diff --git a/android/src/main/java/android/print/PdfConverter.java b/android/src/main/java/android/print/PdfConverter.java
index 36f7269..44d9a2f 100644
--- a/android/src/main/java/android/print/PdfConverter.java
+++ b/android/src/main/java/android/print/PdfConverter.java
@@ -45,22 +45,23 @@ public static synchronized PdfConverter getInstance() {
 
     @Override
     public void run() {
-        if (mContext == null || mHtmlString == null || mPdfFile == null) return;
-
         mWebView = new WebView(mContext);
         mWebView.setWebViewClient(new WebViewClient() {
             @Override
             public void onPageFinished(WebView view, String url) {
-                if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) return;
-
-                PrintDocumentAdapter documentAdapter = mWebView.createPrintDocumentAdapter();
-                documentAdapter.onLayout(null, getPdfPrintAttrs(), null, new PrintDocumentAdapter.LayoutResultCallback() {}, null);
-                documentAdapter.onWrite(new PageRange[]{PageRange.ALL_PAGES}, getOutputFileDescriptor(), null, new PrintDocumentAdapter.WriteResultCallback() {
-                    @Override
-                    public void onWriteFinished(PageRange[] pages) {
-                        destroy();
-                    }
-                });
+                if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT)
+                    throw new RuntimeException("call requires API level 19");
+                else {
+                    PrintDocumentAdapter documentAdapter = mWebView.createPrintDocumentAdapter();
+                    documentAdapter.onLayout(null, getPdfPrintAttrs(), null, new PrintDocumentAdapter.LayoutResultCallback() {
+                    }, null);
+                    documentAdapter.onWrite(new PageRange[]{PageRange.ALL_PAGES}, getOutputFileDescriptor(), null, new PrintDocumentAdapter.WriteResultCallback() {
+                        @Override
+                        public void onWriteFinished(PageRange[] pages) {
+                            destroy();
+                        }
+                    });
+                }
             }
         });
         mWebView.loadData(mHtmlString, "text/HTML", "UTF-8");
@@ -75,6 +76,13 @@ public void setPdfPrintAttrs(PrintAttributes printAttrs) {
     }
 
     public void convert(Context context, String htmlString, File file) {
+        if (context == null)
+            throw new IllegalArgumentException("context can't be null");
+        if (htmlString == null)
+            throw new IllegalArgumentException("htmlString can't be null");
+        if (file == null)
+            throw new IllegalArgumentException("file can't be null");
+
         if (mIsCurrentlyConverting)
             return;
 
diff --git a/android/src/main/java/com/christopherdro/htmltopdf/RNHTMLtoPDFModule.java b/android/src/main/java/com/christopherdro/htmltopdf/RNHTMLtoPDFModule.java
index cde8847..3f9d877 100644
--- a/android/src/main/java/com/christopherdro/htmltopdf/RNHTMLtoPDFModule.java
+++ b/android/src/main/java/com/christopherdro/htmltopdf/RNHTMLtoPDFModule.java
@@ -11,6 +11,10 @@
 import java.io.File;
 import java.util.UUID;
 
+import android.util.Base64;
+import java.io.IOException;
+import java.io.RandomAccessFile;
+
 
 import android.os.Environment;
 import android.print.PdfConverter;
@@ -52,9 +56,16 @@ public void convert(final ReadableMap options, final Promise promise) {
       }
 
       String filePath = convertToPDF(htmlString, destinationFile);
+      String base64 = "";
+
+      if (options.hasKey("base64") && options.getBoolean("base64") == true) {
+        base64 = encodeFromFile(destinationFile);
+      }
+
 
       WritableMap resultMap = Arguments.createMap();
       resultMap.putString("filePath", filePath);
+      resultMap.putString("base64", base64);
 
       promise.resolve(resultMap);
     } catch (Exception e) {
@@ -86,4 +97,10 @@ private File getTempFile(String fileName) throws Exception {
     }
   }
 
+  private String encodeFromFile(File file) throws IOException{
+    RandomAccessFile randomAccessFile = new RandomAccessFile(file, "r");
+    byte[] fileBytes = new byte[(int)randomAccessFile.length()];
+    randomAccessFile.readFully(fileBytes);
+    return Base64.encodeToString(fileBytes, Base64.DEFAULT);
+  }
 }