Why convert MKV to MP4?
MKV can hold many audio, subtitle, and attachment streams, but some phones, browsers, TVs, and editing tools do not support the container. MP4 is more predictable for everyday playback and uploads. This browser tool prioritizes a simple, compatible video file.
Which MKV tracks are kept?
The first video track and, when present, the first audio track are converted to H.264 and AAC. Extra audio tracks, embedded subtitles, chapters, fonts, and attachments are not copied. Use a desktop media tool when those additional tracks must be preserved.
- Tracks kept
- First video and first audio
- Video / audio
- H.264 / AAC
- Not copied
- Subtitles and attachments
How to convert MKV to MP4
- 1
Choose one MKV video up to 100 MB.
- 2
Select an output quality and start the local browser conversion.
- 3
Preview and download the converted .mp4 file.
Frequently asked questions
Will subtitles from my MKV appear in the MP4?
No. This converter does not copy or burn in subtitle tracks. It creates a simple MP4 from the first video and optional first audio track.
Is this MKV to MP4 converter private?
Yes. The video is processed by WebAssembly inside your browser and is not uploaded to Free2Convert. Closing or refreshing the tab removes the working data.
Why can browser video conversion take several minutes?
Video decoding and encoding require substantial CPU and memory. Speed depends on the video duration, resolution, source codec, quality setting, and your device.