diff --git a/electrum/gui/qt/settings_dialog.py b/electrum/gui/qt/settings_dialog.py
index aadd04b71..99a3c6eda 100644
--- a/electrum/gui/qt/settings_dialog.py
+++ b/electrum/gui/qt/settings_dialog.py
@@ -24,7 +24,7 @@
 # SOFTWARE.
 
 import ast
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, Dict
 
 from PyQt6.QtCore import Qt
 from PyQt6.QtWidgets import (QComboBox,  QTabWidget, QDialog, QSpinBox,  QCheckBox, QLabel,
@@ -32,7 +32,7 @@ from PyQt6.QtWidgets import (QComboBox,  QTabWidget, QDialog, QSpinBox,  QCheckB
 
 from electrum.i18n import _, languages
 from electrum import util
-from electrum.util import base_units_list, event_listener
+from electrum.util import base_units_list, event_listener, is_valid_websocket_url
 
 from electrum.gui import messages
 
@@ -181,7 +181,16 @@ class SettingsDialog(QDialog, QtEventListener):
         self.nostr_relays_e = QLineEdit(nostr_relays)
 
         def on_nostr_edit():
-            self.config.NOSTR_RELAYS = str(self.nostr_relays_e.text())
+            relays: Dict[str, None] = dict()  # dicts keep insertion order
+            for url in self.nostr_relays_e.text().split(','):
+                url = url.strip()
+                if url and is_valid_websocket_url(url):
+                    relays[url] = None
+            if relays.keys():
+                self.config.NOSTR_RELAYS = ",".join(relays.keys())
+            else:  # if no valid relays are given, assign default relays from config
+                self.config.NOSTR_RELAYS = None
+            self.nostr_relays_e.setText(self.config.NOSTR_RELAYS)
         self.nostr_relays_e.editingFinished.connect(on_nostr_edit)
 
         msat_cb = checkbox_from_configvar(self.config.cv.BTC_AMOUNTS_PREC_POST_SAT)
diff --git a/electrum/util.py b/electrum/util.py
index 4f210d3ef..0af4a70ae 100644
--- a/electrum/util.py
+++ b/electrum/util.py
@@ -31,14 +31,13 @@ from typing import (NamedTuple, Union, TYPE_CHECKING, Tuple, Optional, Callable,
 from datetime import datetime, timezone, timedelta
 import decimal
 from decimal import Decimal
-import urllib
+from urllib.parse import urlparse
 import threading
 import hmac
 import hashlib
 import stat
 import locale
 import asyncio
-import urllib.request, urllib.parse, urllib.error
 import builtins
 import json
 import time
@@ -699,6 +698,27 @@ def is_valid_email(s):
     regexp = r"[^@]+@[^@]+\.[^@]+"
     return re.match(regexp, s) is not None
 
+def is_valid_websocket_url(url: str) -> bool:
+    """
+    uses this django url validation regex:
+    https://github.com/django/django/blob/2c6906a0c4673a7685817156576724aba13ad893/django/core/validators.py#L45C1-L52C43
+    Note: this is not perfect, urls and their parsing can get very complex (see recent django code).
+    however its sufficient for catching weird user input in the gui dialog
+    """
+    # stores the compiled regex in the function object itself to avoid recompiling it every call
+    if not hasattr(is_valid_websocket_url, "regex"):
+        is_valid_websocket_url.regex = re.compile(
+            r'^(?:ws|wss)://'  # ws:// or wss://
+            r'(?:(?:[A-Z0-9](?:[A-Z0-9-]{0,61}[A-Z0-9])?\.)+(?:[A-Z]{2,6}\.?|[A-Z0-9-]{2,}\.?)|'  # domain...
+            r'localhost|'  # localhost...
+            r'\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}|'  # ...or ipv4
+            r'\[?[A-F0-9]*:[A-F0-9:]+\]?)'  # ...or ipv6
+            r'(?::\d+)?'  # optional port
+            r'(?:/?|[/?]\S+)$', re.IGNORECASE)
+    try:
+        return re.match(is_valid_websocket_url.regex, url) is not None
+    except Exception:
+        return False
 
 def is_hash256_str(text: Any) -> bool:
     if not isinstance(text, str): return False