Classy icons crafted according to Microsoft guidelines. Available in PNG and SVG. Free for a link
Feather Icons - Simply beautiful open source icons
Flat Icons - 20,000 unique, customizable icons with free lifetime updates
Streamline icons - The world’s largest icon pack library - 100k icons and illustrations.
Icons8 - Free app for Mac & Windows already containing 39,800 icons. Allows to search and import icons…
Heroicons - Beautiful, free SVG icons from the makers of Tailwind CSS.
IconBros - Free and continuously growing high quality icons