webp images having 85% of jpg images size.

Vitepress supporting webp images without any fallback for support of older browsers. But support of browsers in 2025 is like 🟢 , check https://caniuse.com/?search=webp . We are not having internet explorer in browsers list in analytics and there is some Safari 16 which started support in 20222.

We can use several possibilities to convert images:

Cwebp

download here as archive https://storage.googleapis.com/downloads.webmproject.org/releases/webp/index.html
copy /bin/cwebp to /usr/local/bin

cwebp image.jpg -o image.webp

Or some web solution.