WebM Builder is a simple Web interface made to generate batch scripts for simple VP8 WebM video encoding via FFmpeg on Windows.
Enter the encoding parameters on the page and download the resulting script. FFmpeg must be accessible via the PATH environment variable or be in the same directory.
WebM Builder easily runs locally in any modern Web browser with Javascript enabled. It is also hosted online.
For more advanced and multi-platform WebM encoding on the desktop, including VP9 and AV1 support, see Webbum.