---
title: Project structure and organization
nav_title: Project Structure
description: Learn the folder and file conventions in Next.js, and how to organize your project.
---
This page provides an overview of **all** the folder and file conventions in Next.js, and recommendations for organizing your project.
## Folder and file conventions
### Top-level folders
Top-level folders are used to organize your application's code and static assets.
| | |
| ------------------------------------------------------------------ | ---------------------------------- |
| [`app`](/docs/app) | App Router |
| [`pages`](/docs/pages/building-your-application/routing) | Pages Router |
| [`public`](/docs/app/api-reference/file-conventions/public-folder) | Static assets to be served |
| [`src`](/docs/app/api-reference/file-conventions/src-folder) | Optional application source folder |
### Top-level files
Top-level files are used to configure your application, manage dependencies, run middleware, integrate monitoring tools, and define environment variables.
| | |
| ---------------------------------------------------------------------------- | --------------------------------------- |
| **Next.js** | |
| [`next.config.js`](/docs/app/api-reference/config/next-config-js) | Configuration file for Next.js |
| [`package.json`](/docs/app/getting-started/installation#manual-installation) | Project dependencies and scripts |
| [`instrumentation.ts`](/docs/app/guides/instrumentation) | OpenTelemetry and Instrumentation file |
| [`middleware.ts`](/docs/app/api-reference/file-conventions/middleware) | Next.js request middleware |
| [`.env`](/docs/app/guides/environment-variables) | Environment variables |
| [`.env.local`](/docs/app/guides/environment-variables) | Local environment variables |
| [`.env.production`](/docs/app/guides/environment-variables) | Production environment variables |
| [`.env.development`](/docs/app/guides/environment-variables) | Development environment variables |
| [`.eslintrc.json`](/docs/app/api-reference/config/eslint) | Configuration file for ESLint |
| `.gitignore` | Git files and folders to ignore |
| `next-env.d.ts` | TypeScript declaration file for Next.js |
| `tsconfig.json` | Configuration file for TypeScript |
| `jsconfig.json` | Configuration file for JavaScript |
### Routing Files
| | | |
| ----------------------------------------------------------------------------- | ------------------- | ---------------------------- |
| [`layout`](/docs/app/api-reference/file-conventions/layout) | `.js` `.jsx` `.tsx` | Layout |
| [`page`](/docs/app/api-reference/file-conventions/page) | `.js` `.jsx` `.tsx` | Page |
| [`loading`](/docs/app/api-reference/file-conventions/loading) | `.js` `.jsx` `.tsx` | Loading UI |
| [`not-found`](/docs/app/api-reference/file-conventions/not-found) | `.js` `.jsx` `.tsx` | Not found UI |
| [`error`](/docs/app/api-reference/file-conventions/error) | `.js` `.jsx` `.tsx` | Error UI |
| [`global-error`](/docs/app/api-reference/file-conventions/error#global-error) | `.js` `.jsx` `.tsx` | Global error UI |
| [`route`](/docs/app/api-reference/file-conventions/route) | `.js` `.ts` | API endpoint |
| [`template`](/docs/app/api-reference/file-conventions/template) | `.js` `.jsx` `.tsx` | Re-rendered layout |
| [`default`](/docs/app/api-reference/file-conventions/default) | `.js` `.jsx` `.tsx` | Parallel route fallback page |
### Nested routes
| | |
| --------------- | -------------------- |
| `folder` | Route segment |
| `folder/folder` | Nested route segment |
### Dynamic routes
| | |
| ------------------------------------------------------------------------------------------------------ | -------------------------------- |
| [`[folder]`](/docs/app/api-reference/file-conventions/dynamic-routes#convention) | Dynamic route segment |
| [`[...folder]`](/docs/app/api-reference/file-conventions/dynamic-routes#catch-all-segments) | Catch-all route segment |
| [`[[...folder]]`](/docs/app/api-reference/file-conventions/dynamic-routes#optional-catch-all-segments) | Optional catch-all route segment |
### Route Groups and private folders
| | |
| ------------------------------------------------------------------------------ | ------------------------------------------------ |
| [`(folder)`](/docs/app/api-reference/file-conventions/route-groups#convention) | Group routes without affecting routing |
| [`_folder`](#private-folders) | Opt folder and all child segments out of routing |
### Parallel and Intercepted Routes
| | |
| ------------------------------------------------------------------------------------------- | -------------------------- |
| [`@folder`](/docs/app/api-reference/file-conventions/parallel-routes#slots) | Named slot |
| [`(.)folder`](/docs/app/api-reference/file-conventions/intercepting-routes#convention) | Intercept same level |
| [`(..)folder`](/docs/app/api-reference/file-conventions/intercepting-routes#convention) | Intercept one level above |
| [`(..)(..)folder`](/docs/app/api-reference/file-conventions/intercepting-routes#convention) | Intercept two levels above |
| [`(...)folder`](/docs/app/api-reference/file-conventions/intercepting-routes#convention) | Intercept from root |
### Metadata file conventions
#### App icons
| | | |
| --------------------------------------------------------------------------------------------------------------- | ----------------------------------- | ------------------------ |
| [`favicon`](/docs/app/api-reference/file-conventions/metadata/app-icons#favicon) | `.ico` | Favicon file |
| [`icon`](/docs/app/api-reference/file-conventions/metadata/app-icons#icon) | `.ico` `.jpg` `.jpeg` `.png` `.svg` | App Icon file |
| [`icon`](/docs/app/api-reference/file-conventions/metadata/app-icons#generate-icons-using-code-js-ts-tsx) | `.js` `.ts` `.tsx` | Generated App Icon |
| [`apple-icon`](/docs/app/api-reference/file-conventions/metadata/app-icons#apple-icon) | `.jpg` `.jpeg`, `.png` | Apple App Icon file |
| [`apple-icon`](/docs/app/api-reference/file-conventions/metadata/app-icons#generate-icons-using-code-js-ts-tsx) | `.js` `.ts` `.tsx` | Generated Apple App Icon |
#### Open Graph and Twitter images
| | | |
| --------------------------------------------------------------------------------------------------------------------------- | ---------------------------- | -------------------------- |
| [`opengraph-image`](/docs/app/api-reference/file-conventions/metadata/opengraph-image#opengraph-image) | `.jpg` `.jpeg` `.png` `.gif` | Open Graph image file |
| [`opengraph-image`](/docs/app/api-reference/file-conventions/metadata/opengraph-image#generate-images-using-code-js-ts-tsx) | `.js` `.ts` `.tsx` | Generated Open Graph image |
| [`twitter-image`](/docs/app/api-reference/file-conventions/metadata/opengraph-image#twitter-image) | `.jpg` `.jpeg` `.png` `.gif` | Twitter image file |
| [`twitter-image`](/docs/app/api-reference/file-conventions/metadata/opengraph-image#generate-images-using-code-js-ts-tsx) | `.js` `.ts` `.tsx` | Generated Twitter image |
#### SEO
| | | |
| ------------------------------------------------------------------------------------------------------------ | ----------- | --------------------- |
| [`sitemap`](/docs/app/api-reference/file-conventions/metadata/sitemap#sitemap-files-xml) | `.xml` | Sitemap file |
| [`sitemap`](/docs/app/api-reference/file-conventions/metadata/sitemap#generating-a-sitemap-using-code-js-ts) | `.js` `.ts` | Generated Sitemap |
| [`robots`](/docs/app/api-reference/file-conventions/metadata/robots#static-robotstxt) | `.txt` | Robots file |
| [`robots`](/docs/app/api-reference/file-conventions/metadata/robots#generate-a-robots-file) | `.js` `.ts` | Generated Robots file |
### Files conventions
| | | |
| ----------------------------------------------------------------------------------------------------------- | ------------------- | ----------------- |
| [`_app`](/docs/pages/building-your-application/routing/custom-app) | `.js` `.jsx` `.tsx` | Custom App |
| [`_document`](/docs/pages/building-your-application/routing/custom-document) | `.js` `.jsx` `.tsx` | Custom Document |
| [`_error`](/docs/pages/building-your-application/routing/custom-error#more-advanced-error-page-customizing) | `.js` `.jsx` `.tsx` | Custom Error Page |
| [`404`](/docs/pages/building-your-application/routing/custom-error#404-page) | `.js` `.jsx` `.tsx` | 404 Error Page |
| [`500`](/docs/pages/building-your-application/routing/custom-error#500-page) | `.js` `.jsx` `.tsx` | 500 Error Page |
### Routes
| | | |
| ---------------------------------------------------------------------------------------------- | ------------------- | ----------- |
| **Folder convention** | | |
| [`index`](/docs/pages/building-your-application/routing/pages-and-layouts#index-routes) | `.js` `.jsx` `.tsx` | Home page |
| [`folder/index`](/docs/pages/building-your-application/routing/pages-and-layouts#index-routes) | `.js` `.jsx` `.tsx` | Nested page |
| **File convention** | | |
| [`index`](/docs/pages/building-your-application/routing/pages-and-layouts#index-routes) | `.js` `.jsx` `.tsx` | Home page |
| [`file`](/docs/pages/building-your-application/routing/pages-and-layouts) | `.js` `.jsx` `.tsx` | Nested page |
### Dynamic routes
| | | |
| ----------------------------------------------------------------------------------------------------------------- | ------------------- | -------------------------------- |
| **Folder convention** | | |
| [`[folder]/index`](/docs/pages/building-your-application/routing/dynamic-routes) | `.js` `.jsx` `.tsx` | Dynamic route segment |
| [`[...folder]/index`](/docs/pages/building-your-application/routing/dynamic-routes#catch-all-segments) | `.js` `.jsx` `.tsx` | Catch-all route segment |
| [`[[...folder]]/index`](/docs/pages/building-your-application/routing/dynamic-routes#optional-catch-all-segments) | `.js` `.jsx` `.tsx` | Optional catch-all route segment |
| **File convention** | | |
| [`[file]`](/docs/pages/building-your-application/routing/dynamic-routes) | `.js` `.jsx` `.tsx` | Dynamic route segment |
| [`[...file]`](/docs/pages/building-your-application/routing/dynamic-routes#catch-all-segments) | `.js` `.jsx` `.tsx` | Catch-all route segment |
| [`[[...file]]`](/docs/pages/building-your-application/routing/dynamic-routes#optional-catch-all-segments) | `.js` `.jsx` `.tsx` | Optional catch-all route segment |
## Organizing your project
Next.js is **unopinionated** about how you organize and colocate your project files. But it does provide several features to help you organize your project.
### Component hierarchy
The components defined in special files are rendered in a specific hierarchy:
- `layout.js`
- `template.js`
- `error.js` (React error boundary)
- `loading.js` (React suspense boundary)
- `not-found.js` (React error boundary)
- `page.js` or nested `layout.js`
The components are rendered recursively in nested routes, meaning the components of a route segment will be nested **inside** the components of its parent segment.
### Colocation
In the `app` directory, nested folders define route structure. Each folder represents a route segment that is mapped to a corresponding segment in a URL path.
However, even though route structure is defined through folders, a route is **not publicly accessible** until a `page.js` or `route.js` file is added to a route segment.
And, even when a route is made publicly accessible, only the **content returned** by `page.js` or `route.js` is sent to the client.
This means that **project files** can be **safely colocated** inside route segments in the `app` directory without accidentally being routable.
> **Good to know**: While you **can** colocate your project files in `app` you don't **have** to. If you prefer, you can [keep them outside the `app` directory](#store-project-files-outside-of-app).
### Private folders
Private folders can be created by prefixing a folder with an underscore: `_folderName`
This indicates the folder is a private implementation detail and should not be considered by the routing system, thereby **opting the folder and all its subfolders** out of routing.
Since files in the `app` directory can be [safely colocated by default](#colocation), private folders are not required for colocation. However, they can be useful for:
- Separating UI logic from routing logic.
- Consistently organizing internal files across a project and the Next.js ecosystem.
- Sorting and grouping files in code editors.
- Avoiding potential naming conflicts with future Next.js file conventions.
> **Good to know**:
>
> - While not a framework convention, you might also consider marking files outside private folders as "private" using the same underscore pattern.
> - You can create URL segments that start with an underscore by prefixing the folder name with `%5F` (the URL-encoded form of an underscore): `%5FfolderName`.
> - If you don't use private folders, it would be helpful to know Next.js [special file conventions](/docs/app/getting-started/project-structure#routing-files) to prevent unexpected naming conflicts.
### Route groups
Route groups can be created by wrapping a folder in parenthesis: `(folderName)`
This indicates the folder is for organizational purposes and should **not be included** in the route's URL path.
Route groups are useful for:
- Organizing routes by site section, intent, or team. e.g. marketing pages, admin pages, etc.
- Enabling nested layouts in the same route segment level:
- [Creating multiple nested layouts in the same segment, including multiple root layouts](#creating-multiple-root-layouts)
- [Adding a layout to a subset of routes in a common segment](#opting-specific-segments-into-a-layout)
### `src` folder
Next.js supports storing application code (including `app`) inside an optional [`src` folder](/docs/app/api-reference/file-conventions/src-folder). This separates application code from project configuration files which mostly live in the root of a project.
## Examples
The following section lists a very high-level overview of common strategies. The simplest takeaway is to choose a strategy that works for you and your team and be consistent across the project.
> **Good to know**: In our examples below, we're using `components` and `lib` folders as generalized placeholders, their naming has no special framework significance and your projects might use other folders like `ui`, `utils`, `hooks`, `styles`, etc.
### Store project files outside of `app`
This strategy stores all application code in shared folders in the **root of your project** and keeps the `app` directory purely for routing purposes.
### Store project files in top-level folders inside of `app`
This strategy stores all application code in shared folders in the **root of the `app` directory**.
### Split project files by feature or route
This strategy stores globally shared application code in the root `app` directory and **splits** more specific application code into the route segments that use them.
### Organize routes without affecting the URL path
To organize routes without affecting the URL, create a group to keep related routes together. The folders in parenthesis will be omitted from the URL (e.g. `(marketing)` or `(shop)`).
Even though routes inside `(marketing)` and `(shop)` share the same URL hierarchy, you can create a different layout for each group by adding a `layout.js` file inside their folders.
### Opting specific segments into a layout
To opt specific routes into a layout, create a new route group (e.g. `(shop)`) and move the routes that share the same layout into the group (e.g. `account` and `cart`). The routes outside of the group will not share the layout (e.g. `checkout`).
### Opting for loading skeletons on a specific route
To apply a [loading skeleton](/docs/app/api-reference/file-conventions/loading) via a `loading.js` file to a specific route, create a new route group (e.g., `/(overview)`) and then move your `loading.tsx` inside that route group.
Now, the `loading.tsx` file will only apply to your dashboard → overview page instead of all your dashboard pages without affecting the URL path structure.
### Creating multiple root layouts
To create multiple [root layouts](/docs/app/api-reference/file-conventions/layout#root-layout), remove the top-level `layout.js` file, and add a `layout.js` file inside each route group. This is useful for partitioning an application into sections that have a completely different UI or experience. The `` and `` tags need to be added to each root layout.
In the example above, both `(marketing)` and `(shop)` have their own root layout.