MP4 to MKV Converter
Processing entirely on your device — large files may take a moment.
MP4 (H.264) is the universal video format: every phone records it, every browser, TV, editor and chat app plays it. MKV is ideal for archiving movies with multiple audio tracks and subtitles intact.
iLoveConverter processes everything locally on your computer, which makes it private and fast: no upload wait, no server storage, no limits. Add as many files as you like — batch conversion is built in.
How to convert MP4 to MKV
- 1
Select your files
Drag & drop your MP4 files onto the area above, or click to browse. You can add multiple files at once for batch conversion.
- 2
Convert instantly
Click "Convert to MKV". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted MKV file individually, or grab everything at once as a ZIP archive.
Frequently asked questions
Is this MP4 to MKV converter really free?
Yes — completely free, with no sign-up, no watermark and no daily conversion limits. The site is supported by advertising.
Are my files uploaded to a server?
No. The conversion runs entirely inside your browser using WebAssembly, so your files never leave your device — that is what makes it instant and private.
Does it work on Windows, Mac, iPhone and Android?
Yes. Anything with a modern browser works: Windows, macOS, Linux, Android and iOS. No software installation is required.
Is there a file size limit for MP4 to MKV?
The only limit is your device's memory, since nothing is uploaded. Files up to a few hundred megabytes work fine on a modern desktop browser; very large files simply take a little longer.