MKV to MP4 Converter
Copies the H.264 stream instead of re-encoding, so quality is identical.
Up to 50 MB per file. Sign up free to convert files up to 100 MB.
| File name | Size | Convert to |
|---|
Checking files and selected output formats.
What to expect when converting MKV to MP4
Measured on a 720p H.264 MKV: 20.22 MB in, 20.23 MB out (+0.0%), finished in 0.11s, roughly 138x faster than real time because the video is copied, not re-encoded.
Quality: If both files use H.264 video and AAC audio, the conversion is a container swap, video bytes are copied with no re-encoding, so quality is preserved exactly.
Best for: playing high-quality video on iOS / Apple TV, embedding in PowerPoint, uploading to platforms that reject MKV.
Avoid when: the MKV has multiple audio tracks or subtitle streams you want preserved, MKV holds them better than MP4.
Tip: MKV is a more flexible container, MP4 is more compatible. The conversion usually keeps the video stream identical.
MKV to MP4 - Archive-quality video in a format players accept
MKV is built to hold everything at once, several audio tracks, several subtitle tracks, release-quality video. MP4 is built to be played. The conversion comes up when a downloaded file needs to go onto an iPhone, which will not play MKV natively, or up to a platform that does not accept the container. Watch what gets dropped: secondary audio tracks and embedded subtitles do not survive unless the tool is explicitly told to keep them.
MKV to MP4: what changes and what doesn't
MKV (Matroska) and MP4 are both modern container formats. If the MKV contains H.264 video and AAC audio (common for web-sourced video), conversion is a fast remux, streams are repackaged without re-encoding, preserving exact quality in seconds. If the MKV uses H.265, VP9, or DTS audio, the video and/or audio may need re-encoding to fit MP4's supported codec set. MKV features that MP4 can't carry (multiple subtitle tracks, chapter markers, complex audio configurations) are dropped during conversion.
Convert when the target device or platform only supports MP4, iPhones, iPads, many smart TVs, and most social media platforms prefer or require MP4. If you're playing on a PC with VLC or a Plex server, MKV works fine as-is.
MKV vs MP4: Side-by-side
Technical comparison of the two formats, useful for deciding which to use, or for confirming what changes during conversion.
| Property | MKV | MP4 |
|---|---|---|
| Full name | Matroska Video | MPEG-4 Part 14 |
| Year introduced | 2002 | 2001 |
| Developer / standard body | Matroska Foundation | MPEG |
| MIME type | video/x-matroska | video/mp4 |
| File extension | .mkv | .mp4 / .m4v |
| Compression | Codec-flexible (H.264, H.265, AV1, VP9) | H.264 or H.265 codec |
| Color / data depth | Up to 12-bit | 8/10-bit |
| Max dimensions / size | Codec-dependent | Codec-dependent (up to 8K) |
| Transparency | No | No |
| Animation | No | No |
| Standard / specification | Matroska | ISO/IEC 14496-14 |
| Best for | High-quality video with multiple audio/subtitle tracks | Universal video compatibility, plays on every device |
Use MKV when
- You're archiving films with multiple audio tracks or subtitles
- You want commentary tracks, dubs, or original audio all together
- You're storing content for a home media server (Plex, Jellyfin)
- You want to keep source-quality codec choices without transcoding
Use MP4 when
- The video is going to a website, phone, or messaging app
- You want it to play on TVs, browsers, and casual devices
- You're uploading to a streaming platform
- Simplicity matters more than flexibility
Ship as MP4, archive as MKV. If your video needs to just work everywhere, MP4. If you're building a proper media library with subtitles and multiple audio tracks per film, MKV. Converting between them is usually a remux (container-only swap) that takes seconds, no quality loss.