diff --git a/src/App.tsx b/src/App.tsx
index 5bfa1f8..e717345 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -20,8 +20,14 @@ import type { EnvDefault } from "./env";
 
 type ThemeMode = "system" | "light" | "dark";
 type Language = "de" | "en" | "es" | "fr" | "nl";
+type DefaultSource = "auto" | "manual";
 
-const initialDefaults: EnvDefault[] = [{ key: "BOOTSTRAP_ADMIN_EMAIL", value: "admin@example.local" }];
+interface DefaultRow extends EnvDefault {
+  source: DefaultSource;
+  index?: number;
+}
+
+const initialDefaults: EnvDefault[] = [];
 
 const languageNames: Record<Language, string> = {
   de: "Deutsch",
@@ -50,8 +56,10 @@ const translations = {
     source: "Quelle",
     text: "Text",
     defaults: "Standardwerte",
-    defaultsHint: "Diese Werte überschreiben passende Keys im Output.",
+    defaultsHint: "Mögliche Standardwerte werden erkannt; eigene Werte überschreiben passende Keys im Output.",
     addDefault: "Standardwert hinzufügen",
+    autoDefault: "Auto",
+    manualDefault: "Manuell",
     key: "Key",
     value: "Wert",
     detected: "Erkannte Anforderungen",
@@ -87,8 +95,10 @@ const translations = {
     source: "Source",
     text: "Text",
     defaults: "Defaults",
-    defaultsHint: "These values override matching keys in the output.",
+    defaultsHint: "Possible defaults are detected; custom values override matching keys in the output.",
     addDefault: "Add default",
+    autoDefault: "Auto",
+    manualDefault: "Manual",
     key: "Key",
     value: "Value",
     detected: "Detected requirements",
@@ -124,8 +134,10 @@ const translations = {
     source: "Origen",
     text: "Texto",
     defaults: "Valores predeterminados",
-    defaultsHint: "Estos valores sobrescriben claves iguales en la salida.",
+    defaultsHint: "Se detectan valores posibles; los personalizados sobrescriben claves iguales.",
     addDefault: "Añadir valor",
+    autoDefault: "Auto",
+    manualDefault: "Manual",
     key: "Clave",
     value: "Valor",
     detected: "Requisitos detectados",
@@ -161,8 +173,10 @@ const translations = {
     source: "Source",
     text: "Texte",
     defaults: "Valeurs par défaut",
-    defaultsHint: "Ces valeurs remplacent les clés correspondantes dans la sortie.",
+    defaultsHint: "Les valeurs possibles sont détectées; les valeurs personnalisées remplacent les clés.",
     addDefault: "Ajouter",
+    autoDefault: "Auto",
+    manualDefault: "Manuel",
     key: "Clé",
     value: "Valeur",
     detected: "Exigences détectées",
@@ -198,8 +212,10 @@ const translations = {
     source: "Bron",
     text: "Tekst",
     defaults: "Standaardwaarden",
-    defaultsHint: "Deze waarden overschrijven gelijke keys in de output.",
+    defaultsHint: "Mogelijke standaardwaarden worden herkend; eigen waarden overschrijven keys.",
     addDefault: "Waarde toevoegen",
+    autoDefault: "Auto",
+    manualDefault: "Handmatig",
     key: "Key",
     value: "Waarde",
     detected: "Gedetecteerde eisen",
@@ -245,11 +261,122 @@ function readDefaults(): EnvDefault[] {
   }
 }
 
+function readIgnoredAutoDefaults(): string[] {
+  const stored = localStorage.getItem("envhelper-ignored-auto-defaults");
+  if (!stored) {
+    return [];
+  }
+
+  try {
+    const parsed = JSON.parse(stored) as string[];
+    return Array.isArray(parsed) ? parsed.filter(Boolean) : [];
+  } catch {
+    return [];
+  }
+}
+
 function readTheme(): ThemeMode {
   const stored = localStorage.getItem("envhelper-theme") as ThemeMode | null;
   return stored && themeLabels.includes(stored) ? stored : "system";
 }
 
+function inferAutomaticDefaults(input: string, manualDefaults: EnvDefault[], ignoredKeys: string[]): EnvDefault[] {
+  const manualKeys = new Set(manualDefaults.map((entry) => normalizeKey(entry.key)).filter(Boolean));
+  const ignored = new Set(ignoredKeys.map(normalizeKey).filter(Boolean));
+  const defaults = new Map<string, EnvDefault>();
+
+  for (const line of input.split(/\r?\n/)) {
+    const parsed = parseEnvAssignment(line);
+    if (!parsed) {
+      continue;
+    }
+
+    const normalizedKey = normalizeKey(parsed.key);
+    if (!normalizedKey || manualKeys.has(normalizedKey) || ignored.has(normalizedKey)) {
+      continue;
+    }
+
+    const value = inferDefaultValue(parsed.key, parsed.value);
+    if (value) {
+      defaults.set(normalizedKey, { key: parsed.key, value });
+    }
+  }
+
+  return [...defaults.values()].sort((a, b) => a.key.localeCompare(b.key));
+}
+
+function parseEnvAssignment(line: string): { key: string; value: string } | null {
+  const trimmed = line.trim();
+  if (!trimmed || trimmed.startsWith("#")) {
+    return null;
+  }
+
+  const normalized = trimmed.startsWith("export ") ? trimmed.slice(7).trimStart() : trimmed;
+  const equalsIndex = normalized.indexOf("=");
+  if (equalsIndex <= 0) {
+    return null;
+  }
+
+  return {
+    key: normalized.slice(0, equalsIndex).trim(),
+    value: normalized.slice(equalsIndex + 1).trim()
+  };
+}
+
+function inferDefaultValue(key: string, value: string): string | null {
+  const signal = normalizeKey(key);
+  const hasPlaceholder = /CHANGE_ME[A-Z0-9_]*/i.test(value);
+  const isEmpty = value.length === 0;
+  const shouldFillGeneric = hasPlaceholder || isEmpty;
+
+  if (signal === "NODE_ENV") {
+    return "production";
+  }
+
+  if (signal.includes("BOOTSTRAP_ADMIN_EMAIL") || signal.includes("ADMIN_EMAIL")) {
+    return "admin@example.local";
+  }
+
+  if (signal.includes("SUPPORT_EMAIL")) {
+    return "support@example.local";
+  }
+
+  if (signal.includes("CONTACT_EMAIL")) {
+    return "contact@example.local";
+  }
+
+  if (shouldFillGeneric && signal.endsWith("EMAIL")) {
+    return "admin@example.local";
+  }
+
+  if (shouldFillGeneric && (signal.includes("BASE_URL") || signal.endsWith("_URL") || signal.endsWith("_URI") || signal.includes("ORIGIN"))) {
+    return "https://example.local";
+  }
+
+  if (shouldFillGeneric && signal.includes("PORT")) {
+    if (signal.includes("POSTGRES")) {
+      return "5432";
+    }
+
+    if (signal.includes("REDIS")) {
+      return "6379";
+    }
+
+    return "3000";
+  }
+
+  return null;
+}
+
+function normalizeKey(key: string): string {
+  return key.trim().toUpperCase();
+}
+
+function addUnique(values: string[], value: string): string[] {
+  const normalized = normalizeKey(value);
+  return values.some((entry) => normalizeKey(entry) === normalized) ? values : [...values, value];
+}
+
 export default function App() {
   const [input, setInput] = useState("");
   const [loadedPath, setLoadedPath] = useState<string | null>(null);
@@ -258,8 +385,17 @@ export default function App() {
   const [settingsOpen, setSettingsOpen] = useState(false);
   const [themeMode, setThemeMode] = useState<ThemeMode>(readTheme);
   const [language, setLanguage] = useState<Language>(detectLanguage);
-  const [defaults, setDefaults] = useState<EnvDefault[]>(readDefaults);
+  const [manualDefaults, setManualDefaults] = useState<EnvDefault[]>(readDefaults);
+  const [ignoredAutoDefaults, setIgnoredAutoDefaults] = useState<string[]>(readIgnoredAutoDefaults);
   const t = translations[language];
+  const automaticDefaults = useMemo(() => inferAutomaticDefaults(input, manualDefaults, ignoredAutoDefaults), [input, manualDefaults, ignoredAutoDefaults]);
+  const defaults = useMemo<DefaultRow[]>(
+    () => [
+      ...automaticDefaults.map((entry) => ({ ...entry, source: "auto" as const })),
+      ...manualDefaults.map((entry, index) => ({ ...entry, index, source: "manual" as const }))
+    ],
+    [automaticDefaults, manualDefaults]
+  );
   const result = useMemo(() => transformEnv(input, defaults), [input, defaults, generation]);
 
   useEffect(() => {
@@ -272,8 +408,12 @@ export default function App() {
   }, [language]);
 
   useEffect(() => {
-    localStorage.setItem("envhelper-defaults", JSON.stringify(defaults));
-  }, [defaults]);
+    localStorage.setItem("envhelper-defaults", JSON.stringify(manualDefaults));
+  }, [manualDefaults]);
+
+  useEffect(() => {
+    localStorage.setItem("envhelper-ignored-auto-defaults", JSON.stringify(ignoredAutoDefaults));
+  }, [ignoredAutoDefaults]);
 
   async function openFile() {
     const file = await window.envHelper?.openFile();
@@ -293,16 +433,35 @@ export default function App() {
     window.setTimeout(() => setCopyLabel("copy"), 1400);
   }
 
-  function updateDefault(index: number, field: keyof EnvDefault, value: string) {
-    setDefaults((current) => current.map((entry, entryIndex) => (entryIndex === index ? { ...entry, [field]: value } : entry)));
+  function updateDefault(row: DefaultRow, field: keyof EnvDefault, value: string) {
+    if (row.source === "auto") {
+      setIgnoredAutoDefaults((current) => addUnique(current, row.key));
+      setManualDefaults((current) => [...current, { key: field === "key" ? value : row.key, value: field === "value" ? value : row.value }]);
+      return;
+    }
+
+    if (row.index === undefined) {
+      return;
+    }
+
+    setManualDefaults((current) => current.map((entry, entryIndex) => (entryIndex === row.index ? { ...entry, [field]: value } : entry)));
   }
 
   function addDefault() {
-    setDefaults((current) => [...current, { key: "", value: "" }]);
+    setManualDefaults((current) => [...current, { key: "", value: "" }]);
   }
 
-  function removeDefault(index: number) {
-    setDefaults((current) => current.filter((_, entryIndex) => entryIndex !== index));
+  function removeDefault(row: DefaultRow) {
+    if (row.source === "auto") {
+      setIgnoredAutoDefaults((current) => addUnique(current, row.key));
+      return;
+    }
+
+    if (row.index === undefined) {
+      return;
+    }
+
+    setManualDefaults((current) => current.filter((_, entryIndex) => entryIndex !== row.index));
   }
 
   return (
@@ -380,20 +539,21 @@ export default function App() {
           <PanelHeading icon={<Plus size={18} />} title={t.defaults} hint={t.defaultsHint} />
           <div className="defaultsList">
             {defaults.map((entry, index) => (
-              <div className="defaultRow" key={index}>
+              <div className="defaultRow" key={`${entry.source}-${entry.key}-${index}`}>
                 <input
                   aria-label={t.key}
                   placeholder={t.key}
                   value={entry.key}
-                  onChange={(event) => updateDefault(index, "key", event.target.value)}
+                  onChange={(event) => updateDefault(entry, "key", event.target.value)}
                 />
                 <input
                   aria-label={t.value}
                   placeholder={t.value}
                   value={entry.value}
-                  onChange={(event) => updateDefault(index, "value", event.target.value)}
+                  onChange={(event) => updateDefault(entry, "value", event.target.value)}
                 />
-                <button className="iconButton subtle" onClick={() => removeDefault(index)} title="Remove" type="button">
+                <span className={`defaultSource ${entry.source}`}>{entry.source === "auto" ? t.autoDefault : t.manualDefault}</span>
+                <button className="iconButton subtle" onClick={() => removeDefault(entry)} title="Remove" type="button">
                   <Trash2 size={16} />
                 </button>
               </div>
diff --git a/src/styles.css b/src/styles.css
index 1a4978c..c43a0f6 100644
--- a/src/styles.css
+++ b/src/styles.css
@@ -366,7 +366,32 @@ textarea::selection {
 .defaultRow {
   display: grid;
   gap: 8px;
-  grid-template-columns: minmax(120px, 0.9fr) minmax(140px, 1.1fr) 36px;
+  grid-template-columns: minmax(120px, 0.9fr) minmax(140px, 1.1fr) auto 36px;
+}
+
+.defaultSource {
+  align-items: center;
+  align-self: center;
+  border: 1px solid var(--border);
+  border-radius: 999px;
+  color: var(--muted);
+  display: inline-flex;
+  font-size: 0.68rem;
+  font-weight: 850;
+  height: 28px;
+  justify-content: center;
+  padding: 0 10px;
+  white-space: nowrap;
+}
+
+.defaultSource.auto {
+  background: var(--accent-soft);
+  border-color: color-mix(in srgb, var(--accent) 28%, var(--border));
+  color: var(--accent-strong);
+}
+
+.defaultSource.manual {
+  background: var(--surface-subtle);
 }
 
 .fullWidth {
@@ -543,7 +568,7 @@ textarea::selection {
   }
 
   .defaultRow {
-    grid-template-columns: 1fr 1fr 36px;
+    grid-template-columns: 1fr 1fr auto 36px;
   }
 
   .settingsPanel {