Routing

Astro uses file-based routing to generate your build URLs based on the file layout of your project src/pages/ directory.

Navigating between pages

Astro uses standard HTML <a> elements to navigate between routes. There is no framework-specific <Link> component provided.

src/pages/index.astro

<p>Read more <a href="/about/">about</a> Astro!</p>

<!-- With `base: "/docs"` configured -->
<p>Learn more in our <a href="/docs/reference/">reference</a> section!</p>

Static routes

.astro page components as well as Markdown and MDX Files (.md, .mdx) within the src/pages/ directory automatically become pages on your website. Each page’s route corresponds to its path and filename within the src/pages/ directory.

# Example: Static routes
src/pages/index.astro        -> mysite.com/
src/pages/about.astro        -> mysite.com/about
src/pages/about/index.astro  -> mysite.com/about
src/pages/about/me.astro     -> mysite.com/about/me
src/pages/posts/1.md         -> mysite.com/posts/1

Tip

There is no separate “routing config” to maintain in an Astro project! When you add a file to the src/pages/ directory, a new route is automatically created for you. In static builds, you can customize the file output format using the build.format configuration option.

Dynamic routes

An Astro page file can specify dynamic route parameters in its filename to generate multiple, matching pages. For example, src/pages/authors/[author].astro generates a bio page for every author on your blog. author becomes a parameter that you can access from inside the page.

In Astro’s default static output mode, these pages are generated at build time, and so you must predetermine the list of authors that get a corresponding file. In SSR mode, a page will be generated on request for any route that matches.

Static (SSG) Mode

Because all routes must be determined at build time, a dynamic route must export a getStaticPaths() that returns an array of objects with a params property. Each of these objects will generate a corresponding route.

[dog].astro defines the dynamic dog parameter in its filename, so the objects returned by getStaticPaths() must include dog in their params. The page can then access this parameter using Astro.params.

src/pages/dogs/[dog].astro

---
export function getStaticPaths() {
  return [
    { params: { dog: "clifford" }},
    { params: { dog: "rover" }},
    { params: { dog: "spot" }},
  ];
}

const { dog } = Astro.params;
---
<div>Good dog, {dog}!</div>

This will generate three pages: /dogs/clifford, /dogs/rover, and /dogs/spot, each displaying the corresponding dog name.

The filename can include multiple parameters, which must all be included in the params objects in getStaticPaths():

src/pages/[lang]-[version]/info.astro

---
export function getStaticPaths() {
  return [
    { params: { lang: "en", version: "v1" }},
    { params: { lang: "fr", version: "v2" }},
  ];
}

const { lang, version } = Astro.params;
---

This will generate /en-v1/info and /fr-v2/info.

Parameters can be included in separate parts of the path. For example, the file src/pages/[lang]/[version]/info.astro with the same getStaticPaths() above will generate the routes /en/v1/info and /fr/v2/info.

Decoding params

params returned by a getStaticPaths() function are not decoded. Use decodeURI() when you need to decode parameter values.

src/pages/[slug].astro

---
export function getStaticPaths() {
  return [
    { params: { slug: decodeURI("%5Bpage%5D") }}, // decodes to "[page]"
  ]
}
---

Learn more about getStaticPaths().

関連レシピ： Add i18n features (EN)

Rest parameters

If you need more flexibility in your URL routing, you can use a rest parameter ([...path]) in your .astro filename to match file paths of any depth:

src/pages/sequences/[...path].astro

---
export function getStaticPaths() {
  return [
    { params: { path: "one/two/three" }},
    { params: { path: "four" }},
    { params: { path: undefined }}
  ]
}

const { path } = Astro.params;
---

This will generate /sequences/one/two/three, /sequences/four, and /sequences. (Setting the rest parameter to undefined allows it to match the top level page.)

Rest parameters can be used with other named parameters. For example, GitHub’s file viewer can be represented with the following dynamic route:

/[org]/[repo]/tree/[branch]/[...file]

In this example, a request for /withastro/astro/tree/main/docs/public/favicon.svg would be split into the following named parameters:

{
  org: "withastro",
  repo: "astro",
  branch: "main",
  file: "docs/public/favicon.svg"
}

Example: Dynamic pages at multiple levels

In the following example, a rest parameter ([...slug]) and the props feature of getStaticPaths() generate pages for slugs of different depths.

src/pages/[...slug].astro

---
export function getStaticPaths() {
  const pages = [
    {
      slug: undefined,
      title: "Astro Store",
      text: "Welcome to the Astro store!",
    },
    {
      slug: "products",
      title: "Astro products",
      text: "We have lots of products for you",
    },
    {
      slug: "products/astro-handbook",
      title: "The ultimate Astro handbook",
      text: "If you want to learn Astro, you must read this book.",
    },
  ];

  return pages.map(({ slug, title, text }) => {
    return {
      params: { slug },
      props: { title, text },
    };
  });
}

const { title, text } = Astro.props;
---
<html>
  <head>
    <title>{title}</title>
  </head>
  <body>
    <h1>{title}</h1>
    <p>{text}</p>
  </body>
</html>

On-demand dynamic routes

For on-demand rendering with an adapter, dynamic routes are defined the same way: include [param] or [...path] brackets in your file names to match arbitrary strings or paths. But because the routes are no longer built ahead of time, the page will be served to any matching route. Since these are not “static” routes, getStaticPaths should not be used.

For on-demand rendered routes, only one rest parameter using the spread notation may be used in the file name (e.g. src/pages/[locale]/[...slug].astro or src/pages/[...locale]/[slug].astro, but not src/pages/[...locale]/[...slug].astro).

src/pages/resources/[resource]/[id].astro

---
export const prerender = false; // Not needed in 'server' mode
const { resource, id } = Astro.params;
---
<h1>{resource}: {id}</h1>

This page will be served for any value of resource and id: resources/users/1, resources/colors/blue, etc.

Modifying the [...slug] example for SSR

Because SSR pages can’t use getStaticPaths(), they can’t receive props. The previous example can be adapted for SSR mode by looking up the value of the slug param in an object. If the route is at the root (”/”), the slug param will be undefined. If the value doesn’t exist in the object, we redirect to a 404 page.

src/pages/[...slug].astro

---
const pages = [
  {
    slug: undefined,
    title: 'Astro Store',
    text: 'Welcome to the Astro store!',
  },
  {
    slug: 'products',
    title: 'Astro products',
    text: 'We have lots of products for you',
  },
  {
    slug: 'products/astro-handbook',
    title: 'The ultimate Astro handbook',
    text: 'If you want to learn Astro, you must read this book.',
  }
];

const { slug } = Astro.params;
const page = pages.find((page) => page.slug === slug);
if (!page) return Astro.redirect("/404");
const { title, text } = page;
---
<html>
  <head>
    <title>{title}</title>
  </head>
  <body>
    <h1>{title}</h1>
    <p>{text}</p>
  </body>
</html>

Redirects

Sometimes you will need to redirect your readers to a new page, either permanently because your site structure has changed or in response to an action such as logging in to an authenticated route.

You can define rules to redirect users to permanently-moved pages in your Astro config. Or, redirect users dynamically as they use your site.

Configured Redirects

追加： astro@2.9.0

You can specify a mapping of permanent redirects in your Astro config with the redirects value.

For internal redirects, this is a mapping of an old route path to the new route. As of Astro v5.2.0, it is also possible to redirect to external URLs that start with http or https and can be parsed:

astro.config.mjs

import { defineConfig } from "astro/config";

export default defineConfig({
  redirects: {
    "/old-page": "/new-page",
    "/blog": "https://example.com/blog"
  }
});

These redirects follow the same priority rules as file-based routes and will always take lower precedence than an existing page file of the same name in your project. For example, /old-page will not redirect to /new-page if your project contains the file src/pages/old-page.astro.

Dynamic routes are allowed as long as both the new and old routes contain the same parameters, for example:

{
  "/blog/[...slug]": "/articles/[...slug]"
}

Using SSR or a static adapter, you can also provide an object as the value, allowing you to specify the status code in addition to the new destination:

astro.config.mjs

import { defineConfig } from "astro/config";

export default defineConfig({
  redirects: {
    "/old-page": {
      status: 302,
      destination: "/new-page"
    },
    "/news": {
      status: 302,
      destination: "https://example.com/news"
    }
  }
});

When running astro build, Astro will output HTML files with the meta refresh tag by default. Supported adapters will instead write out the host’s configuration file with the redirects.

The status code is 301 by default. If building to HTML files the status code is not used by the server.

Dynamic redirects

On the Astro global, the Astro.redirect method allows you to redirect to another page dynamically. You might do this after checking if the user is logged in by getting their session from a cookie.

src/pages/account.astro

---
import { isLoggedIn } from "../utils";

const cookie = Astro.request.headers.get("cookie");

// If the user is not logged in, redirect them to the login page
if (!isLoggedIn(cookie)) {
  return Astro.redirect("/login");
}
---

Because Astro uses HTML streaming in on-demand rendering, redirects must be done at the page level, not inside child components.

Rewrites

追加： astro@4.13.0

A rewrite allows you to serve a different route without redirecting the browser to a different page. The browser will show the original address in the URL bar, but will instead display the content of the URL provided to Astro.rewrite().

Tip

For content that has permanently moved, or to direct your user to a different page with a new URL (e.g. a user dashboard after logging in), use a redirect instead.

Rewrites can be useful for showing the same content at multiple paths (e.g. /products/shoes/men/ and /products/men/shoes/) without needing to maintain two different source files.

Rewrites are also useful for SEO purposes and user experience. They allow you to display content that otherwise would require redirecting your visitor to a different page or would return a 404 status. One common use of rewrites is to show the same localized content for different variants of a language.

The following example uses a rewrite to render the /es/ version of a page when the /es-CU/ (Cuban Spanish) URL path is visited. When a visitor navigates to the URL /es-cu/articles/introduction, Astro will render the content generated by the file src/pages/es/articles/introduction.astro.

src/pages/es-cu/articles/introduction.astro

---
return Astro.rewrite("/es/articles/introduction");
---

Use context.rewrite() in your endpoint files to reroute to a different page:

src/pages/api.js

export function GET(context) {
  if (!context.locals.allowed) {
    return context.rewrite("/");
  }
}

If the URL passed to Astro.rewrite() emits a runtime error, Astro will show the overlay error in development and return a 500 status code in production. If the URL does not exist in your project, a 404 status code will be returned.

You can intentionally create a rewrite to render your /404 page, for example to indicate that a product in your e-commerce shop is no longer available:

src/pages/[item].astro

---
const { item } = Astro.params;

if (!itemExists(item)) {
  return Astro.rewrite("/404");
}
---

You can also conditionally rewrite based on an HTTP response status, for example to display a certain page on your site when visiting a URL that doesn’t exist:

src/middleware.mjs

export const onRequest = async (context, next) => {
  const response = await next();
  if (response.status === 404) {
    return context.rewrite("/");
  }
  return response;
}

Before displaying the content from the specified rewrite path, the function Astro.rewrite() will trigger a new, complete rendering phase. This re-executes any middleware for the new route/request.

See the Astro.rewrite() API reference for more information.

Route Priority Order

It’s possible for multiple defined routes to attempt to build the same URL path. For example, all of these routes could build /posts/create:

• ディレクトリsrc/pages/

  • […slug].astro
  • ディレクトリposts/

    • create.astro
    • [page].astro
    • [pid].ts
    • […slug].astro

Astro needs to know which route should be used to build the page. To do so, it sorts them according to the following rules in order:

• Astro reserved routes
• Routes with more path segments will take precedence over less specific routes. In the example above, all routes under /posts/ take precedence over /[...slug].astro at the root.
• Static routes without path parameters will take precedence over dynamic routes. E.g. /posts/create.astro takes precedence over all the other routes in the example.
• Dynamic routes using named parameters take precedence over rest parameters. E.g. /posts/[page].astro takes precedence over /posts/[...slug].astro.
• Pre-rendered dynamic routes take precedence over server dynamic routes.
• Endpoints take precedence over pages.
• File-based routes take precedence over redirects.
• If none of the rules above decide the order, routes are sorted alphabetically based on the default locale of your Node installation.

Given the example above, here are a few examples of how the rules will match a requested URL to the route used to build the HTML:

• pages/posts/create.astro - Will build only /posts/create
• pages/posts/[pid].ts - Will build /posts/abc, /posts/xyz, etc. But not /posts/create
• pages/posts/[page].astro - Will build /posts/1, /posts/2, etc. But not /posts/create, /posts/abc nor /posts/xyz
• pages/posts/[...slug].astro - Will build /posts/1/2, /posts/a/b/c, etc. But not /posts/create, /posts/1, /posts/abc, etc.
• pages/[...slug].astro - Will build /abc, /xyz, /abc/xyz, etc. But not /posts/create, /posts/1, /posts/abc, etc.

Reserved routes

Internal routes take priority over any user-defined or integration-defined routes as they are required for Astro features to work. The following are Astro’s reserved routes:

• _astro/: Serves all of the static assets to the client, including CSS documents, bundled client scripts, optimized images, and any Vite assets.
• _server_islands/: Serves the dynamic components deferred into a server island.
• _actions/: Serves any defined actions.

Pagination

Astro supports built-in pagination for large collections of data that need to be split into multiple pages. Astro will generate common pagination properties, including previous/next page URLs, total number of pages, and more.

Paginated route names should use the same [bracket] syntax as a standard dynamic route. For instance, the file name /astronauts/[page].astro will generate routes for /astronauts/1, /astronauts/2, etc, where [page] is the generated page number.

You can use the paginate() function to generate these pages for an array of values like so:

src/pages/astronauts/[page].astro

---
export function getStaticPaths({ paginate }) {
  const astronautPages = [
    { astronaut: "Neil Armstrong" },
    { astronaut: "Buzz Aldrin" },
    { astronaut: "Sally Ride" },
    { astronaut: "John Glenn" },
  ];

  // Generate pages from our array of astronauts, with 2 to a page
  return paginate(astronautPages, { pageSize: 2 });
}
// All paginated data is passed on the "page" prop
const { page } = Astro.props;
---
<!-- Display the current page number. `Astro.params.page` can also be used! -->
<h1>Page {page.currentPage}</h1>
<ul>
  <!-- List the array of astronaut info -->
  {page.data.map(({ astronaut }) => <li>{astronaut}</li>)}
</ul>

This generates the following pages, with 2 items to a page:

• /astronauts/1 - Page 1: Displays “Neil Armstrong” and “Buzz Aldrin”
• /astronauts/2 - Page 2: Displays “Sally Ride” and “John Glenn”

The page prop

When you use the paginate() function, each page will be passed its data via a page prop. The page prop has many useful properties that you can use to build pages and links between them:

interface Page<T = any> {
  /** array containing the page’s slice of data that you passed to the paginate() function */
  data: T[];
  /** metadata */
  /** the count of the first item on the page, starting from 0 */
  start: number;
  /** the count of the last item on the page, starting from 0 */
  end: number;
  /** total number of results */
  total: number;
  /** the current page number, starting from 1 */
  currentPage: number;
  /** number of items per page (default: 10) */
  size: number;
  /** number of last page */
  lastPage: number;
  url: {
    /** url of the current page */
    current: string;
    /** url of the previous page (if there is one) */
    prev: string | undefined;
    /** url of the next page (if there is one) */
    next: string | undefined;
    /** url of the first page (if the current page is not the first page) */
    first: string | undefined;
    /** url of the last page (if the current page in not the last page) */
    last: string | undefined;
  };
}

The following example displays current information for the page along with links to navigate between pages:

src/pages/astronauts/[page].astro

---
// Paginate same list of `{ astronaut }` objects as the previous example
export function getStaticPaths({ paginate }) { /* ... */ }
const { page } = Astro.props;
---
<h1>Page {page.currentPage}</h1>
<ul>
  {page.data.map(({ astronaut }) => <li>{astronaut}</li>)}
</ul>
{page.url.first ? <a href={page.url.first}>First</a> : null}
{page.url.prev ? <a href={page.url.prev}>Previous</a> : null}
{page.url.next ? <a href={page.url.next}>Next</a> : null}
{page.url.last ? <a href={page.url.last}>Last</a> : null}

Learn more about the pagination page prop.

Nested Pagination

A more advanced use-case for pagination is nested pagination. This is when pagination is combined with other dynamic route params. You can use nested pagination to group your paginated collection by some property or tag.

For example, if you want to group your paginated Markdown posts by some tag, you would use nested pagination by creating a /src/pages/[tag]/[page].astro page that would match the following URLS:

• /red/1 (tag=red)
• /red/2 (tag=red)
• /blue/1 (tag=blue)
• /green/1 (tag=green)

Nested pagination works by returning an array of paginate() results from getStaticPaths(), one for each grouping.

In the following example, we will implement nested pagination to build the URLs listed above:

src/pages/[tag]/[page].astro

---
export function getStaticPaths({ paginate }) {
  const allTags = ["red", "blue", "green"];
  const allPosts = Object.values(import.meta.glob("../pages/post/*.md", { eager: true }));
  // For every tag, return a `paginate()` result.
  // Make sure that you pass `{ params: { tag }}` to `paginate()`
  // so that Astro knows which tag grouping the result is for.
  return allTags.flatMap((tag) => {
    const filteredPosts = allPosts.filter((post) => post.frontmatter.tag === tag);
    return paginate(filteredPosts, {
      params: { tag },
      pageSize: 10
    });
  });
}

const { page } = Astro.props;
const params = Astro.params;

Excluding pages

You can exclude pages or directories within src/pages from being built by prefixing their names with an underscore (_). Files with the _ prefix won’t be recognized by the router and won’t be placed into the dist/ directory.

You can use this to temporarily disable pages, and also to put tests, utilities, and components in the same folder as their related pages.

In this example, only src/pages/index.astro and src/pages/projects/project1.md will be built as page routes and HTML files.

• ディレクトリsrc/pages/

  • ディレクトリ_hidden-directory/

    • page1.md
    • page2.md
  • _hidden-page.astro
  • index.astro
  • ディレクトリprojects/

    • _SomeComponent.astro
    • _utils.js
    • project1.md

Advanced routing

追加： astro@7.0.0 ベータ

By default, Astro handles every request with a built-in pipeline that runs the handlers in a fixed order: trailing-slash normalization, redirects, sessions, actions, user middleware, page rendering, i18n, and caching. This pipeline is designed to cover the most common use cases for routing and request handling, but it may not fit every project’s needs.

Astro’s advanced routing allows you to replace this pipeline with your own. You can choose which built-in features to use and where to use them. You can also add your own custom logic anywhere in the pipeline. This gives you full control over how Astro handles incoming requests.

Creating a custom entrypoint

When the default pipeline does not fit your needs, you can override it by creating a src/fetch.ts file that default-exports an object with a fetch() method. This method receives a standard Request and must return a Response.

src/fetch.ts

import type { Fetchable } from 'astro';

export default {
  async fetch(request) {
    // Your custom request handling logic here
    return new Response("Hello from advanced routing!");
  }
} satisfies Fetchable;

Astro supports several file formats for its advanced routing entrypoint: .ts, .js, .mjs, and .mts. We recommend using .js in most cases or .ts if you need TypeScript support.

Changing the entrypoint filename

By default, Astro looks for src/fetch.ts as the advanced routing entrypoint. You can change this by setting the fetchFile option in your Astro config file.

The following example tells Astro to look for src/handler.ts instead of src/fetch.ts:

astro.config.mjs

export default defineConfig({
  fetchFile: 'handler',
});

Set fetchFile to null to disable the entrypoint entirely. This is useful if you already have a src/fetch.ts file used for other purposes:

astro.config.mjs

export default defineConfig({
  experimental: {
    advancedRouting: {
      fetchFile: null,
    },
  },
});

Adding custom logic

The main benefit of advanced routing is the ability to insert custom logic into the request pipeline. You can run code before Astro touches the request, between pipeline stages, or after the response is produced.

You can do this in two ways:

• Use the astro() handler to run the full built-in pipeline, and add logic before or after it.
• Compose individual handlers from astro/fetch or astro/hono for more control over execution order.

Running the full pipeline with astro()

Use astro() when you want to keep Astro’s built-in routing behavior, but need custom logic around it. This approach preserves the default pipeline order and lets you add pre-processing and post-processing in one place. For many use cases, such as adding auth guards, request logging, and custom headers, astro() is all you need.

The following example checks if a user can access a dashboard before running the Astro pipeline, and adds a custom header to the response once Astro has finished running:

src/fetch.ts

import { FetchState, astro } from 'astro/fetch';

export default {
  async fetch(request: Request): Promise<Response> {
    const state = new FetchState(request);

    // Custom pre-processing, runs before any Astro handler
    const url = new URL(request.url);
    if (url.pathname.startsWith('/dashboard')) {
      const cookie = request.headers.get('cookie') ?? '';
      if (!cookie.includes('session=')) {
        return new Response(null, {
          status: 302,
          headers: { Location: '/login' },
        });
      }
    }

    const response = await astro(state);

    // Custom post-processing, runs after Astro renders
    response.headers.set('X-Powered-By', 'Astro');
    return response;
  },
};

Composing individual handlers

When you need more control over the pipeline execution order, or want to omit certain features, you can compose individual handler functions from astro/fetch. Each handler operates on a FetchState object that tracks per-request data, such as the matched route, cookies, and session. You can call handlers in any order and insert custom logic between stages.

The following example runs only the handlers used in the project and adds custom logic after actions and before page rendering:

src/fetch.ts

import {
  FetchState,
  actions,
  middleware,
  pages,
  i18n,
} from 'astro/fetch';

export default {
  async fetch(request: Request): Promise<Response> {
    const state = new FetchState(request);

    const actionResponse = await actions(state);
    if (actionResponse) return actionResponse;

    // Custom logic between actions and page rendering
    console.log(`Rendering ${new URL(request.url).pathname}`);

    const response = await middleware(state, (s) => pages(s));
    return i18n(state, response);
  },
};

Using with Hono

Astro also provides Hono-compatible wrappers for all handler functions via astro/hono. If you prefer to use Hono as your routing framework, you can export a Hono app from src/fetch.ts:

src/fetch.ts

import { Hono } from 'hono';
import { logger } from 'hono/logger';
import { actions, middleware, pages, i18n } from 'astro/hono';

const app = new Hono();

// Hono middleware
app.use(logger());

// Astro handlers (as Hono middleware)
app.use(actions());
app.use(middleware());
app.use(pages());
app.use(i18n());

export default app;