4 path and choose a name that does not overwrite an unrelated existing file.
Selecting the input does not perform the operation. Start Remux, wait for completion, and then open the output folder.
- Verify source and destination names independently
3. Compare source and output
Open the MP4 and inspect duration, opening frames, motion in the middle, and the ending. For multitrack material, check that the required streams are available in the editor.
Completion confirms the container operation, not compatibility with every editor. Import the file into the intended timeline and test seeking and playback.
- Check the new file timestamp after completion
4. Decide whether to enable automatic remuxing
If every recording needs MP4, consider Automatically remux to mp4 under advanced recording settings. The guide describes remuxing after recording stops, so allow time for that output step.
Keeping MKV and MP4 uses space for both. For long sessions, establish available capacity and a retention rule before enabling automatic output.
- Seek to the middle and ending in the destination editor
5. Investigate remaining codec limits
If a player accepts the MP4 but the editor does not, check the editor support for the actual video and audio codecs. Repeatedly changing filename extensions does not convert those streams.
If required, transcode a copy into a supported format. This is a separate operation that can affect quality and takes encoding time; test a short section first.
- Allow storage for both original and new output
6. Retain the recording and hand off the MP4
Retain the MKV until the MP4 is verified. Record which file was used by the editor and avoid replacing it later with a different output under the same name.
Share the verified MP4. If reducing size is the goal, use a separate compression workflow with deliberate resolution and quality choices.
- Hand off the editing copy while retaining the original
7. Example: hand off a recording to an editor that rejects MKV
Suppose demo.mkv plays correctly but is absent from an editor import list. Check the supported container and codecs first. If the editor accepts MP4 with H.264 and the source is H.264, remuxing is a reasonable first attempt.
Set the target to demo-editor.mp4 and verify both fields before starting. Renaming the extension in a file manager does not rebuild the container structure and is not equivalent to remuxing.
Import the new MP4, place it on the timeline, and seek through the middle and ending. Opening the first frame alone does not establish that the entire recording imports reliably, so retain the original.
If the source is AV1 and the editor lacks AV1 support, MP4 can still be rejected. Retain the MKV and transcode to a supported codec as a separate operation. Make quality and processing-time choices deliberately.
Moving the imported file after editing begins can break project links. Establish locations for the original and editing copy and record them with the project. Retain the source for the period when new compatibility copies may be required.
8. Separate remux failure from playback incompatibility
If remuxing does not finish, confirm source presence and that recording has stopped. Check space, permissions, and name collisions. Try a separate target name instead of removing same-named files without establishing which is the original.
If the completed MP4 fails to play, compare with the MKV again. When only the source works, investigate destination support for the container and its codecs. An audio stream can be unsupported even if the video is acceptable.
Two files do not prove two separate recordings occurred; automatic remuxing can retain source and output. Check time, duration, and automatic-remux settings, then label which file is the original.
Copy the original before investigating possible damage. MKV can tolerate interrupted recording, but that is not a guarantee against media failure or footage never written. Inspect the complete output and do not describe missing content as a completed recording.
Limitations and requirements
- Keep the original material until the exported result works in the intended application.
Frequently asked questions
Does changing to MP4 lower quality?
Remuxing does not re-encode the video. It differs from transcoding, but destination codec and track support still require checking.
Is the original MKV automatically removed?
Treat remuxing as creation of a separate output and verify both files afterward. Decide original retention separately after inspection rather than deleting based only on a completion message.
Does MP4 work on every device?
Devices differ in codec, profile, and resolution support even with the same container. Test the actual destination device or application.
Sources and verification date
Sources checked: . These sources support the specifications, procedures or prices discussed here. Check each source for applicable conditions and current information.
Related practical guides
- Record one game in OBS with a specific Game Capture window
- Control OBS Window Capture matching when application titles change
- Crop and frame a source in OBS without stretching the image
- Save recent gameplay with the OBS Replay Buffer
- Record game audio only in OBS and test notification exclusion
- Diagnose OBS recording stutter with rendering and encoding statistics