Batch MKV to MP4 Converter
Convert MKV to MP4 online for free. 100% secure, fast, and private local file conversion directly in your browser. No software installation required.
Why convert MKV to MP4?
MKV (Matroska) is the container of choice for downloaded 1080p and 4K movies, TV episodes, and fan-subtitled releases because it can hold multiple video tracks, several audio languages, and soft subtitles in one file. The catch is support: most browsers, smart TVs, and built-in players only play MKV in some combinations of operating system and app, and many online platforms refuse it outright. Converting an MKV to MP4 keeps the picture and sound but wraps it in a container every device plays.
WasmConvert performs this remux-plus-re-encode locally, so the file never leaves your machine. When you convert MKV to MP4 here you can choose which audio track to keep when the source carries several, and the subtitle track is handled according to what MP4 can hold — normally embedded rather than burned into the picture. Because nothing is uploaded, there are no server queues or size caps, and large 4K rips convert on your own hardware with a quality setting you control.
Common use cases
- Playing downloaded 1080p or 4K MKV movie rips on a smart TV, console, or tablet with no MKV support
- Repairing a multi-language MKV so the right audio track plays everywhere instead of only in VLC or MPC
- Uploading an MKV episode or clip to a platform, course, or cloud drive that rejects Matroska files
How to convert MKV to MP4 (Step-by-step)
Select or drop your file
Click "Choose Files" or drag and drop your MKV file directly onto this page.
Set target format
Make sure the output format is set to MP4.
Local conversion
Click convert. Your file is processed entirely in your browser memory - no data is uploaded to our servers.
Save instantly
Once finished, your MP4 file is ready to download.
MKV is an open-source multimedia container that can hold an unlimited number of video, audio, and subtitle tracks. Convert MKV to MP4 for seamless browser playback.
MP4 is the most widely supported digital multimedia container format. It is universally compatible with all web browsers, smartphones, and media players.
Pro tips for MKV to MP4 conversion
- When the MKV carries several audio tracks (a movie in two languages, for example), pick the one you want before converting — MP4 handles multiple audio tracks fine, but players that only expose the first will confuse viewers.
- Soft subtitles in MKV may not survive into MP4 as expected: many rips use ASS or PGS streams that MP4 players ignore. If subtitles matter, check the output or burn them into the picture during conversion.
- If the MKV is 4K with HEVC video, an H.264 MP4 gives the widest compatibility but a noticeably bigger file; when your TV or editor supports HEVC, prefer an H.265 MP4 profile to keep the size down.