Site config is where you can define the global settings of the site. App config options define settings that apply to every VitePress site, regardless of what theme it is using. For example, the base directory or the title of the site.
The config file is always resolved from `<root>/.vitepress/config.[ext]`, where `<root>` is your VitePress [project root](/guide/routing#root-and-source-directory), and `[ext]` is one of the supported file extensions. TypeScript is supported out of the box. Supported extensions include `.js`, `.ts`, `.cjs`, `.mjs`, `.cts`, and `.mts`.
Using the `defineConfig` helper will provide TypeScript-powered intellisense for config options. Assuming your IDE supports it, this should work in both JavaScript and TypeScript.
If you use a custom theme and want type checks for the theme config, you'll need to use `defineConfigWithTheme` instead, and pass the config type for your custom theme via a generic argument:
It will also be used as the default suffix for all individual page titles, unless [`titleTemplate`](#titletemplate) is defined. An individual page's final title will be the text content of its first `<h1>` header, combined with the global `title` as the suffix. For example with the following config and page content:
Here `:title` will be replaced with the text inferred from the page's first `<h1>` header. The title of the previous example page will be `Hello - Custom Suffix`.
The option can be set to `false` to disable title suffixes.
Additional elements to render in the `<head>` tag in the page HTML. The user-added tags are rendered before the closing `head` tag, after VitePress tags.
The base URL the site will be deployed at. You will need to set this if you plan to deploy your site under a sub path, for example, GitHub pages. If you plan to deploy your site to `https://foo.github.io/bar/`, then you should set base to `'/bar/'`. It should always start and end with a slash.
The base is automatically prepended to all the URLs that start with / in other options, so you only need to specify it once.
Enabling this may require additional configuration on your hosting platform. For it to work, your server must be able to serve `/foo.html` when visiting `/foo`**without a redirect**.
The directory where your markdown pages are stored, relative to project root. Also see [Root and Source Directory](/guide/routing#root-and-source-directory).
The build output location for the site, relative to [project root](/guide/routing#root-and-source-directory).
```ts
export default {
outDir: '../public'
}
```
### cacheDir
- Type: `string`
- Default: `./.vitepress/cache`
The directory for cache files, relative to [project root](/guide/routing#root-and-source-directory). See also: [cacheDir](https://vitejs.dev/config/shared-options.html#cachedir).
When set to `true`, VitePress will not fail builds due to dead links. When set to `'localhostLinks'`, the build will fail on dead links, but won't check `localhost` links.
When set to `true`, the production app will be built in [MAP Mode](/guide/mpa-mode). MPA mode ships 0kb JavaScript by default, at the cost of disabling client-side navigation and requires explicit opt-in for interactivity.
Whether to enable dark mode (by adding the `.dark` class to the `<html>` element).
- If the option is set to `true`, the default theme will be determined by the user's preferred color scheme.
- If the option is set to `dark`, the theme will be dark by default, unless the user manually toggles it.
- If the option is set to `false`, users will not be able to toggle the theme.
This option injects an inline script that restores users settings from local storage using the `vitepress-theme-appearance` key. This ensures the `.dark` class is applied before the page is rendered to avoid flickering.
### lastUpdated
- Type: `boolean`
- Default: `false`
Whether to get the last updated timestamp for each page using Git. The timestamp will be included in each page's page data, accessible via [`useData`](/reference/runtime-api#usedata).
When using the default theme, enabling this option will display each page's last updated time. You can customize the text via [`themeConfig.lastUpdatedText`](./default-theme-config#lastupdatedtext) option.
Configure Markdown parser options. VitePress uses [Markdown-it](https://github.com/markdown-it/markdown-it) as the parser, and [Shiki](https://shiki.matsu.io/) to highlight language syntax. Inside this option, you may pass various Markdown related options to fit your needs.
Pass raw [`@vitejs/plugin-vue` options](https://github.com/vitejs/vite-plugin-vue/tree/main/packages/plugin-vue#options) to the internal plugin instance.
`transformHead` is a build hook to transform the head before generating each page. It will allow you to add head entries that cannot be statically added to your VitePress config. You only need to return extra entries, they will be merged automatically with the existing ones.
`transformPageData` is a hook to transform the `pageData` of each page. You can directly mutate `pageData` or return changed values which will be merged into PageData.
