Convert MKV to MP4 on Mac
MKV (Matroska) is a flexible, open-source container that can hold virtually any combination of video, audio, and subtitle tracks. However, Apple devices, most smart TVs, and many media players don't support MKV natively. Jollycat converts MKV to the universally supported MP4 format on your Mac, handling multiple audio tracks and embedded subtitles so your videos play everywhere.
MKV vs MP4
| Property | MKV | MP4 |
|---|---|---|
| Type | container | container |
| Compression | Any codec | H.264/H.265 + AAC |
| Container | Yes | Yes |
| Common Codecs | H.264, H.265, VP9, AV1, FLAC, AAC, DTS | H.264, H.265, AAC, MP3 |
| File Extension | .mkv | .mp4 |
| Key Advantage | Supports any codec | Universal device compatibility |
How to Convert MKV to MP4 on Mac
Add your MKV files
Drag .mkv files from Finder into Jollycat. The app detects all video, audio, and subtitle streams inside the MKV container and displays them.
Select MP4 and configure tracks
Choose MP4 as the output format. Select which audio tracks and subtitle streams to include. Choose H.264 for maximum compatibility or H.265 for smaller file size.
Convert
Click Convert. If your MKV already contains H.264 or H.265 video, Jollycat can remux the streams into MP4 without re-encoding — this is nearly instant and lossless.
When to Convert MKV to MP4
Playing on Apple TV, iPad, or iPhone
Apple's ecosystem doesn't natively play MKV files. Converting to MP4 lets you AirPlay, sync, or stream your videos to any Apple device without third-party players.
Uploading to streaming platforms
YouTube, Vimeo, and most video hosting services prefer MP4 with H.264. Converting from MKV ensures smooth uploads and faster processing on these platforms.
Smart TV and console playback
Most smart TVs, Roku, Chromecast, and game consoles support MP4 natively but have inconsistent MKV support. MP4 ensures reliable playback on all these devices.
MKV to MP4 Conversion Tips
MKV and MP4 are both container formats. If the video and audio codecs inside your MKV are compatible with MP4 (H.264/H.265 video, AAC audio), Jollycat can remux without re-encoding, producing identical quality in seconds.
MKV files often contain multiple audio tracks (different languages) and subtitle tracks. Jollycat lets you choose which tracks to include in the MP4 output, so you can keep only what you need.
If your MKV uses codecs like VP9 or Opus that aren't standard in MP4, Jollycat will re-encode to H.264/AAC automatically. This takes longer but ensures compatibility.
Frequently Asked Questions
Can I convert MKV to MP4 without losing quality?
Yes, if your MKV file contains H.264 or H.265 video with AAC audio. In that case, Jollycat remuxes the streams — essentially repackaging them into an MP4 container without any re-encoding. The output is bit-for-bit identical in quality.
Why won't my Mac play MKV files?
macOS does not include native MKV playback support. While VLC and other third-party players can handle MKV, Apple's built-in apps (QuickTime, TV app) cannot. Converting to MP4 makes your videos work with every Mac app and Apple device.
What happens to subtitles when converting MKV to MP4?
MKV files can contain embedded subtitle tracks in formats like SRT, ASS, or PGS. Jollycat lets you select which subtitle tracks to include and can embed them in the MP4 output or export them as separate subtitle files.
Ready to Convert MKV to MP4?
Jollycat handles MKV to MP4 conversion and 1,650+ other format conversions. All offline on your Mac.
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