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ShrinkVid

Compress MKV Files

Drop an MKV below to compress it into a smaller MP4 or WebM. It is a quick way to shrink OBS recordings, which are often saved as large MKV files — everything happens on your device.

Processed on your device — files are never uploaded.

How to compress MKV files

  1. Drop your .mkv file.
  2. Choose a quality or target size.
  3. Pick MP4 (most compatible) or WebM.
  4. Compress and download.

MKV recordings from OBS

OBS recommends MKV because it survives crashes. Recordings are usually high bitrate, so a 10-minute 1080p60 capture can top 2 GB. Medium quality at 1080p with “Limit to 30 fps” turned on typically cuts that by 75% or more.

What happens to subtitles and extra audio tracks?

To keep the output simple and widely playable, ShrinkVid keeps the main video and main audio track. Extra audio tracks, subtitles and chapters are not copied.

Private by design

ShrinkVid never uploads your files. The page loads once, then all decoding and encoding happens on your device using the browser’s built-in WebCodecs API (hardware-accelerated video) and WebAssembly image codecs. That makes it safe for personal, confidential or work files — and there is no queue, no file size cap and no watermark. Read how it works.

Frequently asked questions

Are my files uploaded to a server?

No. ShrinkVid runs entirely in your browser. Files are read and encoded on your own device with WebCodecs and WebAssembly, so nothing is uploaded, stored or seen by anyone else. You can even disconnect from the internet after the page loads and it keeps working.

Can my browser read MKV files?

Yes — ShrinkVid includes its own MKV demuxer, so any browser with WebCodecs can read MKV files, as long as it can decode the video codec inside (H.264 and VP9 work everywhere; HEVC depends on your device).

Is it really free? Is there a watermark or file size limit?

It is completely free with no watermark, no sign-up and no server-side file size limit. Because processing happens on your device, the only practical limits are your device’s memory and speed.

Last updated · by the ShrinkVid team