Compress Video for MKV video (100 MB Limit)

Compress large MKV recordings and convert them to a standard H.264 MP4 in one cloud job. The 45 MB preset suits common sharing workflows.

OBS uses MKV because it is safer if recording is interrupted, but many editors, browsers and platforms do not accept the container or its multiple audio tracks.

MKV video file size limits, and what they really mean

These delivery targets pair a compatible MP4 output with enough headroom for common web and Discord upload limits.

Plan / upload methodMaximum file size
Web, CMS or LMS MP4 upload100 MB

A broadly compatible MP4 below a common 100 MB form cap.

Discord Nitro Basic50 MB

45 MB leaves headroom below 50 MB.

Discord Free20 MB

Use about 19 MB for the free upload tier.

Limits verified 2026-10-28. Sources: OBS Project — Recording formats and remuxing · Discord — File Attachments FAQ

What 45 MB actually buys you

Every other page tells you the limit and stops there. The limit is the easy half. Here is the half that decides whether your video is watchable: at a 45 MB target, this is exactly how much bitrate is left for each duration, and the largest resolution that bitrate can carry without falling apart.

Video lengthBitrate left for videoResolution it carriesVerdict
1 min6,038 kbps1080pLooks fine
5 min1,105 kbps480pLooks fine
10 min489 kbps360pVisibly rough
30 min78 kbps—Visibly rough

Method: the bitrate column is arithmetic — 45 MB spread across the duration, minus 128 kbps for stereo audio and 2% for container overhead. It is a hard ceiling, not an estimate. The resolution and verdict columns are a recommendation, derived from published H.264 bitrate ladders and pulled down about a third, because re-encoding footage that has already been compressed once survives lower bitrates than encoding a clean master does. Deliberately conservative — we would rather under-promise than tell you a video will look fine when it will not.

45 MB across lengths and resolutions

The left column is what you have to spend at each length; the cells are what each resolution needs. Green means you clear it comfortably, amber means it is watchable but soft, and grey means pick a smaller frame. Reading down a column shows how long a clip can get before that resolution stops being worthwhile on MKV video.

you haveneeded for comfortable quality1080p720p480p360p1 min6,0381 min at 1080p: 6038 kbps available; 4000 kbps for a comfortable result, 2000 kbps to stay watchable4,0001 min at 720p: 6038 kbps available; 2200 kbps for a comfortable result, 1100 kbps to stay watchable2,2001 min at 480p: 6038 kbps available; 1000 kbps for a comfortable result, 500 kbps to stay watchable1,0001 min at 360p: 6038 kbps available; 600 kbps for a comfortable result, 300 kbps to stay watchable6005 min1,1055 min at 1080p: 1105 kbps available; 4000 kbps for a comfortable result, 2000 kbps to stay watchable4,0005 min at 720p: 1105 kbps available; 2200 kbps for a comfortable result, 1100 kbps to stay watchable2,2005 min at 480p: 1105 kbps available; 1000 kbps for a comfortable result, 500 kbps to stay watchable1,0005 min at 360p: 1105 kbps available; 600 kbps for a comfortable result, 300 kbps to stay watchable60010 min48910 min at 1080p: 489 kbps available; 4000 kbps for a comfortable result, 2000 kbps to stay watchable4,00010 min at 720p: 489 kbps available; 2200 kbps for a comfortable result, 1100 kbps to stay watchable2,20010 min at 480p: 489 kbps available; 1000 kbps for a comfortable result, 500 kbps to stay watchable1,00010 min at 360p: 489 kbps available; 600 kbps for a comfortable result, 300 kbps to stay watchable60030 min7830 min at 1080p: 78 kbps available; 4000 kbps for a comfortable result, 2000 kbps to stay watchable4,00030 min at 720p: 78 kbps available; 2200 kbps for a comfortable result, 1100 kbps to stay watchable2,20030 min at 480p: 78 kbps available; 1000 kbps for a comfortable result, 500 kbps to stay watchable1,00030 min at 360p: 78 kbps available; 600 kbps for a comfortable result, 300 kbps to stay watchable600

Source: Computed, not measured — no encoder was run to produce this figure · Method: 45 MB spread over the duration, minus 128 kbps audio and 2% container overhead. Thresholds come from published H.264 bitrate ladders, reduced by about a third for re-encoded source.

How to compress a video for an MKV video

  1. Drop your video in

    MP4, MOV, MKV, AVI, WebM and 33 formats in all. Nothing to install — your browser uploads over a one-time link and the file never touches a third party.

  2. The target is already 45 MB

    We pre-set it below the hard ceiling on purpose. A target-size encode usually lands within a couple of percent of the number you gave it, but we have measured footage that overshoots by up to a tenth — and landing over a hard limit means the upload fails. Change it if you want a different number.

  3. Download and upload

    Encoding runs on our servers, so you can close the tab. The result comes back with no watermark on any plan, in an MP4 that an MKV video will accept.

MKV video compression FAQs

Can I compress MKV online?

Yes. Upload the MKV, choose a target and export a compatible MP4.

Why does OBS recommend MKV?

MKV is resilient when recording stops unexpectedly. OBS can remux it without re-encoding, but compression is needed to reduce size.

Will all audio tracks be preserved?

Output compatibility may select or mix tracks. Check important game, microphone and chat audio in the downloaded file.

What codec should I choose?

Use H.264 in MP4 for broad playback support. H.265 can be smaller but is less universally accepted.

The reasoning behind these numbers

OTHER LIMITS
Same tool, a different upload ceiling