Flaticon is the largest search engine of free icons in the world. Flaticon offers users, high-quality graphic designs: totally editable vectors carefully selected by our design team in order to provide our users with great content that can be used in both personal and commercial projects.
Icons8 is an icon pack software for Windows and Macintosh that is available as a free and paid version. All icons can be used for free but if you don’t purchase a license, you are required to link to the Icons8 website on pages or in programs that you use the icons in your projects.
3. ICON MONTSR
iconmonstr – free, monstrously big and continuously growing source of simple icons run by one creator. Its growing day by day. Created by Alexander Kahlkopf, a senior designer from Germany with over 15 years of professional experience in icon design.
4. FEATHER ICONS
Feather is a collection of simply beautiful open source icons. Each icon is designed on a 24×24 grid with an emphasis on simplicity, consistency, and flexibility.
5. MATERIAL ICONS
Material icons are delightful, beautifully crafted symbols for common actions and items. Download on desktop to use them in your digital products for Android, iOS, and web.
Font Awesome is a font and icon toolkit based on CSS and LESS. It was made by Dave Gandy for use with Twitter Bootstrap and later was incorporated into the BootstrapCDN. Font Awesome has a 20% market share among those websites which use third-party Font Scripts on their platform, ranking it second place after Google Fonts.
New icons are added daily by the creator community. Millions use Noun Project to simplify communication, across borders and around the world.
#Some honorable mentions: Iconfincder, IconMoon, Iconseeker, Fontello