Flaticon - A database of free vector icons.
Iconoir - A diverse and open-source library with 900+ icons
Font Awesome - Font Awesome makes it easy to add vector icons and social logos to your website. And version 5 is redesigned and built from the ground up!
Heroicons - Beautiful, free SVG icons from the makers of Tailwind CSS.
IconArchive - Search through more than 735,000 free icons. Browse icons by category, artist, popularity, date. Organize and share your favorites.
IconStore - Free icon packs by first-class designers