diff --git a/doc/UTIL_API.md b/doc/UTIL_API.md
index 57b7c29..2dc411e 100644
--- a/doc/UTIL_API.md
+++ b/doc/UTIL_API.md
@@ -1740,6 +1740,19 @@ loadJs('main.js', function (isLoaded) {
 });
 ```
 
+## lowerCase 
+
+Convert string to lower case.
+
+|Name  |Type  |Desc              |
+|------|------|------------------|
+|str   |string|String to convert |
+|return|string|Lower cased string|
+
+```javascript
+lowerCase('TEST'); // -> 'test'
+```
+
 ## lpad 
 
 Pad string on the left side if it's shorter than length.
diff --git a/src/lib/JsonViewer.js b/src/lib/JsonViewer.js
index db8fe92..a3a5e5b 100644
--- a/src/lib/JsonViewer.js
+++ b/src/lib/JsonViewer.js
@@ -15,7 +15,8 @@ import {
   isNum,
   isBool,
   keys,
-  trim
+  trim,
+  lowerCase
 } from './util'
 
 export default class JsonViewer {
@@ -83,11 +84,15 @@ export default class JsonViewer {
 
     if (val === null) {
       return `<li>${wrapKey(key)}<span class="eruda-null">null</span></li>`
-    } else if (type === 'Number' || isNum(val) || isBool(val)) {
+    } else if (val.type === 'Number' || isNum(val) || isBool(val)) {
       return `<li>${wrapKey(key)}<span class="eruda-${typeof val}">${encode(
         val
       )}</span></li>`
-    } else if (type === 'Undefined' || val === 'Symbol' || val === '(...)') {
+    } else if (val.type === 'Undefined' || val.type === 'Symbol') {
+      return `<li>${wrapKey(key)}<span class="eruda-special">${lowerCase(
+        val.type
+      )}</span></li>`
+    } else if (val === '(...)') {
       return `<li>${wrapKey(key)}<span class="eruda-special">${val}</span></li>`
     } else if (isObj(val)) {
       id = val.id
diff --git a/src/lib/util.js b/src/lib/util.js
index 4507dfc..2b94f47 100644
--- a/src/lib/util.js
+++ b/src/lib/util.js
@@ -2734,6 +2734,36 @@ export var loadJs = _.loadJs = (function (exports) {
     return exports;
 })({});
 
+/* ------------------------------ lowerCase ------------------------------ */
+
+export var lowerCase = _.lowerCase = (function (exports) {
+    /* Convert string to lower case.
+     *
+     * |Name  |Type  |Desc              |
+     * |------|------|------------------|
+     * |str   |string|String to convert |
+     * |return|string|Lower cased string|
+     */
+
+    /* example
+     * lowerCase('TEST'); // -> 'test'
+     */
+
+    /* typescript
+     * export declare function lowerCase(str: string): string;
+     */
+
+    /* dependencies
+     * toStr 
+     */
+
+    exports = function exports(str) {
+        return toStr(str).toLocaleLowerCase();
+    };
+
+    return exports;
+})({});
+
 /* ------------------------------ repeat ------------------------------ */
 
 export var repeat = _.repeat = (function (exports) {