TanStack Router is a router for React applications from TanStack, an open-source project run by TanStack LLC. A router is the part of a single-page web app that decides which screen and data to show for each URL, without loading a new page from the server. TanStack Router is built around TypeScript: paths, route parameters, search parameters, loaders and links are all type-checked, so a broken link fails in the editor instead of in production.
Routes are defined once, for example as route files from which a route tree file is generated. Search parameters in the URL are parsed, validated and typed, so filters, pagination and tabs survive page refreshes, the back button, bookmarks and shared links. Route loaders fetch data before a screen renders, with built-in caching, and the router can preload code and data when a user hovers over or focuses a link. It also supports nested layouts, code splitting and error boundaries. TanStack Start, a full-stack framework built on the same routes, adds server-side rendering, streaming and server functions.
It is free and open source under the MIT license.