What is Base UI and why are Developers switching to it?

So, what exactly is Base UI? Base UI is an open-source library of unstyled, accessible UI components for React. It is built by a team that includes contributors from MUI, Radix, and Floating UI. It ships with zero styles. No colors, no fonts, no spacing. Just the behavior: keyboard navigation, focus management, ARIA, all handled correctly. How it looks is entirely your call. Most UI libraries make decisions for you. They pick the colors, the spacing, the component shape. You work inside those decisions. Base UI flips this. It gives you the behavior, the keyboard handling, the accessibility logic, and nothing else. Every visual decision, from border radius to hover state, stays with you. Base UI v1.0.0 reached stable status in 2025, shipping with 35 unstyled components. It has been picking up serious traction in the React world since then. What’s the problem with traditional UI libraries If you have spent time with Floating UI or Chakra UI, you already know the frustration. The defaults