Each icon font library has their own icons and no iconset is created equal. But with so many to choose from it can be difficult finding the best one to suit a new project.
GlyphSearch was made as a way to visually filter through icons to find the best one for your current project. It’s completely free and includes many of the most popular icon sets including Font Awesome, Glyphicons, Foundation, and even Octicons.
You can browse the site by a particular icon set or you can enter keywords like “facebook” for an FB social icon. Source code is also offered and easy to copy whether you need it as full HTML markup or something to embed within CSS.
The entire search engine has been completely open sourced with a full GitHub repository open to the public. This means you could even recompile the site itself to run locally on your own server!
In its current state GlyphSearch provides an incredible resource for all designers. New icon fonts may be added in the future but at the moment I think this site represents the perfect place to locate anything you need from the most popular open source iconfonts on the web.
Also if you’re looking for related webapps definitely check out FontCDN for searchable web fonts + Bootswatch for free Bootstrap themes.