diff --git a/src/ZugferdDocumentPdfBuilder.php b/src/ZugferdDocumentPdfBuilder.php
index 2f1945d..67214b7 100644
--- a/src/ZugferdDocumentPdfBuilder.php
+++ b/src/ZugferdDocumentPdfBuilder.php
@@ -91,6 +91,17 @@ public function saveDocument(string $toFilename): ZugferdDocumentPdfBuilder
 
         return $this;
     }
+    
+    /**
+     * Returns the PDF as a string
+     *
+     * @param  string $toFilename
+     * @return string
+     */
+    public function downloadString(string $toFilename): string
+    {
+        return $this->pdfWriter->Output($toFilename, 'S');
+    }
 
     /**
      * Internal function which sets up the PDF
diff --git a/tests/testcases/PdfBuilderEn16931Test.php b/tests/testcases/PdfBuilderEn16931Test.php
index e83e626..bd4ef6b 100644
--- a/tests/testcases/PdfBuilderEn16931Test.php
+++ b/tests/testcases/PdfBuilderEn16931Test.php
@@ -91,6 +91,15 @@ public function testBuildPdf(): void
         $this->assertTrue(file_exists(self::$destPdfFilename));
     }
 
+    public function testBuildPdfString(): void
+    {
+        $pdfBuilder = new ZugferdDocumentPdfBuilder(self::$document, self::$sourcePdfFilename);
+        $pdfBuilder->generateDocument();
+        $pdfBuilder->downloadString(self::$destPdfFilename);
+
+        $this->assertIsString(self::$destPdfFilename);
+    }
+
     public function testPdfMetaData(): void
     {
         $pdfParser = new PdfParser();