Optimize high-quality video for mobile or TV playback. Every conversion runs locally on your Mac — your MKV files are never uploaded.
macOS 14 or later · Apple silicon · One-time purchase
MKV is a flexible high-quality video container popular for HD films. MP4 is the universal video format that plays on virtually every device. Optimize high-quality video for mobile or TV playback.
PrivateRemix handles the MKV-to-MP4 conversion in a couple of clicks, with the result saved right next to your original file.
Unlike free online converters, PrivateRemix has no server. Your MKV files stay on your Mac — no upload, no cloud, no account.
Drag a MKV file into PrivateRemix, or pick one from your Mac.
Select MP4 from the formats PrivateRemix offers for your file.
The new MP4 appears next to the original. Nothing leaves your Mac.
The change is minimal. Both formats are compressed, and you choose the size-versus-quality balance — Smaller file, Balanced, or Best quality — so everyday use shows no visible or audible drop.
PrivateRemix copies the video stream where possible, so there's typically no visible quality loss — you gain compatibility with phones, TVs and editors.
For sharing and playback, yes — MP4 is supported by nearly every phone, TV, browser and editor, which is why it's the safe default.
No. PrivateRemix runs entirely on your Mac using its own processor. Your MKV files never leave the device — there is no server to upload to, and it works fully offline.
Yes. Drop in a batch of MKV files and PrivateRemix converts them all locally, saving each new MP4 next to its original.
One-time purchase — no subscription. macOS 14 or later, Apple silicon.