How to Compress OBS Recordings: MKV, MP4, and File Size
6 tháng 11, 2026
Decide whether your OBS recording needs remuxing or compression, then create a smaller sharing copy while keeping the original.
If you need a smaller OBS recording, compress a copy of the video. If you only need to change MKV to MP4 for compatibility, try remuxing first. Remuxing changes the container without intentionally re-encoding the video, so it usually does not make a large recording substantially smaller.
Start with the OBS recording compressor when file size is the problem. Keep your original recording until you have watched and downloaded the sharing copy.
Remuxing and compression solve different problems
| Your problem | First action | What to expect |
|---|---|---|
| An editor will not accept the MKV file | Try OBS's remux function | An MP4 container with the existing encoded streams, when compatible |
| The recording is too large to send | Compress a copy | A new encode with a quality and file-size tradeoff |
| Only a short section is useful | Trim in your editor before compressing | Less duration to store and transfer |
| The recipient cannot play the codec | Export a compatible version | A container change alone may not be enough |
The container is the wrapper around the video and audio streams. Changing a filename from .mkv to .mp4 does not change that wrapper or convert the streams. See MDN's container format explanation for the distinction.
How to remux MKV to MP4 in OBS
OBS includes a remux utility under File → Remux Recordings. Select the source recording, check the destination, and run the remux. Open the result in the application where you need to use it.
The official OBS Standard Recording Output Guide describes this workflow and an automatic remux option. Menu wording can vary with the installed version.
Remuxing preserves the encoded media rather than choosing a new compression quality. If the existing codec is not accepted by your destination, use an appropriate re-encode instead. OBS's audio and video formats guide explains container and codec compatibility.
How to create a smaller sharing copy with TinyVideo
- Open the OBS recording compressor. Its cloud preset is selected for OBS recordings.
- Choose the recording you want to share. This is a cloud workflow: processing requires uploading the file and available cloud time.
- Review the selected workflow before starting. Use a short representative clip first if you are unsure whether the result will suit your content.
- Run the job and download the result while it remains available. Check the displayed retention deadline rather than treating cloud processing as permanent storage.
- Watch the downloaded copy before removing or archiving anything.
The size reduction depends on the source and the chosen workflow. A noisy game capture, a static slide presentation, and a webcam recording will not all compress by the same percentage. TinyVideo does not guarantee an exact output size for every recording.
For manual format, resolution, and quality choices, use custom cloud compression instead of assuming a fixed preset exposes every control.
Check the content that is hardest to compress
For gameplay, inspect rapid movement, grass, particles, and dark scenes. A still menu screen is not a useful quality test for the rest of a gaming session.
For tutorials, inspect small interface labels and code. Lowering resolution can make text harder to read even when the file becomes much smaller.
For meetings or interviews, check speech clarity and lip synchronization near the beginning and end. If the original has several audio tracks, verify that the sharing copy contains the track your audience needs; do not assume every processing workflow preserves all tracks.
Use the same playback size when comparing original and output. Keep a short note of the source size, result size, processing time, and any visible issue so you can choose the right workflow next time.
Why is my OBS recording still large?
Duration and average bitrate both contribute to file size. As a rough decimal estimate, a 30-minute recording at 20 megabits per second is about 4.5 GB for video alone: 20 × 1,800 ÷ 8 = 4,500 MB. Audio and container overhead add to that estimate.
For future recordings, review your OBS output settings and test a sample. Avoid changing several recording and compression settings at once; otherwise you will not know which change affected quality.
If your next step is sending the result as an attachment, check the destination's current limit and see compressing video for email. If you want a cover image for the recording, you can also extract a thumbnail from the video.