MKV to MP4
Convert MKV to MP4 in your browser. This free MKV to MP4 converter keeps Matroska files on your device — no upload, no login, one file at a time.
Drop an MKV file here
or
One file at a time · Processed only on this device · No batch queue
What this tool supports
- Input: one .mkv (Matroska) file from your device
- Output: a single .mp4 download with the same base name
- Local only — no account, no cloud upload, no batch queue
- Tries a fast remux (stream copy) first; falls back to H.264 / AAC when the codecs cannot sit in MP4
- Speed and success depend on your hardware and the streams inside the MKV
How to convert MKV to MP4
- Drop your MKV onto the box above, or click Choose file.
- Click Convert to MP4. ffmpeg.wasm runs entirely in this tab.
- Download the MP4 when ready. The original Matroska file never left your device.
Related: MOV to MP4 without upload (same privacy model) · MOV / QuickTime guide.
FAQ
- Is this a free MKV to MP4 converter?
- Yes. No login, no paywall, and no server-side usage meter on this page.
- Are my MKV files uploaded?
- No. Conversion is local with ffmpeg.wasm. We do not offer batch upload or a cloud queue.
- Will remux always work?
- Only when the video/audio codecs are already MP4-friendly. Otherwise the tool re-encodes to H.264 and AAC so you still get a playable file.
- Does converting MKV to MP4 reduce quality?
- Remux keeps pixels and audio samples identical. Re-encode to H.264/AAC can add a small generation loss, but it is only used when stream copy cannot produce a playable MP4.
- Looking for QuickTime / MOV?
- Use MOV to MP4 on the home page — same local pattern. Guides: QuickTime → MP4, without upload.