Video to MKV Converter - For Media Servers & Plex

Convert videos to MKV format with multiple tracks, subtitles, and chapters. Perfect for Plex, Jellyfin, and media libraries. Private, browser-based.

Select Video

Drop video here or click to browse

MP4, AVI, MOV, WebM, WMV, FLV, and more

Privacy

All processing happens in your browser using FFmpeg WebAssembly. Your videos never leave your device—completely private and secure.

Related Tools

Video to MP4 - Universal format
Video to WebM - Web videos
Compress Video - Reduce file size
Trim Video - Cut sections
Extract Audio - Get MP3

Video to AVI Converter - For Legacy Wind…

Video to OGV Converter - Open Source The…

AVI to MP4 Converter - Play AVI Files An…

GIF to Video Converter - Convert GIFs to…

WMV to MP4 Converter - Windows Media to …

View all Video transcoders →

Frequently Asked Questions

MKV (Matroska) is an open-source video container that can hold unlimited video, audio, subtitle, and chapter tracks in a single file. It's the preferred format for media servers like Plex, Jellyfin, and Emby because it preserves all content streams without transcoding. You can switch between multiple audio languages and subtitles without separate files.

Most modern streaming devices support MKV: Roku, Apple TV, Fire TV, Chromecast, and Nvidia Shield all play MKV files directly or via media server apps. However, web browsers don't support MKV natively—use MP4 for web playback. MKV excels at local network streaming through media servers.

MKV supports features movie collectors need: multiple audio tracks (English, commentary, foreign languages), multiple subtitle tracks (forced, full, SDH), chapter markers, and attachments like custom fonts. MP4 technically supports some of these but with poor software compatibility. For Plex/Jellyfin libraries, MKV is the standard.

For archiving high-quality sources (Blu-ray rips, 4K content), use 'Best Quality'. For most movie collections, 'High Quality' provides excellent results at 30-40% smaller file sizes. Use 'Smaller File' for TV shows or content you're less concerned about preserving perfectly. 'Smallest File' is good for low-priority content or storage-limited situations.

No, this basic converter creates single-track MKV files with H.264 video and AAC audio. For adding multiple tracks, embedding subtitles, or advanced MKV features, use desktop software like MKVToolNix (free, powerful GUI tool) or HandBrake. This browser tool focuses on simple format conversion.

Keep 'Original' to preserve source quality for archiving. Choose 1080p for most TV viewing—it's the sweet spot for quality and file size. Use 720p for older TV shows or to save storage space (50% smaller than 1080p). Only use 480p if you have severe storage constraints or are watching on very small screens.

Yes, any re-encoding reduces quality slightly. At 'Best Quality' or 'High Quality' settings, the loss is visually imperceptible on most content. If your source is already H.264 in another container (MP4, MOV), consider using MKVToolNix to 'remux' instead—this copies video streams without re-encoding for zero quality loss and much faster processing.

Completely private. All processing happens in your browser using FFmpeg WebAssembly. Your video files never leave your device—no server uploads, no cloud processing, no data collection. You can verify this by disconnecting your internet after the page loads; conversion still works.

Browser-based WebAssembly video encoding is 10-50x slower than native desktop applications. A 10-minute video might take 30-60 minutes to convert. For large collections, frequent use, or time-sensitive work, use desktop tools like HandBrake (free) or FFmpeg. This browser tool is best for occasional conversions without installing software.

Converting (what this tool does) re-encodes video, which takes time and reduces quality slightly. Remuxing copies video/audio streams into a new container without re-encoding—it's instant and lossless. If you're just changing MP4 to MKV with the same codecs, use MKVToolNix to remux instead for better results.

Video to MKV Converter - For Media Servers & Plex

Select Video

Output Quality

Output Resolution

Conversion Complete

Privacy

Related Tools

Related Tools