diff --git a/index.html b/index.html
index a54b7a77..5b62daac 100644
--- a/index.html
+++ b/index.html
@@ -204,19 +204,19 @@
             },
           },
           {
-            type: 'checklist',
+            type: 'List',
             data: {
               items: [
                 {
-                  text: "This is a block-styled editor",
+                  text: "This is Checklist tool data",
                   checked: true
                 },
                 {
-                  text: "Clean output data",
+                  text: "That would be displayed",
                   checked: false
                 },
                 {
-                  text: "Simple and powerful API",
+                  text: "In Nested List tool",
                   checked: true
                 }
               ]
diff --git a/src/types/ListParams.ts b/src/types/ListParams.ts
index 8461ca92..8d9fef5b 100644
--- a/src/types/ListParams.ts
+++ b/src/types/ListParams.ts
@@ -42,6 +42,30 @@ export interface OldListData {
   items: string[];
 }
 
+/**
+ * Interface that represents old checklist data format
+ */
+export interface OldChecklistData {
+  /**
+   * Checklist items
+   */
+  items: OldChecklistItem[];
+}
+
+/**
+ * Interface that represents old checklist item format
+ */
+interface OldChecklistItem {
+  /**
+   * Text of the checklist item
+   */
+  text: string;
+  /**
+   * Checked state of the checklist item
+   */
+  checked: boolean;
+}
+
 /**
  * List item within the output data
  */
diff --git a/src/utils/normalizeData.ts b/src/utils/normalizeData.ts
index 6299d8c1..51b2e0a1 100644
--- a/src/utils/normalizeData.ts
+++ b/src/utils/normalizeData.ts
@@ -1,23 +1,38 @@
-import type { OldListData, ListData, ListItem } from '../types/ListParams';
+import type { OldListData, ListData, ListItem, OldChecklistData } from '../types/ListParams';
 
 /**
- * Method that checks if data is related to the List or NestedListTool
- * @param data - data of the List or NestedListTool
- * @returns true if data related to the List tool, false if to Nested List tool
+ * Method that checks if data is result of the Old list tool save mtehod
+ * @param data - data of the OldList, Checklist or NestedList tool
+ * @returns true if data related to the List tool, false otherwise
  */
-function instanceOfListData(data: ListData | OldListData): data is OldListData {
+function instanceOfOldListData(data: ListData | OldListData | OldChecklistData): data is OldListData {
   return (typeof data.items[0] === 'string');
 }
 
+/**
+ * Method that checks if data is result of the Old checklist tool save method
+ * @param data - data of the Checklist, OldList or NestedList tool
+ * @returns true if data is related to the Checklist tool, false otherwise
+ */
+function instanceOfChecklistData(data: ListData | OldListData | OldChecklistData): data is OldChecklistData {
+  return (
+    typeof data.items[0] !== 'string'
+    && 'text' in data.items[0]
+    && 'checked' in data.items[0]
+    && typeof data.items[0].text === 'string'
+    && typeof data.items[0].checked === 'boolean'
+  );
+}
+
 /**
  * Method that checks if passed data is related to the legacy format and normalizes it
  * @param data - data to be checked
  * @returns - normalized data, ready to be used by Nested List tool
  */
-export default function normalizeData(data: ListData | OldListData): ListData {
+export default function normalizeData(data: ListData | OldListData | OldChecklistData): ListData {
   const normalizedDataItems: ListItem[] = [];
 
-  if (instanceOfListData(data)) {
+  if (instanceOfOldListData(data)) {
     data.items.forEach((item) => {
       normalizedDataItems.push({
         content: item,
@@ -30,6 +45,21 @@ export default function normalizeData(data: ListData | OldListData): ListData {
       style: data.style,
       items: normalizedDataItems,
     };
+  } else if (instanceOfChecklistData(data)) {
+    data.items.forEach((item) => {
+      normalizedDataItems.push({
+        content: item.text,
+        meta: {
+          checked: item.checked,
+        },
+        items: [],
+      });
+    });
+
+    return {
+      style: 'checklist',
+      items: normalizedDataItems,
+    };
   } else {
     return data;
   }