Video Converter
Convert between MP4, WebM, and GIF, and optionally trim a clip — processed entirely in your browser using a WebAssembly build of FFmpeg. The first use on any visit downloads a one-time ~31MB engine (cached after that); videos up to 200 MB are never uploaded to a server.
This page doesn't show ads — it requires browser security settings (cross-origin isolation) that aren't compatible with third-party ad content.
Click to upload or drag and drop
MP4, WebM, MOV, AVI, MKV, or other common video formats
Why this page loads a large file first
Video processing is genuinely heavy work — this tool loads a real build of FFmpeg compiled to WebAssembly (~31MB, downloaded once and cached by your browser), the same engine behind most video conversion software. That's a meaningfully larger download than this site's other tools, and processing itself can take anywhere from a few seconds to several minutes depending on your device and the video's length and resolution.
Practical limits
Everything runs in your browser tab's own memory, which has real limits — WebAssembly itself caps addressable memory at 2GB, and performance degrades well before that point. This tool enforces a 200 MB file size limit to keep results from hanging your tab, and even files well under that limit can take a while for longer or higher-resolution clips.
About the GIF option
Converting to GIF automatically reduces the frame rate to 10fps and scales the width to 480px, since GIF has no real video compression — an unscaled, full-framerate GIF from typical footage would be enormous. GIFs also never include audio, since the format doesn't support it.
Frequently asked questions
Why does this tool download something before it can convert my video?
It loads a real, WebAssembly-compiled build of FFmpeg — the same engine most video software is built on — since browsers have no built-in way to transcode video formats. That download is roughly 31MB, happens once per visit, and is cached by your browser afterward.
Why doesn't this page show ads?
Video processing this heavy requires a browser security mode (cross-origin isolation) that most third-party ad content isn't compatible with, so this specific page runs without ads rather than risk breaking the conversion.
How large a video can I convert?
Up to 200MB. Processing happens entirely in your browser tab's own memory, which has real limits — very large or long videos can be slow or, on lower-memory devices, fail to complete.
Can I trim without converting the format?
Choose the same format as your source file and set a trim start and/or end time — the file will be re-encoded to that format with just the trimmed range kept.