diff --git a/lib/model/store.dart b/lib/model/store.dart
index 6800fc6af1..ef73317e20 100644
--- a/lib/model/store.dart
+++ b/lib/model/store.dart
@@ -51,12 +51,19 @@ export 'database.dart' show Account, AccountsCompanion, AccountAlreadyExistsExce
 ///  * [LiveGlobalStore], the implementation of this class that
 ///    we use outside of tests.
 abstract class GlobalStore extends ChangeNotifier {
-  GlobalStore({required Iterable<Account> accounts})
-    : _accounts = Map.fromEntries(accounts.map((a) => MapEntry(a.id, a)));
+  GlobalStore({
+    required Iterable<Account> accounts,
+    required GlobalSettingsData globalSettings,
+  })
+    : _accounts = Map.fromEntries(accounts.map((a) => MapEntry(a.id, a))),
+      _globalSettings = globalSettings;
 
   /// A cache of the [Accounts] table in the underlying data store.
   final Map<int, Account> _accounts;
 
+  /// A cache of the [GlobalSettingsData] singleton in the underlying data store.
+  GlobalSettingsData _globalSettings;
+
   // TODO settings (those that are per-device rather than per-account)
   // TODO push token, and other data corresponding to GlobalSessionState
 
@@ -223,6 +230,23 @@ abstract class GlobalStore extends ChangeNotifier {
   /// Remove an account from the underlying data store.
   Future<void> doRemoveAccount(int accountId);
 
+  GlobalSettingsData get globalSettings => _globalSettings;
+
+  /// Update the global settings in the store, return the new version.
+  ///
+  /// The global settings must already exist in the store.
+  Future<GlobalSettingsData> updateGlobalSettings(GlobalSettingsCompanion data) async {
+    await doUpdateGlobalSettings(data);
+    _globalSettings = _globalSettings.copyWithCompanion(data);
+    notifyListeners();
+    return _globalSettings;
+  }
+
+  /// Update the global settings in the underlying data store.
+  ///
+  /// This should only be called from [updateGlobalSettings].
+  Future<void> doUpdateGlobalSettings(GlobalSettingsCompanion data);
+
   @override
   String toString() => '${objectRuntimeType(this, 'GlobalStore')}#${shortHash(this)}';
 }
@@ -757,6 +781,7 @@ class LiveGlobalStore extends GlobalStore {
   LiveGlobalStore._({
     required AppDatabase db,
     required super.accounts,
+    required super.globalSettings,
   }) : _db = db;
 
   @override
@@ -773,7 +798,10 @@ class LiveGlobalStore extends GlobalStore {
   static Future<GlobalStore> load() async {
     final db = AppDatabase(NativeDatabase.createInBackground(await _dbFile()));
     final accounts = await db.select(db.accounts).get();
-    return LiveGlobalStore._(db: db, accounts: accounts);
+    final globalSettings = await db.ensureGlobalSettings();
+    return LiveGlobalStore._(db: db,
+      accounts: accounts,
+      globalSettings: globalSettings);
   }
 
   /// The file path to use for the app database.
@@ -835,6 +863,12 @@ class LiveGlobalStore extends GlobalStore {
     assert(rowsAffected == 1);
   }
 
+  @override
+  Future<void> doUpdateGlobalSettings(GlobalSettingsCompanion data) async {
+    final rowsAffected = await _db.update(_db.globalSettings).write(data);
+    assert(rowsAffected == 1);
+  }
+
   @override
   String toString() => '${objectRuntimeType(this, 'LiveGlobalStore')}#${shortHash(this)}';
 }
diff --git a/lib/widgets/content.dart b/lib/widgets/content.dart
index f3b369e876..d4fdc8cec7 100644
--- a/lib/widgets/content.dart
+++ b/lib/widgets/content.dart
@@ -14,6 +14,7 @@ import '../generated/l10n/zulip_localizations.dart';
 import '../model/avatar_url.dart';
 import '../model/binding.dart';
 import '../model/content.dart';
+import '../model/database.dart';
 import '../model/internal_link.dart';
 import 'code_block.dart';
 import 'dialog.dart';
@@ -1342,17 +1343,20 @@ void _launchUrl(BuildContext context, String urlString) async {
     return;
   }
 
+  final globalSettings = GlobalStoreWidget.of(context).globalSettings;
   bool launched = false;
   String? errorMessage;
   try {
     launched = await ZulipBinding.instance.launchUrl(url,
-      mode: switch (defaultTargetPlatform) {
+      mode: switch ((globalSettings.browserPreference, defaultTargetPlatform)) {
+        (BrowserPreference.embedded, _) => UrlLaunchMode.inAppBrowserView,
+        (BrowserPreference.external, _) => UrlLaunchMode.externalApplication,
         // On iOS we prefer LaunchMode.externalApplication because (for
         // HTTP URLs) LaunchMode.platformDefault uses SFSafariViewController,
         // which gives an awkward UX as described here:
         //  https://chat.zulip.org/#narrow/stream/48-mobile/topic/in-app.20browser/near/1169118
-        TargetPlatform.iOS => UrlLaunchMode.externalApplication,
-        _ => UrlLaunchMode.platformDefault,
+        (BrowserPreference.unset, TargetPlatform.iOS) => UrlLaunchMode.externalApplication,
+        (BrowserPreference.unset, _) => UrlLaunchMode.platformDefault,
       });
   } on PlatformException catch (e) {
     errorMessage = e.message;
diff --git a/lib/widgets/theme.dart b/lib/widgets/theme.dart
index ec6cd81ce0..fd7ca6d277 100644
--- a/lib/widgets/theme.dart
+++ b/lib/widgets/theme.dart
@@ -1,16 +1,27 @@
 import 'package:flutter/material.dart';
 
 import '../api/model/model.dart';
+import '../model/database.dart';
 import 'content.dart';
 import 'emoji_reaction.dart';
 import 'message_list.dart';
 import 'channel_colors.dart';
+import 'store.dart';
 import 'text.dart';
 
 ThemeData zulipThemeData(BuildContext context) {
   final DesignVariables designVariables;
   final List<ThemeExtension> themeExtensions;
-  Brightness brightness = MediaQuery.platformBrightnessOf(context);
+  final globalSettings = GlobalStoreWidget.of(context).globalSettings;
+  Brightness brightness;
+  switch (globalSettings.themeSetting) {
+    case ThemeSetting.unset:
+      brightness = MediaQuery.platformBrightnessOf(context);
+    case ThemeSetting.light:
+      brightness = Brightness.light;
+    case ThemeSetting.dark:
+      brightness = Brightness.dark;
+  }
 
   // This applies Material 3's color system to produce a palette of
   // appropriately matching and contrasting colors for use in a UI.
diff --git a/test/example_data.dart b/test/example_data.dart
index d071307ec4..42c3662940 100644
--- a/test/example_data.dart
+++ b/test/example_data.dart
@@ -8,6 +8,7 @@ import 'package:zulip/api/model/submessage.dart';
 import 'package:zulip/api/route/messages.dart';
 import 'package:zulip/api/route/realm.dart';
 import 'package:zulip/api/route/channels.dart';
+import 'package:zulip/model/database.dart';
 import 'package:zulip/model/narrow.dart';
 import 'package:zulip/model/store.dart';
 
@@ -805,8 +806,16 @@ ChannelUpdateEvent channelUpdateEvent(
 // The entire per-account or global state.
 //
 
-TestGlobalStore globalStore({List<Account> accounts = const []}) {
-  return TestGlobalStore(accounts: accounts);
+const globalSettings = GlobalSettingsData(
+  themeSetting: ThemeSetting.unset,
+  browserPreference: BrowserPreference.unset,
+);
+
+TestGlobalStore globalStore({
+  List<Account> accounts = const [],
+  GlobalSettingsData globalSettings = globalSettings,
+}) {
+  return TestGlobalStore(accounts: accounts, globalSettings: globalSettings);
 }
 
 InitialSnapshot initialSnapshot({
diff --git a/test/model/binding.dart b/test/model/binding.dart
index 30eb40c17b..ab446b5bcb 100644
--- a/test/model/binding.dart
+++ b/test/model/binding.dart
@@ -11,6 +11,7 @@ import 'package:zulip/model/binding.dart';
 import 'package:zulip/model/store.dart';
 import 'package:zulip/widgets/app.dart';
 
+import '../example_data.dart' as eg;
 import 'test_store.dart';
 
 /// The binding instance used in tests.
@@ -85,7 +86,7 @@ class TestZulipBinding extends ZulipBinding {
   ///
   /// Tests that access this getter, or that mount a [GlobalStoreWidget],
   /// should clean up by calling [reset].
-  TestGlobalStore get globalStore => _globalStore ??= TestGlobalStore(accounts: []);
+  TestGlobalStore get globalStore => _globalStore ??= eg.globalStore();
   TestGlobalStore? _globalStore;
 
   bool _debugAlreadyLoadedStore = false;
diff --git a/test/model/store_test.dart b/test/model/store_test.dart
index 10e8698360..821d3e3fe5 100644
--- a/test/model/store_test.dart
+++ b/test/model/store_test.dart
@@ -406,7 +406,7 @@ void main() {
     late FakeApiConnection connection;
 
     Future<void> prepareStore({Account? account}) async {
-      globalStore = TestGlobalStore(accounts: []);
+      globalStore = eg.globalStore();
       account ??= eg.selfAccount;
       await globalStore.insertAccount(account.toCompanion(false));
       connection = (globalStore.apiConnectionFromAccount(account)
@@ -581,7 +581,7 @@ void main() {
     }
 
     Future<void> preparePoll({int? lastEventId}) async {
-      globalStore = TestGlobalStore(accounts: []);
+      globalStore = eg.globalStore();
       await globalStore.add(eg.selfAccount, eg.initialSnapshot(
         lastEventId: lastEventId));
       await globalStore.perAccount(eg.selfAccount.id);
@@ -1086,7 +1086,10 @@ void main() {
 }
 
 class LoadingTestGlobalStore extends TestGlobalStore {
-  LoadingTestGlobalStore({required super.accounts});
+  LoadingTestGlobalStore({
+    required super.accounts,
+    super.globalSettings = eg.globalSettings,
+  });
 
   Map<int, List<Completer<PerAccountStore>>> completers = {};
 
diff --git a/test/model/test_store.dart b/test/model/test_store.dart
index 2322e78d7a..898beccdde 100644
--- a/test/model/test_store.dart
+++ b/test/model/test_store.dart
@@ -1,6 +1,7 @@
 import 'package:zulip/api/model/events.dart';
 import 'package:zulip/api/model/initial_snapshot.dart';
 import 'package:zulip/api/model/model.dart';
+import 'package:zulip/model/database.dart';
 import 'package:zulip/model/store.dart';
 import 'package:zulip/widgets/store.dart';
 
@@ -22,7 +23,7 @@ import '../example_data.dart' as eg;
 ///
 /// See also [TestZulipBinding.globalStore], which provides one of these.
 class TestGlobalStore extends GlobalStore {
-  TestGlobalStore({required super.accounts});
+  TestGlobalStore({required super.accounts, required super.globalSettings});
 
   final Map<
     ({Uri realmUrl, int? zulipFeatureLevel, String? email, String? apiKey}),
@@ -157,6 +158,13 @@ class TestGlobalStore extends GlobalStore {
       store: store, initialSnapshot: initialSnapshot);
     return Future.value(store);
   }
+
+  GlobalSettingsData? _globalSettings;
+
+  @override
+  Future<void> doUpdateGlobalSettings(GlobalSettingsCompanion data) async {
+    _globalSettings = _globalSettings!.copyWithCompanion(data);
+  }
 }
 
 extension PerAccountStoreTestExtension on PerAccountStore {