diff --git a/packages/ndk/lib/shared/helpers/relay_helper.dart b/packages/ndk/lib/shared/helpers/relay_helper.dart
index 85aa66454..8bc846fcb 100644
--- a/packages/ndk/lib/shared/helpers/relay_helper.dart
+++ b/packages/ndk/lib/shared/helpers/relay_helper.dart
@@ -1,15 +1,18 @@
 // ignore: public_member_api_docs, non_constant_identifier_names
 final RegExp RELAY_URL_REGEX = RegExp(
-    r'^(wss?:\/\/)([0-9]{1,3}(?:\.[0-9]{1,3}){3}|[^:]+):?([0-9]{1,5})?$');
+    r'^(wss?:\/\/)([a-zA-Z0-9]([a-zA-Z0-9\-]*[a-zA-Z0-9])?(\.[a-zA-Z0-9]([a-zA-Z0-9\-]*[a-zA-Z0-9])?)*|[0-9]{1,3}(?:\.[0-9]{1,3}){3}):?([0-9]{1,5})?(\/[^\s]*)?$');
 
 String? cleanRelayUrl(String adr) {
+  adr = adr.trim();
   if (adr.endsWith("/")) {
     adr = adr.substring(0, adr.length - 1);
   }
   if (adr.contains("%")) {
     adr = Uri.decodeComponent(adr);
   }
-  adr = adr.trim();
+  // Remove extra slashes after protocol (e.g., wss:/// -> wss://)
+  adr = adr.replaceFirstMapped(
+      RegExp(r'^(wss?:)\/{3,}'), (match) => '${match.group(1)}//');
   if (!adr.contains(RELAY_URL_REGEX)) {
     return null;
   }
diff --git a/packages/ndk/test/relays/trailing_slash_test.dart b/packages/ndk/test/relays/trailing_slash_test.dart
index a896584b4..c24600ba7 100644
--- a/packages/ndk/test/relays/trailing_slash_test.dart
+++ b/packages/ndk/test/relays/trailing_slash_test.dart
@@ -313,4 +313,21 @@ void main() {
       ndk.destroy();
     });
   });
+
+  group('Triple slash', () {
+    test('query triple slashes relays: wss:///', () async {
+      final ndk = Ndk.emptyBootstrapRelaysConfig();
+
+      final query = ndk.requests.query(
+        filters: [
+          Filter(kinds: [0]),
+        ],
+        explicitRelays: ["wss:///example.com"],
+      );
+
+      await query.future;
+
+      ndk.destroy();
+    });
+  });
 }
diff --git a/packages/ndk/test/shared/helpers/relay_helper_test.dart b/packages/ndk/test/shared/helpers/relay_helper_test.dart
new file mode 100644
index 000000000..97a3d64a7
--- /dev/null
+++ b/packages/ndk/test/shared/helpers/relay_helper_test.dart
@@ -0,0 +1,164 @@
+import 'package:ndk/shared/helpers/relay_helper.dart';
+import 'package:test/test.dart';
+
+void main() {
+  group('cleanRelayUrl', () {
+    group('valid URLs', () {
+      test('accepts valid wss URL with port + path', () {
+        expect(cleanRelayUrl('wss://relay.damus.io:5000/abc/aa.co.mm'), 'wss://relay.damus.io:5000/abc/aa.co.mm');
+      });
+
+      test('accepts valid wss URL', () {
+        expect(cleanRelayUrl('wss://relay.damus.io'), 'wss://relay.damus.io');
+      });
+
+      test('accepts valid ws URL', () {
+        expect(cleanRelayUrl('ws://localhost'), 'ws://localhost');
+      });
+
+      test('accepts URL with port', () {
+        expect(cleanRelayUrl('wss://relay.example.com:8080'),
+            'wss://relay.example.com:8080');
+      });
+
+      test('accepts URL with subdomain', () {
+        expect(cleanRelayUrl('wss://nostr.relay.example.com'),
+            'wss://nostr.relay.example.com');
+      });
+
+      test('accepts IP address', () {
+        expect(cleanRelayUrl('wss://192.168.1.1'), 'wss://192.168.1.1');
+      });
+
+      test('accepts IP address with port', () {
+        expect(
+            cleanRelayUrl('wss://192.168.1.1:8080'), 'wss://192.168.1.1:8080');
+      });
+
+      test('accepts localhost', () {
+        expect(cleanRelayUrl('ws://localhost'), 'ws://localhost');
+      });
+
+      test('accepts localhost with port', () {
+        expect(cleanRelayUrl('ws://localhost:7777'), 'ws://localhost:7777');
+      });
+    });
+
+    group('URL cleaning', () {
+      test('removes trailing slash', () {
+        expect(cleanRelayUrl('wss://relay.damus.io/'), 'wss://relay.damus.io');
+      });
+
+      test('trims whitespace', () {
+        expect(
+            cleanRelayUrl('  wss://relay.damus.io  '), 'wss://relay.damus.io');
+      });
+
+      test('decodes percent-encoded URL', () {
+        expect(cleanRelayUrl('wss://relay.example%2Ecom'),
+            'wss://relay.example.com');
+      });
+
+      test('fixes triple slash URL', () {
+        expect(cleanRelayUrl('wss:///relay.damus.io'), 'wss://relay.damus.io');
+      });
+
+      test('fixes multiple extra slashes', () {
+        expect(cleanRelayUrl('wss:////relay.damus.io'), 'wss://relay.damus.io');
+      });
+    });
+
+    group('invalid URLs', () {
+      test('returns null for empty string', () {
+        expect(cleanRelayUrl(''), null);
+      });
+
+      test('returns null for URL without protocol', () {
+        expect(cleanRelayUrl('relay.damus.io'), null);
+      });
+
+      test('returns null for http URL', () {
+        expect(cleanRelayUrl('http://relay.damus.io'), null);
+      });
+
+      test('returns null for https URL', () {
+        expect(cleanRelayUrl('https://relay.damus.io'), null);
+      });
+
+      test('returns null for URL with only protocol', () {
+        expect(cleanRelayUrl('wss://'), null);
+      });
+
+      test('returns null for triple slash with no host', () {
+        expect(cleanRelayUrl('wss:///'), null);
+      });
+
+      test('returns null for invalid characters in host', () {
+        expect(cleanRelayUrl('wss://relay space.com'), null);
+      });
+
+      test('returns null for host starting with hyphen', () {
+        expect(cleanRelayUrl('wss://-relay.com'), null);
+      });
+
+      test('returns null for host ending with hyphen', () {
+        expect(cleanRelayUrl('wss://relay-.com'), null);
+      });
+    });
+  });
+
+  group('cleanRelayUrls', () {
+    test('returns empty list for empty input', () {
+      expect(cleanRelayUrls([]), []);
+    });
+
+    test('filters out invalid URLs', () {
+      final urls = [
+        'wss://relay.damus.io',
+        'invalid-url',
+        'wss://nos.lol',
+      ];
+      expect(cleanRelayUrls(urls), ['wss://relay.damus.io', 'wss://nos.lol']);
+    });
+
+    test('cleans valid URLs', () {
+      final urls = [
+        'wss://relay.damus.io/',
+        '  wss://nos.lol  ',
+      ];
+      expect(cleanRelayUrls(urls), ['wss://relay.damus.io', 'wss://nos.lol']);
+    });
+
+    test('returns empty list when all URLs are invalid', () {
+      final urls = [
+        'invalid',
+        'http://example.com',
+        '',
+      ];
+      expect(cleanRelayUrls(urls), []);
+    });
+
+    test('fixes triple slash URLs in list', () {
+      final urls = [
+        'wss:///relay.damus.io',
+        'wss://nos.lol',
+      ];
+      expect(cleanRelayUrls(urls), ['wss://relay.damus.io', 'wss://nos.lol']);
+    });
+  });
+
+  group('RELAY_URL_REGEX', () {
+    test('matches valid relay URL pattern', () {
+      expect(RELAY_URL_REGEX.hasMatch('wss://relay.damus.io'), true);
+      expect(RELAY_URL_REGEX.hasMatch('ws://localhost'), true);
+      expect(RELAY_URL_REGEX.hasMatch('wss://192.168.1.1'), true);
+      expect(RELAY_URL_REGEX.hasMatch('wss://relay.example.com:8080'), true);
+    });
+
+    test('does not match invalid patterns', () {
+      expect(RELAY_URL_REGEX.hasMatch('http://example.com'), false);
+      expect(RELAY_URL_REGEX.hasMatch('wss://'), false);
+      expect(RELAY_URL_REGEX.hasMatch('wss:///example.com'), false);
+    });
+  });
+}