Description:

By default wordpress upload do not support the “pdf” extention, applying this code to your function.php file, you’ll be able to upload, and manage pdf, as a normal multimedia file.

The Code:

function wpc_pdf_support( $post_mime_types ) {

	// select the mime type, here: 'application/pdf'
	// then we define an array with the label values

	$post_mime_types['application/pdf'] = array( __( 'PDFs' ), __( 'Manage PDFs' ), _n_noop( 'PDF <span class="count">(%s)</span>', 'PDFs <span class="count">(%s)</span>' ) );

	// then we return the $post_mime_types variable
	return $post_mime_types;

}

// Add Filter Hook
add_filter( 'post_mime_types', 'wpc_pdf_support' );