---
title: "Efficiently serving large static files (X-Sendfile/X-Accel-Redirect)"
description: "Configure FrankenPHP to delegate large static file delivery to the web server after running PHP code, using X-Sendfile or X-Accel-Redirect headers."
sidebar:
  label: "Efficiently serving large static files"
  order: 6
seo:
  title: "Serving large files with X-Sendfile and X-Accel-Redirect in FrankenPHP"
---
Usually, static files can be served directly by the web server,
but sometimes it's necessary to execute some PHP code before sending them:
access control, statistics, custom HTTP headers...

Unfortunately, using PHP to serve large static files is inefficient compared to
direct use of the web server (memory overload, reduced performance...).

FrankenPHP lets you delegate the sending of static files to the web server
**after** executing customized PHP code.

To do this, your PHP application simply needs to define a custom HTTP header
containing the path of the file to be served. FrankenPHP takes care of the rest.

This feature is known as **`X-Sendfile`** for Apache, and **`X-Accel-Redirect`** for NGINX.

In the following examples, we assume that the document root of the project is the `public/` directory,
and that we want to use PHP to serve files stored outside the `public/` directory,
from a directory named `private-files/`.

## Configuring X-Accel-Redirect in the FrankenPHP Caddyfile

First, add the following configuration to your `Caddyfile` to enable this feature:

```patch
	root public/
	# ...

+	# Needed for Symfony, Laravel and other projects using the Symfony HttpFoundation component
+	request_header X-Sendfile-Type x-accel-redirect
+	request_header X-Accel-Mapping ../private-files=/private-files
+
+	intercept {
+		@accel header X-Accel-Redirect *
+		handle_response @accel {
+			root private-files/
+			rewrite * {resp.header.X-Accel-Redirect}
+			method * GET
+
+			# Remove the X-Accel-Redirect header set by PHP for increased security
+			header -X-Accel-Redirect
+
+			file_server
+		}
+	}

	php_server
```

## Plain PHP

Set the relative file path (from `private-files/`) as the value of the `X-Accel-Redirect` header:

```php
header('X-Accel-Redirect: file.txt');
```

## Projects using the Symfony HttpFoundation component (Symfony, Laravel, Drupal...)

See [the Symfony documentation](/ru/docs/symfony#serving-large-static-files-x-sendfile) for details on using this feature with Symfony HttpFoundation.