diff --git a/src/lib/util.ts b/src/lib/util.ts
index 15d717fd..c09eb71c 100644
--- a/src/lib/util.ts
+++ b/src/lib/util.ts
@@ -113,6 +113,15 @@ let isInternalIP = (host: string): boolean => {
   );
 };
 
+let isValidURL = (url: string): boolean => {
+  try {
+    new URL(url);
+    return true; // The URL is valid
+  } catch (e) {
+    return false; // The URL is not valid
+  }
+};
+
 let isValidIP = (ip: string): boolean => {
   return /^(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/.test(
     ip
@@ -150,6 +159,7 @@ export default {
   ipToString,
   isInternalIP,
   isValidIP,
+  isValidURL,
   parseURL,
   validateIPRange,
 };
diff --git a/src/options/App.vue b/src/options/App.vue
index f60efd48..771283ce 100644
--- a/src/options/App.vue
+++ b/src/options/App.vue
@@ -459,7 +459,6 @@ enum Modal {
 
 @Component
 export default class App extends Vue {
-  public REGEX_DOMAIN: any = /^(?:^|\s)((https?:\/\/)?(?:localhost|[\w-]+(?:\.[\w-]+)+)(:\d+)?(\/\S*)?)/;
   public Modal = Modal;
   public modalType: Modal = Modal.DEFAULT;
   public currentTab: string = 'about';
@@ -964,7 +963,7 @@ export default class App extends Vue {
       }
 
       // test if valid domain
-      if (sites[i][0] === '' || !this.REGEX_DOMAIN.test(sites[i][0])) {
+      if (sites[i][0] === '' || !util.isValidURL(sites[i][0])) {
         this.errors.wlRuleSites = true;
         this.savingWLRule = false;