Nucleo - Commercial vector icons and accompanying apps to manage and customize them.
Heroicons - Beautiful, free SVG icons from the makers of Tailwind CSS.
Streamline icons - The world’s largest icon pack library - 100k icons and illustrations.
IconStore - Free icon packs by first-class designers
Freepik - More than a million free vectors, PSD, photos and free icons. Exclusive freebies and all graphic resources that you need for your projects
Iconoir - A diverse and open-source library with 900+ icons