Phosphor Icons is a free, open-source set of 9,000+ icons available in six weights (Thin, Light, Regular, Bold, Fill, and Duotone), drawn on a 16x16 base grid.
Switching all six weights through a single prop (rather than importing a separate icon per weight) makes it trivial to match icon boldness to surrounding type weight across a design.
A strong default for products that want one icon vendor to cover both a light, airy UI and a bold, high-contrast UI without switching libraries.
MIT licensed and free for commercial use; the Duotone weight in particular is uncommon among free icon sets and gives interfaces a more premium look than flat outline icons alone.
