Convert MKV to MP4 — Free Online Converter
Convert MKV files to MP4 instantly. Preserve subtitles, audio tracks & chapters. Free online converter with no quality loss.
Conversion settings — add a file to adjust
About MKV files
MKV (Matroska) is an open container that can hold many video, audio and subtitle tracks in one file. Screen recorders, video downloads and movie rips often come as MKV, usually with H.264 or H.265 video inside.
Many phones, TVs, game consoles and video editors will not open MKV, even though the video inside is fine. Changing the container to MP4 makes the same video play on those devices.
How we convert MKV to MP4
- Fast path
- When you change no option, we move the video and audio tracks from the MKV into an MP4 without re-encoding them. Subtitle tracks come along where MP4 can hold them.
- Fallback
- If a track cannot live inside MP4, we delete the partial output and re-encode to H.264 at CRF 23 with AAC sound at 192 kbps.
- Tracks
- All video and audio tracks are mapped, so a second language track is not lost on the fast path.
- Measured
- A 30-second 1080p MKV of 22.0 MB became a 22.1 MB MP4 in about 4.5 seconds of processing.
Common problems and fixes
The MP4 has no sound on my TV.
Some MKV files carry a surround or lossless audio codec that your TV cannot decode. Set an audio bitrate or pick a quality preset so the sound is re-encoded to AAC.
The picture plays on my PC but not on an older phone.
The MKV may hold H.265 video, which the fast path keeps. Pick the High, Medium or Low preset to force an H.264 re-encode.
About MKV to MP4 Conversion
MKV (Matroska) is beloved by video enthusiasts for its ability to store multiple audio tracks, subtitles, and chapters in a single file. However, this flexibility comes at the cost of compatibility—many devices and platforms struggle with MKV playback. Converting MKV to MP4 preserves your content while unlocking universal compatibility.
Our MKV to MP4 converter handles multi-track files: on the fast path it copies every video and audio track, and subtitle tracks where MP4 can hold them. When your MKV already uses H.264 video, we perform a lossless remux that simply repackages the content in MP4 format—no quality loss whatsoever.
Why Convert MKV to MP4?
MKV files are common in video downloads, Blu-ray rips, and anime releases, but they frequently won't play on smart TVs, game consoles, or iOS devices. The "file not supported" error is frustrating when you just want to watch your content. Converting to MP4 eliminates these compatibility headaches.
MP4 is the universal language of digital video. Every smartphone, tablet, computer, smart TV, and streaming device plays MP4 without issues. Social media platforms, cloud storage services, and video hosting sites all accept MP4 natively. Your converted videos will work everywhere.
The conversion also simplifies multi-track files. MKV's support for 20+ audio tracks is overkill for most viewers. Our converter lets you extract just the tracks you need, creating a cleaner, smaller file that's easier to manage.