next.js/docs/01-app/01-getting-started/02-project-structure.mdx

---
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.

<Image
  alt="Route segments to path segments"
  srcLight="/docs/light/top-level-folders.png"
  srcDark="/docs/dark/top-level-folders.png"
  width="1600"
  height="525"
/>

|                                                                    |                                    |
| ------------------------------------------------------------------ | ---------------------------------- |
| [`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       |

<AppOnly>

### 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 |

</AppOnly>

<PagesOnly>

### 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 |

</PagesOnly>

<AppOnly>

## 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`

<Image
  alt="Component Hierarchy for File Conventions"
  srcLight="/docs/light/file-conventions-component-hierarchy.png"
  srcDark="/docs/dark/file-conventions-component-hierarchy.png"
  width="1600"
  height="643"
/>

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.

<Image
  alt="Nested File Conventions Component Hierarchy"
  srcLight="/docs/light/nested-file-conventions-component-hierarchy.png"
  srcDark="/docs/dark/nested-file-conventions-component-hierarchy.png"
  width="1600"
  height="863"
/>

### 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.

<Image
  alt="A diagram showing how a route is not publicly accessible until a page.js or route.js file is added to a route segment."
  srcLight="/docs/light/project-organization-not-routable.png"
  srcDark="/docs/dark/project-organization-not-routable.png"
  width="1600"
  height="444"
/>

And, even when a route is made publicly accessible, only the **content returned** by `page.js` or `route.js` is sent to the client.

<Image
  alt="A diagram showing how page.js and route.js files make routes publicly accessible."
  srcLight="/docs/light/project-organization-routable.png"
  srcDark="/docs/dark/project-organization-routable.png"
  width="1600"
  height="687"
/>

This means that **project files** can be **safely colocated** inside route segments in the `app` directory without accidentally being routable.

<Image
  alt="A diagram showing colocated project files are not routable even when a segment contains a page.js or route.js file."
  srcLight="/docs/light/project-organization-colocation.png"
  srcDark="/docs/dark/project-organization-colocation.png"
  width="1600"
  height="1011"
/>

> **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.

<Image
  alt="An example folder structure using private folders"
  srcLight="/docs/light/project-organization-private-folders.png"
  srcDark="/docs/dark/project-organization-private-folders.png"
  width="1600"
  height="849"
/>

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.

<Image
  alt="An example folder structure using route groups"
  srcLight="/docs/light/project-organization-route-groups.png"
  srcDark="/docs/dark/project-organization-route-groups.png"
  width="1600"
  height="849"
/>

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.

<Image
  alt="An example folder structure with the `src` folder"
  srcLight="/docs/light/project-organization-src-directory.png"
  srcDark="/docs/dark/project-organization-src-directory.png"
  width="1600"
  height="687"
/>

## 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.

<Image
  alt="An example folder structure with project files outside of app"
  srcLight="/docs/light/project-organization-project-root.png"
  srcDark="/docs/dark/project-organization-project-root.png"
  width="1600"
  height="849"
/>

### 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**.

<Image
  alt="An example folder structure with project files inside app"
  srcLight="/docs/light/project-organization-app-root.png"
  srcDark="/docs/dark/project-organization-app-root.png"
  width="1600"
  height="849"
/>

### 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.

<Image
  alt="An example folder structure with project files split by feature or route"
  srcLight="/docs/light/project-organization-app-root-split.png"
  srcDark="/docs/dark/project-organization-app-root-split.png"
  width="1600"
  height="1011"
/>

### 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)`).

<Image
  alt="Organizing Routes with Route Groups"
  srcLight="/docs/light/route-group-organisation.png"
  srcDark="/docs/dark/route-group-organisation.png"
  width="1600"
  height="930"
/>

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.

<Image
  alt="Route Groups with Multiple Layouts"
  srcLight="/docs/light/route-group-multiple-layouts.png"
  srcDark="/docs/dark/route-group-multiple-layouts.png"
  width="1600"
  height="768"
/>

### 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`).

<Image
  alt="Route Groups with Opt-in Layouts"
  srcLight="/docs/light/route-group-opt-in-layouts.png"
  srcDark="/docs/dark/route-group-opt-in-layouts.png"
  width="1600"
  height="930"
/>

### 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.

<Image
  alt="Folder structure showing a loading.tsx and a page.tsx inside the route group"
  srcLight="/docs/light/route-group-loading.png"
  srcDark="/docs/dark/route-group-loading.png"
  width="1600"
  height="444"
/>

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 `<html>` and `<body>` tags need to be added to each root layout.

<Image
  alt="Route Groups with Multiple Root Layouts"
  srcLight="/docs/light/route-group-multiple-root-layouts.png"
  srcDark="/docs/dark/route-group-multiple-root-layouts.png"
  width="1600"
  height="687"
/>

In the example above, both `(marketing)` and `(shop)` have their own root layout.

</AppOnly>