Convert videos between MP4, WebM, MOV, MKV, and more, processed entirely in your browser, files never uploaded.
Your video is converted locally with FFmpeg running in your browser. Nothing is uploaded; the file never leaves your device. First use downloads the ~31 MB engine once. Files up to 200 MB.
Accepts direct media links only (ending in .mp4, .webm, .mov …). Platform pages (YouTube, TikTok, Instagram and similar) are not supported; those require downloader tooling this site does not provide. URL files stream through our server once; uploaded files never leave your device.
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Video format problems are everywhere: a camera that records MOV that your editor refuses, a WebM clip that won't play on an older device, an MKV file an app can't open. This converter re-encodes your video into the container and codec combination you need: MP4 with H.264 video and AAC audio for maximum compatibility, WebM with VP9 and Opus for efficient web embedding, plus MOV, MKV, and AVI for specific workflows.
Under the hood it runs FFmpeg compiled to WebAssembly, executing directly in your browser tab. Unlike online converters that upload your footage to a server, process it who-knows-where, and keep copies, this tool never transmits your file anywhere. That makes it a better fit for private footage, draft material, or anything you simply don't want on a third-party server.
Re-encoding is a full conversion, so quality and size depend on the target format and the source material. For shrinking file size rather than changing format, the Video Compressor is the better tool. Need just a segment? Use the Video Trimmer.
No. Conversion happens entirely in your browser using a WebAssembly build of FFmpeg. Your file is read into browser memory, processed locally, and returned to you as a download; it never leaves your device.
Files up to 200 MB are supported. Browser-based processing is limited by your device memory, so very long or high-resolution videos may fail on machines with little RAM. Short clips and typical recordings convert comfortably.
MP4 (H.264 + AAC) plays essentially everywhere: phones, editors, browsers, social platforms. Choose WebM when you want smaller files for the web and control where it plays. MOV, MKV, and AVI exist for specific editing and archival workflows.
Video re-encoding is genuinely heavy computation, and browser-based FFmpeg is slower than a native desktop app. A one-minute clip typically takes under a minute; a 30-minute video can take considerably longer depending on your CPU.
Any format change re-encodes the video, which can introduce slight generational loss. Staying in a modern format like H.264 or VP9 at default settings keeps the change visually negligible for most footage.