video / converter

MP4 to MKV Converter

Convert MP4 files to MKV format using a practical and suitable conversion workflow.

Input: MP4 Output: MKV Local-first processing

MP4 to MKV Converter

Choose one or more MP4 files. Each file is converted to MKV locally in your browser with the FFmpeg WebAssembly engine. Nothing is uploaded to a server.

Choose files to begin.

How this page works

Use this page to convert MP4 into MKV. The page describes the accepted input, the expected output, and any quality or compatibility issues that matter for this conversion.

Some conversions are mainly for compatibility, while others may change quality, layout, transparency, timing, metadata, or editability.