diff --git a/core/main/client/browser.js b/core/main/client/browser.js
index a82d3df43..736b5f7b5 100644
--- a/core/main/client/browser.js
+++ b/core/main/client/browser.js
@@ -236,12 +236,20 @@ beef.browser = {
 		return !!window.devicePixelRatio && !!window.history.replaceState && typeof navigator.mozGetUserMedia != "undefined" && window.navigator.userAgent.match(/Firefox\/20\./) != null;
 	},
 
+    /**
+     * Returns true if FF21
+     * @example: beef.browser.isFF21()
+     */
+    isFF21:function () {
+        return !!window.devicePixelRatio && !!window.history.replaceState && typeof navigator.mozGetUserMedia != "undefined" && window.navigator.userAgent.match(/Firefox\/21\./) != null;
+    },
+
     /**
      * Returns true if FF.
      * @example: beef.browser.isFF()
      */
     isFF:function () {
-        return this.isFF2() || this.isFF3() || this.isFF3_5() || this.isFF3_6() || this.isFF4() || this.isFF5() || this.isFF6() || this.isFF7() || this.isFF8() || this.isFF9() || this.isFF10() || this.isFF11() || this.isFF12() || this.isFF13() || this.isFF14() || this.isFF15() || this.isFF16() || this.isFF17() || this.isFF18() || this.isFF19() || this.isFF20();
+        return this.isFF2() || this.isFF3() || this.isFF3_5() || this.isFF3_6() || this.isFF4() || this.isFF5() || this.isFF6() || this.isFF7() || this.isFF8() || this.isFF9() || this.isFF10() || this.isFF11() || this.isFF12() || this.isFF13() || this.isFF14() || this.isFF15() || this.isFF16() || this.isFF17() || this.isFF18() || this.isFF19() || this.isFF20() || this.isFF21();
     },
 
     /**
@@ -561,7 +569,8 @@ beef.browser = {
             FF17:this.isFF17(), // Firefox 17
             FF18:this.isFF18(), // Firefox 18
             FF19:this.isFF19(), // Firefox 19
-			FF20:this.isFF20(), // Firefox 20
+            FF20:this.isFF20(), // Firefox 20
+            FF21:this.isFF21(), // Firefox 21
             FF:this.isFF(), // Firefox any version
 
             IE6:this.isIE6(), // Internet Explorer 6
@@ -761,10 +770,14 @@ beef.browser = {
             return '19'
         }
         ;    // Firefox 19
-		if (this.isFF20()) {
-			return '20'
-		}
-		;	// Firefox 20
+        if (this.isFF20()) {
+            return '20'
+        }
+        ;    // Firefox 20
+        if (this.isFF21()) {
+            return '21'
+        }
+        ;    // Firefox 21
 
         if (this.isIE6()) {
             return '6'