diff --git a/changedetectionio/templates/base.html b/changedetectionio/templates/base.html
index a9ea54460..e0e8bf058 100644
--- a/changedetectionio/templates/base.html
+++ b/changedetectionio/templates/base.html
@@ -1,5 +1,5 @@
-
+
diff --git a/changedetectionio/tests/test_i18n.py b/changedetectionio/tests/test_i18n.py
new file mode 100644
index 000000000..3a827957c
--- /dev/null
+++ b/changedetectionio/tests/test_i18n.py
@@ -0,0 +1,110 @@
+#!/usr/bin/env python3
+
+from flask import url_for
+from .util import live_server_setup
+
+
+def test_language_switching(client, live_server, measure_memory_usage, datastore_path):
+ """
+ Test that the language switching functionality works correctly.
+
+ 1. Switch to Italian using the /set-language endpoint
+ 2. Verify that Italian text appears on the page
+ 3. Switch back to English and verify English text appears
+ """
+
+ # Step 1: Set the language to Italian using the /set-language endpoint
+ res = client.get(
+ url_for("set_language", locale="it"),
+ follow_redirects=True
+ )
+
+ assert res.status_code == 200
+
+ # Step 2: Request the index page - should be in Italian
+ # The session cookie should be maintained by the test client
+ res = client.get(
+ url_for("watchlist.index"),
+ follow_redirects=True
+ )
+
+ assert res.status_code == 200
+
+ # Check for Italian text - "Annulla" (translation of "Cancel")
+ assert b"Annulla" in res.data, "Expected Italian text 'Annulla' not found after setting language to Italian"
+
+ # Step 3: Switch back to English
+ res = client.get(
+ url_for("set_language", locale="en"),
+ follow_redirects=True
+ )
+
+ assert res.status_code == 200
+
+ # Request the index page - should now be in English
+ res = client.get(
+ url_for("watchlist.index"),
+ follow_redirects=True
+ )
+
+ assert res.status_code == 200
+
+ # Check for English text
+ assert b"Cancel" in res.data, "Expected English text 'Cancel' not found after switching back to English"
+
+
+def test_invalid_locale(client, live_server, measure_memory_usage, datastore_path):
+ """
+ Test that setting an invalid locale doesn't break the application.
+ The app should ignore invalid locales and continue working.
+ """
+
+ # First set to English
+ res = client.get(
+ url_for("set_language", locale="en"),
+ follow_redirects=True
+ )
+
+ assert res.status_code == 200
+
+ # Try to set an invalid locale
+ res = client.get(
+ url_for("set_language", locale="invalid_locale_xyz"),
+ follow_redirects=True
+ )
+
+ assert res.status_code == 200
+
+ # Should still be able to access the page (should stay in English since invalid locale was ignored)
+ res = client.get(
+ url_for("watchlist.index"),
+ follow_redirects=True
+ )
+
+ assert res.status_code == 200
+ assert b"Cancel" in res.data, "Should remain in English when invalid locale is provided"
+
+
+def test_language_persistence_in_session(client, live_server, measure_memory_usage, datastore_path):
+ """
+ Test that the language preference persists across multiple requests
+ within the same session.
+ """
+
+ # Set language to Italian
+ res = client.get(
+ url_for("set_language", locale="it"),
+ follow_redirects=True
+ )
+
+ assert res.status_code == 200
+
+ # Make multiple requests - language should persist
+ for _ in range(3):
+ res = client.get(
+ url_for("watchlist.index"),
+ follow_redirects=True
+ )
+
+ assert res.status_code == 200
+ assert b"Annulla" in res.data, "Italian text should persist across requests"