Lucide is an open-source icon library: a set of more than 1,600 icons delivered as SVG files (scalable vector graphics, images described as lines and curves, so they stay sharp at any size). It is a community project and a fork of Feather Icons; Eric Fennis created it, and Karsa Rigó and Jakob Guddas maintain it.
Every icon follows a written design language: a 24 by 24 pixel canvas, a 1-pixel safe zone at the edges, 2-pixel strokes with round joins and caps, rounded corners, and at least 2 pixels between separate elements. Developers install official packages for plain web pages, React, React Native, Vue, Svelte, Preact, Solid, Angular and Astro, or use the static SVG files, and set color, size and stroke width in code. The packages are tree-shakable: the build tool keeps only the icons that the code imports, so unused icons add nothing to the shipped application.
Lucide is free and open source under the ISC License, a short permissive license similar to the MIT License.