Animated SVG animations (really just an svg element + animated css) are significantly smaller, more efficient, and crisper than equivalent GIF animations. I wrote about the difference between the two here: https://hackernoon.com/presenting-your-code-beautifully-fdba...

As I explained in the above article, this is already possible with asciinema + svg-term-cli (https://github.com/marionebl/svg-term-cli).

The one downside with animated SVGs is that they're not as compatible to be included anywhere as GIFs since they're really just html snippets.