diff --git a/android/app/src/main/AndroidManifest.xml b/android/app/src/main/AndroidManifest.xml
index 39c30fe..1aa05eb 100644
--- a/android/app/src/main/AndroidManifest.xml
+++ b/android/app/src/main/AndroidManifest.xml
@@ -38,6 +38,10 @@
 
          In particular, this is used by the Flutter engine in io.flutter.plugin.text.ProcessTextPlugin. -->
     <queries>
+        <intent>
+            <action android:name="android.intent.action.VIEW" />
+            <data android:scheme="https" />
+        </intent>
         <intent>
             <action android:name="android.intent.action.PROCESS_TEXT"/>
             <data android:mimeType="text/plain"/>
diff --git a/lib/ui/screens/crash_screen.dart b/lib/ui/screens/crash_screen.dart
index 432ee6d..20575c3 100644
--- a/lib/ui/screens/crash_screen.dart
+++ b/lib/ui/screens/crash_screen.dart
@@ -90,11 +90,33 @@ class CrashScreen extends StatelessWidget {
               const SizedBox(height: 16),
               OutlinedButton.icon(
                 onPressed: () async {
-                  final url = Uri.parse(
-                    'https://codeberg.org/guettli/sharedinbox/issues/new',
+                  final title = Uri.encodeComponent(
+                    'Crash: ${exception.toString().split('\n').first}',
                   );
-                  if (await canLaunchUrl(url)) {
-                    await launchUrl(url, mode: LaunchMode.externalApplication);
+                  final body = Uri.encodeComponent(
+                    'Error: $exception\n\nStack Trace:\n$stackTrace',
+                  );
+                  final url = Uri.parse(
+                    'https://codeberg.org/guettli/sharedinbox/issues/new?title=$title&body=$body',
+                  );
+                  try {
+                    final launched = await launchUrl(
+                      url,
+                      mode: LaunchMode.externalApplication,
+                    );
+                    if (!launched && context.mounted) {
+                      ScaffoldMessenger.of(context).showSnackBar(
+                        const SnackBar(
+                          content: Text('Could not open browser.'),
+                        ),
+                      );
+                    }
+                  } catch (e) {
+                    if (context.mounted) {
+                      ScaffoldMessenger.of(context).showSnackBar(
+                        SnackBar(content: Text('Error: $e')),
+                      );
+                    }
                   }
                 },
                 icon: const Icon(Icons.bug_report),
diff --git a/pubspec.yaml b/pubspec.yaml
index 0e5d035..3587141 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -57,6 +57,8 @@ dev_dependencies:
   mockito: ^5.4.4
   fake_async: ^1.3.1
   sqlite3: any  # used directly in test/unit/db_test_helper.dart
+  url_launcher_platform_interface: ^2.3.2
+  plugin_platform_interface: ^2.1.8
 
 flutter:
   uses-material-design: true
diff --git a/test/widget/crash_screen_test.dart b/test/widget/crash_screen_test.dart
new file mode 100644
index 0000000..7f61030
--- /dev/null
+++ b/test/widget/crash_screen_test.dart
@@ -0,0 +1,63 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:mockito/mockito.dart';
+import 'package:plugin_platform_interface/plugin_platform_interface.dart';
+import 'package:sharedinbox/ui/screens/crash_screen.dart';
+import 'package:url_launcher_platform_interface/url_launcher_platform_interface.dart';
+
+class MockUrlLauncher extends Mock
+    with MockPlatformInterfaceMixin
+    implements UrlLauncherPlatform {
+  String? launchedUrl;
+  LaunchOptions? launchOptions;
+
+  @override
+  Future<bool> canLaunch(String? url) async => true;
+
+  @override
+  Future<bool> launchUrl(String? url, LaunchOptions? options) async {
+    launchedUrl = url;
+    launchOptions = options;
+    return true;
+  }
+}
+
+void main() {
+  testWidgets('CrashScreen shows error details and has a report button',
+      (tester) async {
+    tester.view.physicalSize = const Size(800, 1200);
+    tester.view.devicePixelRatio = 1.0;
+    addTearDown(() => tester.view.resetPhysicalSize());
+
+    final mock = MockUrlLauncher();
+    UrlLauncherPlatform.instance = mock;
+
+    const exception = 'TestException: something broke';
+    final stackTrace = StackTrace.current;
+
+    await tester.pumpWidget(
+      MaterialApp(
+        home: CrashScreen(exception: exception, stackTrace: stackTrace),
+      ),
+    );
+
+    expect(find.textContaining('TestException'), findsOneWidget);
+    expect(find.text('Report Issue on Codeberg'), findsOneWidget);
+
+    await tester.tap(find.text('Report Issue on Codeberg'));
+    await tester.pumpAndSettle();
+
+    expect(
+      mock.launchedUrl,
+      contains('https://codeberg.org/guettli/sharedinbox/issues/new'),
+    );
+    expect(
+      mock.launchedUrl,
+      contains('title=Crash%3A%20TestException%3A%20something%20broke'),
+    );
+    expect(
+      mock.launchedUrl,
+      contains('body=Error%3A%20TestException%3A%20something%20broke'),
+    );
+  });
+}