diff --git a/docs/content.en/docs/release-notes/_index.md b/docs/content.en/docs/release-notes/_index.md
index 7fc24683..cb486295 100644
--- a/docs/content.en/docs/release-notes/_index.md
+++ b/docs/content.en/docs/release-notes/_index.md
@@ -36,6 +36,7 @@ Information about release notes of Coco Server is provided here.
 - fix: fix selection issue after renaming #800
 - fix: fix shortcut issue in windows context menu #804
 - fix: panic caused by "state() called before manage()" #806
+- fix: fix multiline input issue #808
 
 ### ✈️ Improvements
 
@@ -59,7 +60,6 @@ Information about release notes of Coco Server is provided here.
 - refactor: clean up unsupported characters from query string in Win Search #802
 - chore: display backtrace in panic log #805
 
-
 ## 0.6.0 (2025-06-29)
 
 ### ❌ Breaking changes
diff --git a/src/components/Search/AutoResizeTextarea.tsx b/src/components/Search/AutoResizeTextarea.tsx
index d6ce4c55..c455032a 100644
--- a/src/components/Search/AutoResizeTextarea.tsx
+++ b/src/components/Search/AutoResizeTextarea.tsx
@@ -1,17 +1,16 @@
-import { useBoolean, useDebounceFn } from "ahooks";
+import { useBoolean } from "ahooks";
 import {
-  useRef,
   useImperativeHandle,
   forwardRef,
   KeyboardEvent,
-  useEffect,
   useCallback,
+  ChangeEvent,
+  useRef,
+  useEffect,
 } from "react";
 import { useTranslation } from "react-i18next";
 
-const LINE_HEIGHT = 24; // 1.5rem
-const MAX_FIRST_LINE_WIDTH = 470; // Width in pixels for first line
-const MAX_HEIGHT = 240; // 15rem
+const MAX_HEIGHT = 240;
 
 interface AutoResizeTextareaProps {
   isChatMode: boolean;
@@ -21,6 +20,7 @@ interface AutoResizeTextareaProps {
   chatPlaceholder?: string;
   lineCount?: number;
   onLineCountChange?: (lineCount: number) => void;
+  firstLineMaxWidth: number;
 }
 
 // Forward ref to allow parent to interact with this component
@@ -35,87 +35,15 @@ const AutoResizeTextarea = forwardRef<
       setInput,
       handleKeyDown,
       chatPlaceholder,
-      lineCount = 1,
       onLineCountChange,
+      firstLineMaxWidth,
     },
     ref
   ) => {
     const { t } = useTranslation();
-    const textareaRef = useRef<HTMLTextAreaElement>(null);
     const [isComposition, { setTrue, setFalse }] = useBoolean();
-
-    // Memoize resize logic
-    const { run: debouncedResize } = useDebounceFn(
-      () => {
-        const textarea = textareaRef.current;
-        if (!textarea) return;
-        if (typeof window === "undefined" || typeof document === "undefined")
-          return;
-
-        // Reset height to auto to get the correct scrollHeight
-        textarea.style.height = "auto";
-
-        // Create a hidden span to measure first line width
-        const span = document.createElement("span");
-        span.style.visibility = "hidden";
-        span.style.position = "absolute";
-        span.style.whiteSpace = "pre";
-        span.style.font = window.getComputedStyle(textarea).font;
-
-        // Get first line content
-        const content = textarea.value;
-        const firstLineEnd =
-          content.indexOf("\n") === -1 ? content.length : content.indexOf("\n");
-        span.textContent = content.slice(0, firstLineEnd);
-        document.body.appendChild(span);
-
-        // Calculate lines based on first line width
-        const firstLineWidth = span.offsetWidth;
-        document.body.removeChild(span);
-
-        // Start with 1 line
-        let lines = 1;
-
-        // Add a line if first line exceeds max width
-        if (firstLineWidth > MAX_FIRST_LINE_WIDTH) {
-          lines += 1;
-        }
-
-        // Add lines based on scrollHeight for remaining content
-        const scrollHeight = textarea.scrollHeight;
-        const remainingLines = Math.floor(
-          (scrollHeight - LINE_HEIGHT) / LINE_HEIGHT
-        );
-        lines += Math.max(0, remainingLines);
-
-        // Calculate final height
-        const newHeight = Math.min(lines * LINE_HEIGHT, MAX_HEIGHT);
-
-        // Only update if height actually changed
-        if (textarea.style.height !== `${newHeight}px`) {
-          textarea.style.height = `${newHeight}px`;
-          onLineCountChange?.(lines);
-        }
-      },
-      { wait: 100 }
-    );
-
-    // Handle input changes and initial setup
-    useEffect(() => {
-      if (textareaRef.current) {
-        debouncedResize();
-      }
-    }, [input, debouncedResize]);
-
-    useEffect(() => {
-      if (textareaRef.current) {
-        requestAnimationFrame(() => {
-          // Set cursor position to end
-          const length = textareaRef.current?.value.length || 0;
-          textareaRef.current?.setSelectionRange(length, length);
-        });
-      }
-    }, [lineCount]);
+    const textareaRef = useRef<HTMLTextAreaElement>(null);
+    const calcRef = useRef<HTMLDivElement>(null);
 
     // Expose methods to the parent via ref
     useImperativeHandle(ref, () => ({
@@ -135,40 +63,67 @@ const AutoResizeTextarea = forwardRef<
       handleKeyDown?.(event);
     };
 
+    useEffect(() => {
+      const textarea = textareaRef.current;
+
+      if (!textarea || !calcRef.current) return;
+
+      if (!calcRef.current) return;
+
+      textarea.style.height = "auto";
+
+      const computedStyle = getComputedStyle(textarea);
+      const lineHeight = parseInt(computedStyle.lineHeight);
+      let height = lineHeight;
+      let minHeight = lineHeight;
+
+      if (calcRef.current?.offsetWidth >= firstLineMaxWidth - 32) {
+        minHeight = lineHeight * 2;
+        height = Math.min(
+          Math.max(minHeight, textarea.scrollHeight),
+          MAX_HEIGHT
+        );
+      }
+
+      textarea.style.height = `${height}px`;
+      textarea.style.minHeight = `${minHeight}px`;
+
+      onLineCountChange?.(height / lineHeight);
+    }, [input, firstLineMaxWidth]);
+
     const handleChange = useCallback(
-      (e: React.ChangeEvent<HTMLTextAreaElement>) => {
-        setInput(e.target.value);
+      (event: ChangeEvent<HTMLTextAreaElement>) => {
+        setInput(event.currentTarget.value);
       },
       [setInput]
     );
 
     return (
-      <textarea
-        ref={textareaRef}
-        id={isChatMode ? "chat-textarea" : "search-textarea"}
-        autoFocus
-        autoComplete="off"
-        autoCapitalize="none"
-        spellCheck="false"
-        className="text-base flex-1 outline-none w-full min-w-[200px] text-[#333] dark:text-[#d8d8d8] placeholder-text-xs placeholder-[#999] dark:placeholder-gray-500 bg-transparent custom-scrollbar"
-        placeholder={chatPlaceholder || t("search.textarea.placeholder")}
-        aria-label={t("search.textarea.ariaLabel")}
-        value={input}
-        onChange={handleChange}
-        onKeyDown={handleKeyPress}
-        onCompositionStart={setTrue}
-        onCompositionEnd={() => {
-          setTimeout(setFalse, 0);
-        }}
-        rows={1}
-        style={{
-          resize: "none", // Prevent manual resize
-          overflow: "auto",
-          minHeight: "1.5rem",
-          maxHeight: "13.5rem", // Limit height to 9 rows (9 * 1.5 line-height)
-          lineHeight: "1.5rem", // Line height to match row height
-        }}
-      />
+      <>
+        <textarea
+          ref={textareaRef}
+          id={isChatMode ? "chat-textarea" : "search-textarea"}
+          autoFocus
+          autoComplete="off"
+          autoCapitalize="none"
+          spellCheck="false"
+          className="text-base flex-1 outline-none w-full min-w-[200px] text-[#333] dark:text-[#d8d8d8] placeholder-text-xs placeholder-[#999] dark:placeholder-gray-500 bg-transparent custom-scrollbar resize-none overflow-y-auto"
+          placeholder={chatPlaceholder || t("search.textarea.placeholder")}
+          aria-label={t("search.textarea.ariaLabel")}
+          value={input}
+          onChange={handleChange}
+          onKeyDown={handleKeyPress}
+          onCompositionStart={setTrue}
+          onCompositionEnd={() => {
+            setTimeout(setFalse, 0);
+          }}
+          rows={1}
+        />
+
+        <div ref={calcRef} className="absolute whitespace-nowrap -z-10">
+          {input}
+        </div>
+      </>
     );
   }
 );
diff --git a/src/components/Search/InputBox.tsx b/src/components/Search/InputBox.tsx
index 01eb817f..1b4028f8 100644
--- a/src/components/Search/InputBox.tsx
+++ b/src/components/Search/InputBox.tsx
@@ -1,6 +1,6 @@
 import { useCallback, useEffect, useMemo, useRef, useState } from "react";
 import { useTranslation } from "react-i18next";
-import { useKeyPress } from "ahooks";
+import { useKeyPress, useSize } from "ahooks";
 
 import AutoResizeTextarea from "./AutoResizeTextarea";
 import { useChatStore } from "@/stores/chatStore";
@@ -19,6 +19,7 @@ import { useExtensionsStore } from "@/stores/extensionsStore";
 import AudioRecording from "../AudioRecording";
 import { isDefaultServer } from "@/utils";
 import { useTauriFocus } from "@/hooks/useTauriFocus";
+import clsx from "clsx";
 
 interface ChatInputProps {
   onSend: (message: string) => void;
@@ -199,29 +200,39 @@ export default function ChatInput({
 
   const { currentService } = useConnectStore();
   const [visibleAudioInput, setVisibleAudioInput] = useState(false);
+  const containerRef = useRef<HTMLDivElement>(null);
+  const containerSize = useSize(containerRef);
+  const searchIconRef = useRef<HTMLDivElement>(null);
+  const searchIconSize = useSize(searchIconRef);
+  const extraIconRef = useRef<HTMLDivElement>(null);
+  const extraIconSize = useSize(extraIconRef);
 
   useEffect(() => {
     setVisibleAudioInput(isDefaultServer());
   }, [currentService]);
 
   const renderSearchIcon = () => (
-    <SearchIcons
-      lineCount={lineCount}
-      isChatMode={isChatMode}
-      assistant={askAIRef.current}
-    />
+    <div ref={searchIconRef} className="w-fit">
+      <SearchIcons
+        lineCount={lineCount}
+        isChatMode={isChatMode}
+        assistant={askAIRef.current}
+      />
+    </div>
   );
 
   const renderExtraIcon = () => (
-    <div className="flex items-center gap-2">
-      <ChatIcons
-        lineCount={lineCount}
-        isChatMode={isChatMode}
-        curChatEnd={curChatEnd}
-        inputValue={inputValue}
-        onSend={onSend}
-        disabledChange={disabledChange}
-      />
+    <div ref={extraIconRef} className="flex items-center gap-2 w-fit">
+      {isChatMode && (
+        <ChatIcons
+          lineCount={lineCount}
+          isChatMode={isChatMode}
+          curChatEnd={curChatEnd}
+          inputValue={inputValue}
+          onSend={onSend}
+          disabledChange={disabledChange}
+        />
+      )}
 
       {!isChatMode &&
         (sourceData || visibleExtensionStore || selectedExtension) && (
@@ -291,55 +302,63 @@ export default function ChatInput({
     </div>
   );
 
-  const renderTextarea = () => (
-    <VisibleKey
-      shortcut={returnToInput}
-      rootClassName="flex-1 flex items-center justify-center"
-      shortcutClassName="!left-0 !translate-x-0"
-    >
-      <AutoResizeTextarea
-        ref={textareaRef}
-        isChatMode={isChatMode}
-        input={inputValue}
-        setInput={handleInputChange}
-        handleKeyDown={handleKeyDownAutoResizeTextarea}
-        chatPlaceholder={
-          isChatMode
-            ? assistantConfig.placeholder || chatPlaceholder
-            : goAskAi
-            ? assistantDetail?._source?.chat_settings?.placeholder
-            : searchPlaceholder || t("search.input.searchPlaceholder")
-        }
-        lineCount={lineCount}
-        onLineCountChange={setLineCount}
-      />
-    </VisibleKey>
-  );
+  const renderTextarea = () => {
+    return (
+      <VisibleKey
+        shortcut={returnToInput}
+        rootClassName="flex-1 flex items-center justify-center"
+        shortcutClassName="!left-0 !translate-x-0"
+      >
+        <AutoResizeTextarea
+          ref={textareaRef}
+          isChatMode={isChatMode}
+          input={inputValue}
+          setInput={handleInputChange}
+          handleKeyDown={handleKeyDownAutoResizeTextarea}
+          chatPlaceholder={
+            isChatMode
+              ? assistantConfig.placeholder || chatPlaceholder
+              : goAskAi
+              ? assistantDetail?._source?.chat_settings?.placeholder
+              : searchPlaceholder || t("search.input.searchPlaceholder")
+          }
+          lineCount={lineCount}
+          onLineCountChange={setLineCount}
+          firstLineMaxWidth={
+            (containerSize?.width ?? 0) -
+            (searchIconSize?.width ?? 0) -
+            (extraIconSize?.width ?? 0)
+          }
+        />
+      </VisibleKey>
+    );
+  };
 
   return (
     <div className={`w-full relative`}>
       <div
         className={`p-2 flex items-center dark:text-[#D8D8D8] bg-[#ededed] dark:bg-[#202126] rounded-md transition-all relative overflow-hidden`}
       >
-        {lineCount === 1 ? (
-          <div className="relative flex items-center gap-2 w-full">
-            {renderSearchIcon()}
+        <div
+          ref={containerRef}
+          className={clsx("relative w-full", {
+            "flex items-center gap-2": lineCount === 1,
+          })}
+        >
+          {lineCount === 1 && renderSearchIcon()}
 
-            {renderTextarea()}
+          {renderTextarea()}
 
-            {renderExtraIcon()}
-          </div>
-        ) : (
-          <div className="relative w-full">
-            {renderTextarea()}
+          {lineCount === 1 && renderExtraIcon()}
 
+          {lineCount > 1 && (
             <div className="flex items-center mt-2">
               <div className="flex-1">{renderSearchIcon()}</div>
 
               <div className="self-end">{renderExtraIcon()}</div>
             </div>
-          </div>
-        )}
+          )}
+        </div>
       </div>
 
       <InputControls