Convert MP4 to MKV Online Free

Convert MP4 to MKV instantly in your browser. No uploads needed - your files stay private on your device.

drag & drop files here

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images, videos, audio, documents - all processed locally

Why convert MP4 to MKV?

  • MKV may offer better compatibility with your target platform
  • Optimize video for web streaming or social media
  • Reduce file size while maintaining acceptable quality
  • Prepare video for specific devices or players

How to convert MP4 to MKV

1

Upload your file

Drag and drop your MP4 file onto the converter, or click to browse your files.

2

Select MKV as output

Choose MKV from the format dropdown. The converter will automatically detect your file type.

3

Convert instantly

Your file is processed entirely in your browser using WebAssembly. No upload needed.

4

Download your file

Click the download button to save your converted MKV file.

About MP4 format

MP4 is the most widely used video container format, supporting H.264/H.265 video codecs and AAC audio. It offers excellent compression while maintaining high quality, making it the standard for streaming, downloads, and video sharing. Nearly every device, platform, and media player supports MP4 playback.

Pros

  • +Universal device and platform support
  • +Excellent compression with H.264/H.265
  • +Supports subtitles and multiple audio tracks

Cons

  • -Lossy compression affects quality
  • -Editing can be complex without re-encoding
  • -Some advanced codecs may not play everywhere

About MKV format

MKV (Matroska) is a flexible, open-standard container format that can hold virtually unlimited video, audio, and subtitle tracks. Popular for high-definition video distribution, MKV supports modern codecs and features like chapters and metadata. It's the format of choice for video enthusiasts.

Pros

  • +Supports virtually any codec
  • +Multiple audio and subtitle tracks
  • +Chapter and metadata support

Cons

  • -Limited device playback support
  • -Not suitable for streaming
  • -May require codec packs on some systems

Frequently asked questions

Is it safe to convert MP4 to MKV online?
Yes, Convt processes your files entirely in your browser using WebAssembly. Your files never leave your device - no data is uploaded to any server. This makes it completely private and secure.
How long does MP4 to MKV conversion take?
Conversion is typically instant for small to medium files. Larger files may take a few seconds depending on your device's processing power. Since everything runs locally, speed depends on your hardware rather than internet connection.
Is there a file size limit for conversion?
There's no artificial file size limit. However, very large files (over 500MB for video, 100MB for images) may strain your browser's memory. For best results, ensure you have enough available RAM.
Do I need to install any software?
No installation required. Convt runs entirely in your web browser. It works on any modern browser including Chrome, Firefox, Safari, and Edge on desktop and mobile devices.
Can I convert multiple files at once?
Yes, you can add multiple files to the converter and process them all. Each file will be converted individually and you can download them separately or together.
Can I extract audio from my MP4 video?
Yes! Select an audio format (MP3, WAV, OGG, etc.) as the output format to extract just the audio track from your video file.

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