OBS Studio ships with its own MP4 converter, and most people never find it because it sits under the File menu rather than in Settings. This walks through both official routes — the one you run by hand and the one you switch on once — and then tells you, honestly, the one thing OBS's documentation never actually states about either of them.
All you need is OBS Studio and at least one finished recording. Nothing extra gets installed.
Before you start
Know which container you are actually recording to. Open Settings → Output and look at Recording Format. OBS's Standard Recording Output Guide describes the setting and its recommendation in one breath: "Recording Format is the file format that your recording will be output in. MKV is recommended in case of unforeseen issues arising, since MKV will not corrupt the whole file if there is no graceful stoppage of recording."
That same screen has Recording Path — "where your recordings will go on your computer", in the guide's words. You will need that folder in a moment.
Do not trust a blog post about what your default is. OBS's Audio/Video Formats Guide calls MKV the default container ("MKV is the default container and recommended for most use cases, as it can be easily remuxed into a more compatible format"), while the same page labels "Hybrid MP4 (Windows/Linux default) / Hybrid MOV (macOS default)". Both statements sit on the official page, and OBS does not explain which one wins. So check what your own build shows in Settings → Output rather than assuming.
This matters because of a real possibility: if your build is already recording Hybrid MP4, you may have nothing to remux. Hybrid MP4 was introduced in OBS 30.2 and Hybrid MOV in OBS 32.0, and OBS describes them as aiming "to provide reliable and compatible output without the drawbacks of traditional or fragmented MP4/MOV". Open the recording in your editor first; if it imports cleanly, stop reading here. (Hybrid MP4, explained.)
Method 1: File → Remux Recordings
This is the manual route, for files already sitting on your disk. OBS's own wording, verbatim:
"If you record in a file format that is not mp4 and want to convert it to mp4 for easy use in the video editing software of your choice or to make it easier to upload to social media, OBS has that built in for you. If you click on File then select Remux Recordings and press the … button to select which video(es) you'd like to remux. After that hit the Remux button and OBS will convert your videos for you, once completed it'll provide a prompt saying so."
Broken into steps:
- Open the File menu in the OBS main window and choose Remux Recordings. This is not in Settings, which is why people miss it.
- Click the
…button to browse for the recording you want converted. Point it at your Recording Path folder. - Press Remux, then wait for the prompt. The guide says that "once completed it'll provide a prompt saying so" — that confirmation is your signal, not the appearance of a file in the folder.
Method 2: turn it on once in Settings → Advanced
If every recording ends up needing the same treatment, do not do this by hand. OBS, verbatim again:
"You can also select Automatically remux to mp4 if you know you'll always need your videos remuxed. If selected OBS will remux your video as soon as you stop recording"
The checkbox is labelled "Automatically remux to mp4" and lives in Settings → Advanced. The behaviour OBS documents is narrow and specific: it fires as soon as you stop recording. That is a statement about recordings you make from then on. For files already on disk, you are back to Method 1.
What OBS says remuxing does — and what it does not say
Here is the part that every other article on this keyword gets wrong by omission.
Search for "OBS remux" and you will be told, confidently and everywhere, that remuxing is lossless, that it does not re-encode, and that it finishes in seconds. None of that appears in OBS's own knowledge base. The word the documentation uses — in the passage quoted above, which is the entire official treatment of the feature — is "convert". It never says whether the video is re-encoded. It never says the quality is unchanged. It never says how long it takes.
The same silence covers three more things people assume:
- Whether your original MKV survives. Not documented.
- What happens when auto-remux fails. Not documented.
- What happens to a recording whose codec MP4 cannot hold. Not documented — and this one has teeth, see below.
None of that means the popular claims are wrong. It means they are not sourced, and you should not plan an archive or a client deliverable around an unsourced claim. The practical move: run one remux, keep the original, and compare the two files yourself before you trust the process with anything irreplaceable. If you want the underlying mechanism of copying streams between containers explained from primary documentation, we cover it in extracting audio without re-encoding, where the claims are attributed to FFmpeg's own docs rather than to OBS.
If you are not at your OBS machine
Container conversion is not something you need OBS for. This runs in your browser tab — the file is read from disk, processed locally, and handed back; it is never uploaded anywhere:
Try it right here
Runs in your browser. Your file is not uploaded anywhere.
Be clear about what this is, though: MP4 to MKV re-encodes to H.264 with AAC audio rather than copying the existing streams across, so it is a conversion, not a remux in the strict sense. Reach for it when you want an MP4 wrapped back into the more resilient MKV container for archiving, or when a tool in your chain accepts only one container. For every other pairing, see all Clapr tools.
Common mistakes
- Hunting through Settings for the manual remux. It is under File, not Settings. Only the automatic option lives in Settings, and specifically under the Advanced tab — not under Output, where the recording format is.
- Expecting MP4 to accept everything MKV accepted. OBS's container/codec table marks MP4 as supporting H.264, HEVC and AV1 but not ProRes, while MKV supports all four. If you recorded ProRes — which OBS documents as a VideoToolbox recording option on Apple Silicon Macs — MP4 is not a destination those tables allow. What the remux tool does in that case is not written down anywhere in the knowledge base; check the official documentation first.
- Recording straight to MP4 to skip this article. OBS argues against it plainly: MP4/MOV "require "finalisation" of a file to be playable, if the writing is interrupted for any reason the file may not be recoverable. It is therefore not recommended to record to MP4/MOV directly." Record resilient, convert afterwards — that is the whole reason the remux feature exists. The full trade-off is in MKV or MP4 for OBS recordings.
- Forgetting that multi-track recordings are a special case. OBS's advanced recording guide says "Not all recording formats (container) allow for multi track audio. We suggest using mkv (you can remux later to mp4)" and, for the Advanced Output Mode it describes, that this "will allow you to record multiple audio track (up to 6)". What survives the trip to MP4 is not documented per-track, so check your output in an editor that can show every track before you delete the MKV.
FAQ
Where is Remux Recordings in OBS?
In the File menu of the main OBS window — File → Remux Recordings. Then use the … button to pick your recording and press Remux. It is not in Settings.
Does remuxing in OBS lose quality? OBS's knowledge base does not say. Its only description of the feature says OBS "will convert your videos for you" — it makes no claim either way about re-encoding or quality. Treat the widespread "it's lossless" claim as unsourced, keep your original file, and check the result yourself.
Does OBS delete the original MKV after remuxing? Not stated in the official documentation. Assume nothing: after your first remux, look in your Recording Path folder and see what is there before you build a workflow around it.
How do I make OBS remux every recording automatically?
Tick "Automatically remux to mp4" in Settings → Advanced. OBS says it will then remux "as soon as you stop recording". Files already on disk are not covered by that description — use File → Remux Recordings for those.
My remuxed file plays with no sound. Is remuxing the cause? Not necessarily — the far more common cause is track assignment at record time, which happens in two separate places in OBS. That one has its own walkthrough: OBS recording has no audio.
All OBS behaviour above is quoted from OBS Studio's own knowledge base — the Standard Recording Output Guide, Audio/Video Formats Guide, Hybrid MP4 & Hybrid MOV Formats, and Advanced Recording Guide — checked 16 September 2026. Where the knowledge base is silent, this article says so instead of guessing; start at OBS Help to verify. More step-by-step walkthroughs live in our how-to guides.
