Routes are configured as the first argument to createBrowserRouter. At a minimum, you need a path and component:
import { createBrowserRouter } from "react-router";
function Root() {
  return <h1>Hello world</h1>;
}
const router = createBrowserRouter([
  { path: "/", Component: Root },
]);
Here is a larger sample route config:
createBrowserRouter([
  {
    path: "/",
    Component: Root,
    children: [
      { index: true, Component: Home },
      { path: "about", Component: About },
      {
        path: "auth",
        Component: AuthLayout,
        children: [
          { path: "login", Component: Login },
          { path: "register", Component: Register },
        ],
      },
      {
        path: "concerts",
        children: [
          { index: true, Component: ConcertsHome },
          { path: ":city", Component: ConcertsCity },
          { path: "trending", Component: ConcertsTrending },
        ],
      },
    ],
  },
]);
Route objects define the behavior of a route beyond just the path and component, like data loading and actions. We'll go into more detail in the Route Object guide, but here's a quick example of a loader.
import {
  createBrowserRouter,
  useLoaderData,
} from "react-router";
createBrowserRouter([
  {
    path: "/teams/:teamId",
    loader: async ({ params }) => {
      let team = await fetchTeam(params.teamId);
      return { name: team.name };
    },
    Component: Team,
  },
]);
function Team() {
  let data = useLoaderData();
  return <h1>{data.name}</h1>;
}
Routes can be nested inside parent routes through children.
createBrowserRouter([
  {
    path: "/dashboard",
    Component: Dashboard,
    children: [
      { index: true, Component: Home },
      { path: "settings", Component: Settings },
    ],
  },
]);
The path of the parent is automatically included in the child, so this config creates both "/dashboard" and "/dashboard/settings" URLs.
Child routes are rendered through the <Outlet/> in the parent route.
import { Outlet } from "react-router";
export default function Dashboard() {
  return (
    <div>
      <h1>Dashboard</h1>
      {/* will either be <Home> or <Settings> */}
      <Outlet />
    </div>
  );
}
Omitting the path in a route creates new Nested Routes for its children without adding any segments to the URL.
createBrowserRouter([
  {
    // no path on this parent route, just the component
    Component: MarketingLayout,
    children: [
      { index: true, Component: Home },
      { path: "contact", Component: Contact },
    ],
  },
  {
    path: "projects",
    children: [
      { index: true, Component: ProjectsHome },
      {
        // again, no path, just a component for the layout
        Component: ProjectLayout,
        children: [
          { path: ":pid", Component: Project },
          { path: ":pid/edit", Component: EditProject },
        ],
      },
    ],
  },
]);
Note that:
Home and Contact will be rendered into the MarketingLayout outletProject and EditProject will be rendered into the ProjectLayout outlet while ProjectsHome will not.Index routes are defined by setting index: true on a route object without a path.
{ index: true, Component: Home }
Index routes render into their parent's Outlet at their parent's URL (like a default child route).
import { createBrowserRouter } from "react-router";
createBrowserRouter([
  // renders at "/"
  { index: true, Component: Home },
  {
    Component: Dashboard,
    path: "/dashboard",
    children: [
      // renders at "/dashboard"
      { index: true, Component: DashboardHome },
      { path: "settings", Component: DashboardSettings },
    ],
  },
]);
Note that index routes can't have children.
A route with just a path and no component creates a group of routes with a path prefix.
createBrowserRouter([
  {
    // no component, just a path
    path: "/projects",
    children: [
      { index: true, Component: ProjectsHome },
      { path: ":pid", Component: Project },
      { path: ":pid/edit", Component: EditProject },
    ],
  },
]);
This creates the routes /projects, /projects/:pid, and /projects/:pid/edit without introducing a layout component.
If a path segment starts with : then it becomes a "dynamic segment". When the route matches the URL, the dynamic segment will be parsed from the URL and provided as params to other router APIs.
{
  path: "teams/:teamId",
  loader: async ({ params }) => {
    // params are available in loaders/actions
    let team = await fetchTeam(params.teamId);
    return { name: team.name };
  },
  Component: Team,
}
import { useParams } from "react-router";
function Team() {
  // params are available in components through useParams
  let params = useParams();
  // ...
}
You can have multiple dynamic segments in one route path:
{
  path: "c/:categoryId/p/:productId";
}
You can make a route segment optional by adding a ? to the end of the segment.
{
  path: ":lang?/categories";
}
You can have optional static segments, too:
{
  path: "users/:userId/edit?";
}
Also known as "catchall" and "star" segments. If a route path pattern ends with /* then it will match any characters following the /, including other / characters.
{
  path: "files/*";
  loader: async ({ params }) => {
    params["*"]; // will contain the remaining URL after files/
  };
}
You can destructure the *, you just have to assign it a new name. A common name is splat:
const { "*": splat } = params;
Next: Route Object