diff --git a/demos/blockfactory/app_controller.js b/demos/blockfactory/app_controller.js
index 5698033fe12..fcfa2296dcf 100644
--- a/demos/blockfactory/app_controller.js
+++ b/demos/blockfactory/app_controller.js
@@ -126,6 +126,16 @@ AppController.prototype.exportBlockLibraryToFile = function() {
   }
 };
 
+AppController.prototype.exportBlockLibraryAsJson = function() {
+  const blockJson = this.blockLibraryController.getBlockLibraryAsJson();
+  if (blockJson.length === 0) {
+    alert('No blocks in library to export');
+    return;
+  }
+  const filename = 'legacy_block_factory_export.txt';
+  FactoryUtils.createAndDownloadFile(JSON.stringify(blockJson), filename, 'plain');
+};
+
 /**
  * Converts an object mapping block type to XML to text file for output.
  * @param {!Object} blockXmlMap Object mapping block type to XML.
@@ -491,6 +501,10 @@ AppController.prototype.assignBlockFactoryClickHandlers = function() {
         self.exportBlockLibraryToFile();
       });
 
+  document.getElementById('exportAsJson').addEventListener('click', function() {
+    self.exportBlockLibraryAsJson();
+  });
+
   document.getElementById('helpButton').addEventListener('click',
       function() {
         open('https://developers.google.com/blockly/custom-blocks/block-factory',
diff --git a/demos/blockfactory/block_library_controller.js b/demos/blockfactory/block_library_controller.js
index 2192a7bdd11..7bb34e8d623 100644
--- a/demos/blockfactory/block_library_controller.js
+++ b/demos/blockfactory/block_library_controller.js
@@ -173,6 +173,29 @@ BlockLibraryController.prototype.getBlockLibrary = function() {
   return this.storage.getBlockXmlTextMap();
 };
 
+/**
+ * @return {Object[]} Array of JSON data, where each item is the data for one block type.
+ */
+BlockLibraryController.prototype.getBlockLibraryAsJson = function() {
+  const xmlBlocks = this.storage.getBlockXmlMap(this.storage.getBlockTypes());
+  const jsonBlocks = [];
+  const headlessWorkspace = new Blockly.Workspace();
+
+  for (const blockName in xmlBlocks) {
+    // Load the block XML into a workspace so we can save it as JSON
+    headlessWorkspace.clear();
+    const blockXml = xmlBlocks[blockName];
+    Blockly.Xml.domToWorkspace(blockXml, headlessWorkspace);
+    const block = headlessWorkspace.getBlocksByType('factory_base', false)[0];
+
+    if (!block) continue;
+
+    const json = Blockly.serialization.blocks.save(block, {addCoordinates: false, saveIds: false});
+    jsonBlocks.push(json);
+  }
+  return jsonBlocks;
+}
+
 /**
  * Return stored XML of a given block type.
  * @param {string} blockType The type of block.
diff --git a/demos/blockfactory/index.html b/demos/blockfactory/index.html
index 9f33aa4fbc4..c72efb7faf7 100644
--- a/demos/blockfactory/index.html
+++ b/demos/blockfactory/index.html
@@ -339,6 +339,9 @@ <h3>Preview:
               <button id="localSaveButton" title="Save block library XML to a local file.">
                 <span>Download Block Library</span>
               </button>
+              <button id="exportAsJson" title="Export block library for import into the new Block Factory.">
+                <span>Export Block Library</span>
+              </button>
             </td>
           </tr>
         </table>