diff --git a/src/app/[groupId]/tasklist/_components/task-list-date-picker.tsx b/src/app/[groupId]/tasklist/_components/task-list-date-picker.tsx
index e1899eb6..be903c1e 100644
--- a/src/app/[groupId]/tasklist/_components/task-list-date-picker.tsx
+++ b/src/app/[groupId]/tasklist/_components/task-list-date-picker.tsx
@@ -48,13 +48,21 @@ const TaskListDatePicker = ({
     setCurrentSunday(sunday);
     setWeek(getWeek(sunday));
     setSelectedDate(date);
+    setShowCalendar(false);
   };
 
   const handleChangeDay = (e: ChangeEvent<HTMLInputElement>) => {
     if (!currentSunday) return;
+    const selectedDay = Number(e.target.value);
     setDay(e.target.value);
+
+    const weekDays = week || [];
+    const dayIndex = weekDays.indexOf(selectedDay);
+
+    if (dayIndex === -1) return;
+
     const newDate = new Date(currentSunday);
-    newDate.setDate(Number(e.target.value));
+    newDate.setDate(currentSunday.getDate() + dayIndex);
     setSelectedDate(newDate);
   };
 
@@ -114,7 +122,11 @@ const TaskListDatePicker = ({
           <Button
             variant="none"
             className="h-6 w-6 rounded-full bg-gray-50"
-            onClick={() => setShowCalendar((prevState) => !prevState)}
+            onMouseDown={(e) => {
+              e.preventDefault();
+              e.stopPropagation();
+              setShowCalendar((prevState) => !prevState);
+            }}
           >
             <Icon icon="calendar" className="h-3 w-3 text-gray-800" />
           </Button>
diff --git a/src/app/addteam/_components/add-team-contents.tsx b/src/app/addteam/_components/add-team-contents.tsx
index 0879cf43..7f7d4a26 100644
--- a/src/app/addteam/_components/add-team-contents.tsx
+++ b/src/app/addteam/_components/add-team-contents.tsx
@@ -1,5 +1,6 @@
 "use client";
 
+import { useCallback } from "react";
 import { useForm } from "react-hook-form";
 import {
   ProfileEdit,
@@ -35,12 +36,15 @@ const AddTeamContents = () => {
     isUploading: isImageUploading,
   } = useProfileImageManager();
 
-  const onSubmit = (data: { name: string; image?: string }) => {
-    createGroup({
-      name: data.name,
-      ...(profileImage && { image: profileImage }),
-    });
-  };
+  const onSubmit = useCallback(
+    (data: { name: string; image?: string }) => {
+      createGroup({
+        name: data.name,
+        ...(profileImage && { image: profileImage }),
+      });
+    },
+    [createGroup, profileImage]
+  );
 
   return (
     <div className="flex flex-col items-start gap-8 px-[21px] pb-[74.5px] pt-[52.5px] tablet:gap-10 tablet:px-[45px] tablet:pb-[64px] tablet:pt-[61px]">
diff --git a/src/app/boards/[articleId]/_components/article-header/article-header.tsx b/src/app/boards/[articleId]/_components/article-header/article-header.tsx
index e46485cf..0e2095c7 100644
--- a/src/app/boards/[articleId]/_components/article-header/article-header.tsx
+++ b/src/app/boards/[articleId]/_components/article-header/article-header.tsx
@@ -46,7 +46,9 @@ const ArticleHeader = ({ article }: ArticleHeaderProps) => {
     <>
       <div className="flex w-full flex-col gap-4 pb-[16px] tablet:pb-[28px]">
         <div className="flex items-center justify-between">
-          <h2 className="text-xl font-bold text-blue-700">{article.title}</h2>
+          <h2 className="break-all text-xl font-bold text-blue-700">
+            {article.title}
+          </h2>
           {isWriter && (
             <Dropdown
               trigger={
diff --git a/src/app/boards/[articleId]/edit/_components/article-edit-contents/article-edit-contents.tsx b/src/app/boards/[articleId]/edit/_components/article-edit-contents/article-edit-contents.tsx
index db5f54ea..28d6bf64 100644
--- a/src/app/boards/[articleId]/edit/_components/article-edit-contents/article-edit-contents.tsx
+++ b/src/app/boards/[articleId]/edit/_components/article-edit-contents/article-edit-contents.tsx
@@ -13,6 +13,7 @@ import {
 import usePatchArticle from "@/hooks/api/articles/use-patch-article";
 import { Article } from "@/types/article";
 import { filterProfanity } from "@/utils/profanityFilter";
+import { MAX_ARTICLE_TITLE_LENGTH } from "@/app/boards/_constants/article";
 
 interface ArticleEditContentsProps {
   article: Article;
@@ -29,6 +30,7 @@ const ArticleEditContents = ({ article }: ArticleEditContentsProps) => {
     register,
     handleSubmit,
     formState: { errors },
+    watch,
   } = useForm<EditFormData>({
     defaultValues: {
       title: article.title,
@@ -39,6 +41,7 @@ const ArticleEditContents = ({ article }: ArticleEditContentsProps) => {
   const [images, setImages] = useState<string[]>(
     article.image ? [article.image] : []
   );
+  const titleValue = watch("title") || "";
 
   const handleImagesChange = useCallback((imgs: string[]) => {
     setImages(imgs);
@@ -76,15 +79,32 @@ const ArticleEditContents = ({ article }: ArticleEditContentsProps) => {
     >
       <h2 className="pb-[32px] text-xl font-bold text-blue-700">게시글 수정</h2>
 
-      <div className="flex flex-col items-start gap-2 pb-[24px] tablet:gap-3 tablet:pb-[32px]">
+      <div className="flex w-full flex-col items-start gap-2 pb-[24px] tablet:gap-3 tablet:pb-[32px]">
         <div className="flex gap-[6px]">
           <span className="text-lg font-bold text-blue-700">제목</span>
           <span className="text-red-200">*</span>
         </div>
-        <InputBox
-          placeholder="제목을 입력해주세요."
-          {...register("title", { required: "제목은 필수입니다" })}
-        />
+        <div className="relative flex w-full items-center">
+          <InputBox
+            placeholder="제목을 입력해주세요."
+            {...register("title", { required: "제목은 필수입니다" })}
+            maxLength={MAX_ARTICLE_TITLE_LENGTH}
+          />
+        </div>
+        {titleValue.length > 0 && (
+          <div className="w-full text-right">
+            <span
+              className={cn(
+                "text-xs",
+                titleValue.length === MAX_ARTICLE_TITLE_LENGTH
+                  ? "text-red-500"
+                  : "text-gray-500"
+              )}
+            >
+              {titleValue.length}/{MAX_ARTICLE_TITLE_LENGTH}
+            </span>
+          </div>
+        )}
         {errors.title && (
           <span className="text-sm text-red-500">{errors.title.message}</span>
         )}
diff --git a/src/app/boards/_components/boards-header/boards-header.tsx b/src/app/boards/_components/boards-header/boards-header.tsx
index 768d11e7..2c5f1fb1 100644
--- a/src/app/boards/_components/boards-header/boards-header.tsx
+++ b/src/app/boards/_components/boards-header/boards-header.tsx
@@ -2,16 +2,19 @@
 
 import cn from "@/utils/clsx";
 import { TextInput, Button, Icon } from "@/components/index";
-import { ChangeEvent } from "react";
+import { useCallback, ChangeEvent } from "react";
 
 const BoardsHeader = ({
   onSearch,
 }: {
   onSearch: (keyword: string) => void;
 }) => {
-  const handleSearch = (e: ChangeEvent<HTMLInputElement>) => {
-    onSearch(e.target.value);
-  };
+  const handleSearch = useCallback(
+    (e: ChangeEvent<HTMLInputElement>) => {
+      onSearch(e.target.value);
+    },
+    [onSearch]
+  );
 
   return (
     <div
diff --git a/src/app/boards/_constants/article.ts b/src/app/boards/_constants/article.ts
new file mode 100644
index 00000000..83e48763
--- /dev/null
+++ b/src/app/boards/_constants/article.ts
@@ -0,0 +1,6 @@
+/**
+ * 게시글 관련 상수
+ */
+
+/** 게시글 제목 최대 길이 */
+export const MAX_ARTICLE_TITLE_LENGTH = 200;
diff --git a/src/app/boards/write/_components/article-write-contents/article-write-contents.tsx b/src/app/boards/write/_components/article-write-contents/article-write-contents.tsx
index 48387be3..817b538c 100644
--- a/src/app/boards/write/_components/article-write-contents/article-write-contents.tsx
+++ b/src/app/boards/write/_components/article-write-contents/article-write-contents.tsx
@@ -12,6 +12,7 @@ import {
 } from "@/components/index";
 import { usePostArticle } from "@/hooks/api/articles/use-post-article";
 import { filterProfanity } from "@/utils/profanityFilter";
+import { MAX_ARTICLE_TITLE_LENGTH } from "@/app/boards/_constants/article";
 
 interface WriteFormData {
   title: string;
@@ -24,9 +25,11 @@ const ArticleWriteContents = () => {
     register,
     handleSubmit,
     formState: { errors },
+    watch,
   } = useForm<WriteFormData>();
   const { mutate, isPending } = usePostArticle();
   const [images, setImages] = useState<string[]>([]);
+  const titleValue = watch("title") || "";
 
   const handleImagesChange = useCallback((images: string[]) => {
     setImages(images);
@@ -61,15 +64,32 @@ const ArticleWriteContents = () => {
     >
       <h2 className="pb-[32px] text-xl font-bold text-blue-700">게시글 쓰기</h2>
 
-      <div className="flex flex-col items-start gap-2 pb-[24px] tablet:gap-3 tablet:pb-[32px]">
+      <div className="flex w-full flex-col items-start gap-2 pb-[24px] tablet:gap-3 tablet:pb-[32px]">
         <div className="flex gap-[6px]">
           <span className="text-lg font-bold text-blue-700">제목</span>
           <span className="text-red-200">*</span>
         </div>
-        <InputBox
-          placeholder="제목을 입력해주세요."
-          {...register("title", { required: "제목은 필수입니다" })}
-        />
+        <div className="relative flex w-full items-center">
+          <InputBox
+            placeholder="제목을 입력해주세요."
+            {...register("title", { required: "제목은 필수입니다" })}
+            maxLength={MAX_ARTICLE_TITLE_LENGTH}
+          />
+        </div>
+        {titleValue.length > 0 && (
+          <div className="w-full text-right">
+            <span
+              className={cn(
+                "text-xs",
+                titleValue.length === MAX_ARTICLE_TITLE_LENGTH
+                  ? "text-red-500"
+                  : "text-gray-500"
+              )}
+            >
+              {titleValue.length}/{MAX_ARTICLE_TITLE_LENGTH}
+            </span>
+          </div>
+        )}
         {errors.title && (
           <span className="text-sm text-red-500">{errors.title.message}</span>
         )}
diff --git a/src/components/input-box/input-box.tsx b/src/components/input-box/input-box.tsx
index fec6d35a..76aec96c 100644
--- a/src/components/input-box/input-box.tsx
+++ b/src/components/input-box/input-box.tsx
@@ -37,22 +37,27 @@ const InputBox = ({
   ...rest
 }: InputBoxProps) => {
   return (
-    <textarea
-      id={id}
-      ref={ref}
-      placeholder={placeholder}
+    <div
       className={cn(
-        "resize-none rounded-xl border border-gray-300 px-4 py-3 font-normal focus:border-blue-400 focus:outline-none",
-        "text-md placeholder:text-sm",
-        "tablet:text-lg tablet:placeholder:text-md",
-        "border-blue-400 placeholder-shown:border-gray-300 focus:border-blue-200",
-        "break-words",
+        "overflow-hidden rounded-xl border border-gray-300 focus-within:border-blue-200 has-[:placeholder-shown]:border-gray-300",
         width,
-        height,
-        className
+        height
       )}
-      {...rest}
-    />
+    >
+      <textarea
+        id={id}
+        ref={ref}
+        placeholder={placeholder}
+        className={cn(
+          "h-full w-full resize-none bg-transparent px-4 py-3 font-normal focus:outline-none",
+          "text-md placeholder:text-sm",
+          "tablet:text-lg tablet:placeholder:text-md",
+          "break-words",
+          className
+        )}
+        {...rest}
+      />
+    </div>
   );
 };
 
diff --git a/src/components/input-reply/input-reply.tsx b/src/components/input-reply/input-reply.tsx
index 284319f4..2c40af25 100644
--- a/src/components/input-reply/input-reply.tsx
+++ b/src/components/input-reply/input-reply.tsx
@@ -5,7 +5,7 @@ import cn from "@/utils/clsx";
 import Button from "../button/button";
 import Icon from "../icon/Icon";
 import TextareaAutosize from "react-textarea-autosize";
-import { pl } from "react-day-picker/locale";
+import { MAX_COMMENT_LENGTH } from "@/constants/comment";
 
 /**
  * @author junyeol
@@ -24,8 +24,11 @@ const InputReply = ({
   disabled = false,
 }: InputReplyProps) => {
   const [value, setValue] = useState("");
+
   const handleChange = (e: React.ChangeEvent<HTMLTextAreaElement>) => {
-    setValue(e.target.value);
+    if (e.target.value.length <= MAX_COMMENT_LENGTH) {
+      setValue(e.target.value);
+    }
   };
 
   const handleSubmit = () => {
@@ -37,13 +40,14 @@ const InputReply = ({
 
   return (
     <div className="flex w-full max-w-[780px] flex-col border-y-2 border-gray-300 py-3">
-      <div className="gap-6 pl-3 pr-3 flex-center">
+      <div className="flex items-center gap-6 pl-3 pr-3">
         <TextareaAutosize
           placeholder={placeholder}
           value={value}
           onChange={handleChange}
           disabled={disabled}
-          className="w-full max-w-[708px] resize-none text-xs text-blue-700 placeholder:text-gray-800 focus:outline-none tablet:text-md"
+          maxLength={MAX_COMMENT_LENGTH}
+          className="w-full resize-none text-xs text-blue-700 placeholder:text-gray-800 focus:outline-none tablet:text-md"
           minRows={1}
         />
         <Button
@@ -51,13 +55,27 @@ const InputReply = ({
           disabled={!value.trim() || disabled}
           onClick={handleSubmit}
           className={cn(
-            "h-[24px] w-[24px] flex-shrink-0 rounded-full",
+            "h-[24px] w-[24px] flex-shrink-0 self-end rounded-full",
             value ? "bg-blue-100" : "bg-gray-800"
           )}
         >
           <Icon icon="upArrow" className="h-4 w-4" />
         </Button>
       </div>
+      {value.length > 0 && (
+        <div className="pr-3 pt-1 text-right">
+          <span
+            className={cn(
+              "text-xs",
+              value.length === MAX_COMMENT_LENGTH
+                ? "text-red-500"
+                : "text-gray-500"
+            )}
+          >
+            {value.length}/{MAX_COMMENT_LENGTH}
+          </span>
+        </div>
+      )}
     </div>
   );
 };
diff --git a/src/components/reply/reply.tsx b/src/components/reply/reply.tsx
index d83f636f..898cccb6 100644
--- a/src/components/reply/reply.tsx
+++ b/src/components/reply/reply.tsx
@@ -10,6 +10,7 @@ import TextareaAutosize from "react-textarea-autosize";
 import DefaultProfile from "@/assets/icons/ic-user.svg";
 import { toDotDateString } from "@/utils/date-util";
 import { useGetUserInfoQuery } from "@/hooks/api/user/use-get-user-info-query";
+import { MAX_COMMENT_LENGTH } from "@/constants/comment";
 
 interface CommentProps {
   comment: Comment;
@@ -95,12 +96,29 @@ const Reply = ({ comment, onEdit, onDelete }: CommentProps) => {
 
         {isEditing ? (
           <div className="flex flex-col gap-2">
-            <TextareaAutosize
-              value={editedContent}
-              onChange={(e) => setEditedContent(e.target.value)}
-              className="w-full resize-none rounded-lg border border-blue-400 px-2 py-2 text-md leading-relaxed focus:outline-none"
-              minRows={3}
-            />
+            <div className="relative">
+              <TextareaAutosize
+                value={editedContent}
+                onChange={(e) => {
+                  if (e.target.value.length <= MAX_COMMENT_LENGTH) {
+                    setEditedContent(e.target.value);
+                  }
+                }}
+                maxLength={MAX_COMMENT_LENGTH}
+                className="w-full resize-none rounded-lg border border-blue-400 px-2 pb-6 pt-2 text-md leading-relaxed focus:outline-none"
+                minRows={3}
+              />
+              <span
+                className={cn(
+                  "absolute bottom-4 right-2 text-xs",
+                  editedContent.length === MAX_COMMENT_LENGTH
+                    ? "text-red-500"
+                    : "text-gray-500"
+                )}
+              >
+                {editedContent.length}/{MAX_COMMENT_LENGTH}
+              </span>
+            </div>
             <div className="flex gap-2">
               <Button
                 onClick={handleEdit}
@@ -119,7 +137,7 @@ const Reply = ({ comment, onEdit, onDelete }: CommentProps) => {
             </div>
           </div>
         ) : (
-          <p className="w-full text-md leading-relaxed text-gray-800 tablet:max-w-[464px] pc:max-w-[704px]">
+          <p className="w-full whitespace-pre-wrap break-words text-md leading-relaxed text-gray-800 tablet:max-w-[464px] pc:max-w-[665px]">
             {editedContent}
           </p>
         )}
diff --git a/src/constants/comment.ts b/src/constants/comment.ts
new file mode 100644
index 00000000..7edf56d2
--- /dev/null
+++ b/src/constants/comment.ts
@@ -0,0 +1,6 @@
+/**
+ * 댓글 관련 상수
+ */
+
+/** 댓글 내용 최대 길이 */
+export const MAX_COMMENT_LENGTH = 255;
diff --git a/src/utils/date-util.ts b/src/utils/date-util.ts
index edfd5ea9..80d14cf6 100644
--- a/src/utils/date-util.ts
+++ b/src/utils/date-util.ts
@@ -44,7 +44,7 @@ export const toKoreanDateWithTimeString = (timestamp: string) => {
  * @returns Date
  */
 export const getCurrentSunday = (date: Date) => {
-  const currentSunday = new Date();
+  const currentSunday = new Date(date);
   currentSunday.setDate(date.getDate() - date.getDay());
   currentSunday.setHours(0, 0, 0, 0);
   return currentSunday;