LinksConverterRepackage an MP4 into a Matroska MKV container — the flexible format that can hold multiple audio and subtitle tracks. Popular with media servers like Plex and Jellyfin.
MP4 (MPEG-4 Part 14) is the most widely supported video container on the planet. It packs H.264 or H.265 video with AAC audio into a single file that plays natively on iPhone, Android, Windows, macOS, web browsers, smart TVs, and every modern editor. Use MP4 when you need a finished, shareable video that will just work, anywhere, without re-encoding.
MKV (Matroska) is the power user’s container. It can hold unlimited video, audio, and subtitle tracks of any codec, which is why anime, Blu-ray rips, and multi-language films ship as MKV. The downside: phones, smart TVs, and most social platforms refuse to play MKV directly — you almost always need to remux to MP4.
Server-side ffmpeg + yt-dlp on auto-scaling workers. Most files finish in seconds, not minutes.
Every uploaded or fetched file is virus-scanned before it ever reaches your download.
Files live on encrypted S3 storage for 2 hours, then are permanently purged. We never log file contents.
Free for up to 10 conversions per hour with no account. Pro unlocks larger files and priority queue.
Drop a MP4 file from your device, or paste a public URL pointing to the MP4 you want to convert.
The output is pre-set to MKV. You can adjust quality or bitrate in the advanced options if you need a smaller file.
Click Convert. Our cloud workers fetch the MP4, scan it for malware, and run the MP4 → MKV pipeline.
A one-time pre-signed link appears as soon as the MKV is ready. The file is automatically deleted from our storage 2 hours later.
Browse other popular file conversions handled by the same pipeline.