diff --git a/client/src/locales/data-de.json b/client/src/locales/data-de.json
index b19b0a9..e610cdd 100644
--- a/client/src/locales/data-de.json
+++ b/client/src/locales/data-de.json
@@ -878,6 +878,7 @@
     "cleared": "Aktueller Chat gelöscht",
     "clearFailed": "Löschen fehlgeschlagen: {message}",
     "deviceRequired": "Bitte verbinden Sie zuerst ein Gerät",
+    "inputTooLong": "Nachricht zu lang, bitte auf maximal {max} Zeichen begrenzen",
     "deviceDisconnected": "Gerät getrennt",
     "loadHistoryFailed": "Laden des Verlaufs fehlgeschlagen: {message}",
     "loadChatFailed": "Laden des Chats fehlgeschlagen: {message}",
diff --git a/client/src/locales/data-en.json b/client/src/locales/data-en.json
index 1ba761d..bbefab8 100644
--- a/client/src/locales/data-en.json
+++ b/client/src/locales/data-en.json
@@ -883,6 +883,7 @@
     "cleared": "Current chat cleared",
     "clearFailed": "Clear failed: {message}",
     "deviceRequired": "Please connect a device first",
+    "inputTooLong": "Message too long, please keep it under {max} characters",
     "deviceDisconnected": "Device disconnected",
     "loadHistoryFailed": "Failed to load history: {message}",
     "loadChatFailed": "Failed to load chat: {message}",
diff --git a/client/src/locales/data-es.json b/client/src/locales/data-es.json
index 3b7cef0..32db59f 100644
--- a/client/src/locales/data-es.json
+++ b/client/src/locales/data-es.json
@@ -878,6 +878,7 @@
     "cleared": "Chat actual borrado",
     "clearFailed": "Error al borrar: {message}",
     "deviceRequired": "Conecte primero un dispositivo",
+    "inputTooLong": "Mensaje demasiado largo, límite de {max} caracteres",
     "deviceDisconnected": "Dispositivo desconectado",
     "loadHistoryFailed": "Error al cargar el historial: {message}",
     "loadChatFailed": "Error al cargar el chat: {message}",
diff --git a/client/src/locales/data-fr.json b/client/src/locales/data-fr.json
index 3f45d9c..e7f15da 100644
--- a/client/src/locales/data-fr.json
+++ b/client/src/locales/data-fr.json
@@ -878,6 +878,7 @@
     "cleared": "Chat actuel effacé",
     "clearFailed": "Échec de l'effacement : {message}",
     "deviceRequired": "Veuillez d'abord connecter un appareil",
+    "inputTooLong": "Message trop long, veuillez le limiter à {max} caractères",
     "deviceDisconnected": "Appareil déconnecté",
     "loadHistoryFailed": "Échec du chargement de l'historique : {message}",
     "loadChatFailed": "Échec du chargement du chat : {message}",
diff --git a/client/src/locales/data-zh-HK.json b/client/src/locales/data-zh-HK.json
index 9ff09e8..b0d89df 100644
--- a/client/src/locales/data-zh-HK.json
+++ b/client/src/locales/data-zh-HK.json
@@ -883,6 +883,7 @@
     "cleared": "已清空目前會話",
     "clearFailed": "清空失敗：{message}",
     "deviceRequired": "請先連接裝置",
+    "inputTooLong": "內容過長，請將輸入限制在 {max} 字以內",
     "deviceDisconnected": "裝置未連接",
     "loadHistoryFailed": "載入歷史失敗：{message}",
     "loadChatFailed": "載入會話失敗：{message}",
diff --git a/client/src/locales/data-zh.json b/client/src/locales/data-zh.json
index af3bfdc..4c5c108 100644
--- a/client/src/locales/data-zh.json
+++ b/client/src/locales/data-zh.json
@@ -883,6 +883,7 @@
     "cleared": "已清空当前会话",
     "clearFailed": "清空失败：{message}",
     "deviceRequired": "请先连接设备",
+    "inputTooLong": "内容过长，请将输入限制在 {max} 字以内",
     "deviceDisconnected": "设备未连接",
     "loadHistoryFailed": "加载历史失败：{message}",
     "loadChatFailed": "加载会话失败：{message}",
diff --git a/client/src/pages/AIPage.tsx b/client/src/pages/AIPage.tsx
index be80501..c353e01 100644
--- a/client/src/pages/AIPage.tsx
+++ b/client/src/pages/AIPage.tsx
@@ -202,6 +202,8 @@ function makeId() {
   return `${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;
 }
 
+const MAX_INPUT_LENGTH = 1000;
+
 export type AIPageVariant = "page" | "split";
 
 export interface AIPageProps {
@@ -422,6 +424,10 @@ export default function AIPage({ variant = "page", onClose }: AIPageProps = {})
     (question: string) => {
       const trimmed = question.trim();
       if (!trimmed || sending) return;
+      if (trimmed.length > MAX_INPUT_LENGTH) {
+        toast.error(formatText(aiText.inputTooLong, { max: MAX_INPUT_LENGTH }));
+        return;
+      }
       if (!mac || !deviceState || !api) {
         toast.error(aiText.deviceRequired);
         return;
@@ -595,12 +601,27 @@ export default function AIPage({ variant = "page", onClose }: AIPageProps = {})
     [input, send],
   );
 
-  const onInputChange = useCallback((e: React.ChangeEvent<HTMLTextAreaElement>) => {
-    setInput(e.target.value);
-    const el = e.target;
-    el.style.height = "auto";
-    el.style.height = `${Math.min(el.scrollHeight, 160)}px`;
-  }, []);
+  const overLimitToastShown = useRef(false);
+
+  const onInputChange = useCallback(
+    (e: React.ChangeEvent<HTMLTextAreaElement>) => {
+      const raw = e.target.value;
+      if (raw.length > MAX_INPUT_LENGTH) {
+        if (!overLimitToastShown.current) {
+          toast.error(formatText(aiText.inputTooLong, { max: MAX_INPUT_LENGTH }));
+          overLimitToastShown.current = true;
+        }
+        setInput(raw.slice(0, MAX_INPUT_LENGTH));
+      } else {
+        overLimitToastShown.current = false;
+        setInput(raw);
+      }
+      const el = e.target;
+      el.style.height = "auto";
+      el.style.height = `${Math.min(el.scrollHeight, 160)}px`;
+    },
+    [aiText],
+  );
 
   // ── 优化记录：对比对话框 & 应用/回滚 ──
   const [compareMsg, setCompareMsg] = useState<OptimizeUIMessage | null>(null);
@@ -880,6 +901,7 @@ export default function AIPage({ variant = "page", onClose }: AIPageProps = {})
             onChange={onInputChange}
             onKeyDown={onKeyDown}
             rows={1}
+            maxLength={MAX_INPUT_LENGTH}
             placeholder={aiText.inputPlaceholder}
             className="flex-1 bg-transparent outline-none resize-none text-[15px] text-white placeholder:text-white/35 py-1.5 px-1 max-h-40 leading-[1.4]"
           />