Video Converter
Convert between MP4, WebM, MKV, MOV, AVI, FLV, 3GP and animated GIF. FFmpeg runs as WebAssembly inside this tab, so nothing is uploaded.
Drop a video here
MP4, WebM, MOV, MKV, AVI, FLV, 3GP or WMV · up to 500 MB
About this tool
Converts video between MP4, WebM, MKV, MOV, AVI, FLV and 3GP, or turns a clip into an animated GIF, using a WebAssembly build of FFmpeg that runs inside the page. Nothing is uploaded, which matters when the footage is not yours to send to a stranger's server.
How to use it
- 1Drop a video file.
- 2Pick the output format, the quality and the resolution.
- 3Trim to a section first if you only need part of it, which also makes the encode much quicker.
- 4Convert, then download.
Good to know
WebM here is VP8, not VP9
The VP9 encoder in this WebAssembly build traps at every resolution and setting that was tried, so WebM is encoded with VP8 and Vorbis. VP8 files are larger than VP9 at the same quality, but they play everywhere WebM plays and, unlike VP9 here, they actually finish.
The first conversion downloads the engine
FFmpeg compiled to WebAssembly is around 32 MB. It downloads once, is cached afterwards, and is the reason the first conversion in a session takes longer to start than the rest.
GIF is made in two passes
A palette is generated from the footage first, then applied. Doing it in one pass is possible and needs well over a gigabyte of memory for a short clip, which is more than a browser tab reliably has.