MKV to MP4 Converter
Drop an MKV, get an MP4 that plays anywhere. Runs in your browser — no upload, no signup.
Drop your MKV file here
Converts to .mp4 — stays on your device
Why convert MKV to MP4?
- Making a Matroska movie rip playable on an iPhone, iPad, or Apple TV where MKV isn't supported natively.
- Converting downloaded MKV lectures or training videos to MP4 so they embed in PowerPoint, Keynote, or Google Slides.
- Preparing MKV anime or concert rips for AirPlay, Chromecast, or a smart TV that rejects the Matroska container.
- Importing MKV files into Premiere Pro, Final Cut Pro, or iMovie — all of which prefer MP4 for smooth timeline playback.
- Re-packaging multi-subtitle MKV files into MP4 for a Plex or Jellyfin library optimized for mobile clients.
- Uploading MKV screen recordings from OBS to YouTube or Vimeo — both accept MP4 far more reliably.
How our converter works
Your MKV is decoded by a WebAssembly build of ffmpeg running inside your browser, then re-encoded as MP4 with H.264 video and AAC audio — the combination every device on earth can play. MKV's multi-track flexibility (multiple audio streams, subtitles, chapters) gets flattened to MP4's more constrained structure; the primary video and first audio track carry through. Conversion speed is 1–3× the video's length, and nothing is uploaded — which matters if the MKV is a rip, a private recording, or unreleased footage.
MKV vs MP4 — what's the difference?
| Feature | MKV | MP4 |
|---|---|---|
| Origin | Matroska — open-source container, 2002 | MPEG-4 Part 14 — ISO standard, 2001 |
| Multi-track | Unlimited video/audio/subtitle tracks | Limited but widely compatible |
| Playback devices | Desktop players (VLC, mpv, Kodi) | Everything — phones, browsers, smart TVs |
| Streaming | Not supported by HTML5 video | Native HTML5 playback |
| Best for | Archival, multi-language rips, Plex libraries | Sharing, uploading, universal playback |
Frequently asked questions
Why won't my MKV play on iPhone or QuickTime?
Apple's ecosystem has never supported MKV natively — it's a Matroska container, not part of the MPEG-4 family. Converting to MP4 swaps the container (and re-encodes audio and video if needed) so iOS, macOS, and tvOS all accept the file.
Will I lose the extra audio tracks or subtitles?
Yes — MP4 carries the primary video track and the first audio track through. Embedded subtitles are not converted. If you need to preserve them, a desktop tool like HandBrake with its 'passthru' options is a better fit.
Does the video quality degrade?
Slightly. MKV and MP4 both usually contain H.264 or H.265 video, but since we re-encode, there's one lossy pass. At default settings (CRF 23, preset ultrafast) the visual difference is imperceptible.
How long does conversion take?
Roughly 1–3× the video's length on a modern laptop. A 30-minute MKV takes 30–90 minutes. For hour-long files, a desktop ffmpeg or HandBrake install will be faster.
Is there a file size limit?
Around 500 MB before browser memory starts failing. Large anime rips or multi-hour concert captures should use desktop tools.
Are my files uploaded?
No. Everything happens in your browser via WebAssembly. The file never touches a server.
About the MKV format
MKV (Matroska Video) is an open-source, extremely flexible container standardized in 2002. Its design goal was to hold anything: unlimited video tracks, unlimited audio tracks in any language, subtitle streams, chapter markers, custom metadata. That flexibility made it the default output of nearly every desktop ripper (MakeMKV, HandBrake, OBS), but also its weakness — Apple and most browsers never adopted it, so MKV effectively lives on desktop only. MP4 is the opposite: a disciplined, streaming-friendly container with a narrower feature set that works everywhere. Converting MKV to MP4 trades flexibility for compatibility, which is the right trade for almost all playback scenarios outside of a home media server.