Modern Font Stacks provides beautiful system font stacks that don´t require downloading of fonts! The font stacks are organized by typeface classifications, like System UI, Transitional, Old Style, Humanist, Geometric Humanist, Classical Humanist, Neo-Grotesque, Monospace Slab Serif, Monospace Code, Industrial, Rounded Sans, Slab Serif, Antique, Didone, Handwritten.
ionicons is a free set of 1,300 icons. You can get each one easily by clicking on the icon and then download the SVG. There is also a search function for icons.
Feathericons is a set of 287 open source icons. Clicking on an icon will download the SVG. Searching for icons is supported.
URL-encoder for SVG by yoksel. It encodes the SVG with encodeURIComponent(), which allows you to style the SVG inline within your CSS file after encoding. You cannot do that with base64 encoded inline images from SVG´s.
randoma11y.com by Adam Morse and John Otander uses a palette with 156 individual colors which allow to randomly create accessible color pairings with a high contrast of 4.5 or greater.
colorable.jxnblk.com is a full page layout that shows a background and a text color with its contrast value.