The most convenient way right now to share SVG in QGIS is to use QGIS Resource Sharing plugin (you can install it from QGIS Plugin Manager). Maki icons are shipped into one of the approved repositories that you can use them right away.
The size of an SVG file depends on how complex it is, not how "large" it is. .element { background-image: url(/images/image.svg); } And remember, no matter what format you get when you download something like that, you can generally Ready to use SVG icons for the web. Don't forget to load the basic CSS file. HTML.
Designers, download the design stuff for free — icons, photos, UX illustrations, and music for your videos.
