unzip_file( string $file, string $to )

Unzips a specified ZIP file to a location on the Filesystem via the WordPress Filesystem Abstraction.

Description Description

Assumes that WP_Filesystem() has already been called and set up. Does not extract a root-level __MACOSX directory, if present.

Attempts to increase the PHP Memory limit to 256M before uncompressing, However, The most memory required shouldn’t be much larger than the Archive itself.

Parameters Parameters


(string) (Required) Full path and filename of zip archive


(string) (Required) Full path on the filesystem to extract archive to

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Return Return

(mixed) WP_Error on failure, True on success

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Source Source

File: wp-admin/includes/file.php

function unzip_file($file, $to) {
	global $wp_filesystem;

	if ( ! $wp_filesystem || !is_object($wp_filesystem) )
		return new WP_Error('fs_unavailable', __('Could not access filesystem.'));

	// Unzip can use a lot of memory, but not this much hopefully.
	wp_raise_memory_limit( 'admin' );

	$needed_dirs = array();
	$to = trailingslashit($to);

	// Determine any parent dir's needed (of the upgrade directory)
	if ( ! $wp_filesystem->is_dir($to) ) { //Only do parents if no children exist
		$path = preg_split('![/\\\]!', untrailingslashit($to));
		for ( $i = count($path); $i >= 0; $i-- ) {
			if ( empty($path[$i]) )

			$dir = implode('/', array_slice($path, 0, $i+1) );
			if ( preg_match('!^[a-z]:$!i', $dir) ) // Skip it if it looks like a Windows Drive letter.

			if ( ! $wp_filesystem->is_dir($dir) )
				$needed_dirs[] = $dir;
				break; // A folder exists, therefor, we dont need the check the levels below this

	 * Filters whether to use ZipArchive to unzip archives.
	 * @since 3.0.0
	 * @param bool $ziparchive Whether to use ZipArchive. Default true.
	if ( class_exists( 'ZipArchive', false ) && apply_filters( 'unzip_file_use_ziparchive', true ) ) {
		$result = _unzip_file_ziparchive($file, $to, $needed_dirs);
		if ( true === $result ) {
			return $result;
		} elseif ( is_wp_error($result) ) {
			if ( 'incompatible_archive' != $result->get_error_code() )
				return $result;
	// Fall through to PclZip if ZipArchive is not available, or encountered an error opening the file.
	return _unzip_file_pclzip($file, $to, $needed_dirs);

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Changelog Changelog

Version Description
2.5.0 Introduced.

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User Contributed Notes User Contributed Notes

  1. Skip to note 1 content
    Contributed by Codex


    Basic example showing how to unzip the contents of a .zip file, that resides in the WordPress upload directory, to the same destination.

    $destination = wp_upload_dir();
    $destination_path = $destination['path'];
    $unzipfile = unzip_file( $destination_path.'/filename.zip', $destination_path);
       if ( $unzipfile ) {
          echo 'Successfully unzipped the file!';       
       } else {
          echo 'There was an error unzipping the file.';       

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