What are some alternatives?
When comparing Flaticon and Font Squirrel, you can also consider the following products
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!
Google Fonts - Making the web more beautiful, fast, and open through great typography
IcoMoon - IcoMoon is an icon management tool that is build to provide iconography.
Fonts.com - Fonts.com provides the biggest and best selection of high quality desktop and web fonts. Try, buy and download classics like Helvetica, Univers, Frutiger, Trade Gothic and Avenir along with popular new fonts like Soho and Neo. Find your type!
IconPharm - IconPharm is a library of open source icons with recoloring and resizing tools.
Typekit - This will change the way you design websites. Add a line of code to your pages and choose from hundreds of web fonts. Simple, bulletproof, standards compliant.