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MKV to MP4 Converter

Convert MKV to MP4 without quality loss. Fast copy if codecs compatible, otherwise H.264 re-encode. 100% private, no upload. Convert Matroska files for phones, TVs, and web.

🔒 No upload⚡ Fast MP4Free forever
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Drop MKV file here or click to browse
MKV → MP4 · Private · Max 1GB

How to convert MKV to MP4 in 3 steps

  1. Drop your MKV file — File stays on device, never uploaded. Works offline after first load.
  2. We auto-select MP4 — For mkv-to-mp4, we pre-select MP4 output. You can change quality, resolution, rotate.
  3. Convert & download — Click Convert. Fast remux uses -c copy when possible (instant), otherwise H.264 + AAC re-encode.

Why private matters: Wedding videos, work recordings, voice memos — uploading leaks them. Here, ffmpeg.wasm runs locally. No server copy.

FAQ: MKV to MP4

Is MKV to MP4 private?

Yes. ffmpeg.wasm runs in your browser tab. No upload endpoint exists. Your file never leaves your computer.

Is it free? Watermark?

Free forever, no watermark, no account. Supported by ads after you click Accept.

Max file size?

Best under 500MB. Hard limit 1GB. For larger, use desktop Handbrake/Shutter Encoder.

Will quality drop?

If we can fast-remux (same codec, just changing container), no loss and instant. If we must re-encode (e.g., MKV→MP4 with different codec), we use CRF 23 (Balanced) — visually lossless for most.

Other converters: MP4 to MP3 · MOV to MP4 · MP4 to GIF · Remove Audio · Compress Video
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