{"$schema":"https://toolsly.tools/schemas/tool-manifest-v1.json","generated":"2026-06-02T15:45:19.755Z","discovery":{"catalog":"https://toptool.io/tools.json","llmsTxt":"https://toptool.io/llms.txt","sitemap":"https://toptool.io/sitemap.xml"},"relatedTools":[{"slug":"mkv-to-mp4","name":"MKV to MP4","url":"https://toptool.io/mkv-to-mp4"},{"slug":"video-trimmer","name":"Video Trimmer","url":"https://toptool.io/video-trimmer"},{"slug":"video-compress","name":"Compress Video","url":"https://toptool.io/video-compress"},{"slug":"mp4-to-webm","name":"MP4 to WebM","url":"https://toptool.io/mp4-to-webm"},{"slug":"mp4-to-mov","name":"MP4 to MOV","url":"https://toptool.io/mp4-to-mov"},{"slug":"mp4-to-gif","name":"MP4 to GIF","url":"https://toptool.io/mp4-to-gif"},{"slug":"mp4-to-mp3","name":"MP4 to MP3","url":"https://toptool.io/mp4-to-mp3"},{"slug":"mp4-to-wav","name":"MP4 to WAV","url":"https://toptool.io/mp4-to-wav"}],"kind":"converter","slug":"mp4-to-mkv","name":"MP4 to MKV","description":"Remux MP4 to Matroska (MKV) — fast, lossless, no re-encoding.","longDescription":"Repackage an MP4 file into an MKV container without re-encoding the video or audio streams. Because nothing is decoded — the existing streams are just copied into a new container — the conversion is very fast and there is no quality loss. MKV is a flexible open container that supports multiple audio tracks, subtitles, and chapters; it's popular for media libraries and home theater setups. The conversion runs locally in your browser via ffmpeg.wasm, so the file never leaves your device. For best results keep inputs under about 500 MB.","category":"video","categoryName":"Video","keywords":["mp4 to mkv","convert mp4 to mkv","mp4 to mkv converter","mp4 to mkv online","mp4 to mkv free","online mp4 to mkv","change mp4 to mkv","mp4 mkv converter","free mp4 to mkv","online mp4 to mkv converter","remux mp4 to mkv","mp4 to matroska"],"url":"https://toptool.io/mp4-to-mkv","runsOn":"client","multiple":false,"batch":false,"input":{"type":"file","extensions":[".mp4"],"mimeTypes":["video/mp4"]},"output":{"type":"file","extension":".mkv","mimeType":"video/x-matroska"},"options":[],"invocation":{"webUi":"https://toptool.io/mp4-to-mkv","api":null,"notes":"Currently runs client-side in the user's browser. Drop a file on the UI at `webUi` and download the converted result. A remote MCP/REST API is planned."}}