diff --git a/app/src/lib/nostr/languageNames.test.ts b/app/src/lib/nostr/languageNames.test.ts
new file mode 100644
index 0000000..8d64698
--- /dev/null
+++ b/app/src/lib/nostr/languageNames.test.ts
@@ -0,0 +1,17 @@
+import { describe, it, expect } from 'vitest';
+import { displayLanguage } from './languageNames';
+
+describe('displayLanguage', () => {
+  it('kennt deutsch', () => {
+    expect(displayLanguage('de')).toBe('Deutsch');
+  });
+  it('kennt english', () => {
+    expect(displayLanguage('en')).toBe('English');
+  });
+  it('fällt bei unbekanntem code auf uppercase-code zurück', () => {
+    expect(displayLanguage('fr')).toBe('FR');
+  });
+  it('fällt bei leerer sprache auf ? zurück', () => {
+    expect(displayLanguage('')).toBe('?');
+  });
+});
diff --git a/app/src/lib/nostr/languageNames.ts b/app/src/lib/nostr/languageNames.ts
new file mode 100644
index 0000000..1e2d44b
--- /dev/null
+++ b/app/src/lib/nostr/languageNames.ts
@@ -0,0 +1,9 @@
+const NAMES: Record<string, string> = {
+  de: 'Deutsch',
+  en: 'English'
+};
+
+export function displayLanguage(code: string): string {
+  if (!code) return '?';
+  return NAMES[code] ?? code.toUpperCase();
+}