diff --git a/islands/Chats/Chat.tsx b/islands/Chats/Chat.tsx
index dd66d1a3..09c6fda2 100644
--- a/islands/Chats/Chat.tsx
+++ b/islands/Chats/Chat.tsx
@@ -275,8 +275,10 @@ export default function Home(
                                         class="p-talk-chat-send__file"
                                         onClick={() => {
                                             if (Message) {
-                                                if (messages.length > 100) {
-                                                    
+                                                if (Message.length > 100) {
+                                                    alert(
+                                                        "100文字以内で入力してください",
+                                                    )
                                                     return
                                                 }
                                                 const data = {
diff --git a/routes/api/v1/main.ts b/routes/api/v1/main.ts
index 6f656f2d..ac70155e 100644
--- a/routes/api/v1/main.ts
+++ b/routes/api/v1/main.ts
@@ -9,6 +9,7 @@ import pubClient from "../../../util/redisClient.ts"
 const env = await load()
 const redisURL = env["REDIS_URL"]
 const redisch = env["REDIS_CH"]
+const maxMessage = Number(env["MAX_MESSAGE_LENGTH"])
 const subClient = redis.createClient({
     url: redisURL,
 })
@@ -215,6 +216,9 @@ async function sendMessage(
         return
     }
     if (session.roomType === "friend") {
+        if(message.length > maxMessage){
+            return
+        }
         const result = await messages.create({
             userid: session.uuid,
             roomid: roomID,
@@ -277,6 +281,9 @@ async function sendMessage(
         }
         const frienduuid = friend.userid
         const messageid = crypto.randomUUID()
+        if(message.length > maxMessage){
+            return
+        }
         await messages.create({
             userid: session.uuid,
             roomid: roomID,
diff --git a/routes/api/v1/server/talk/send.ts b/routes/api/v1/server/talk/send.ts
index d1794d89..888343e3 100644
--- a/routes/api/v1/server/talk/send.ts
+++ b/routes/api/v1/server/talk/send.ts
@@ -5,6 +5,7 @@ import { takosfetch } from "../../../../../util/takosfetch.ts"
 import { load } from "$std/dotenv/mod.ts"
 const env = await load()
 const redisch = env["REDIS_CH"]
+const maxMessage = Number(env["MAX_MESSAGE_LENGTH"])
 export const handler = {
     async POST(req: Request, ctx: any) {
         const data = await req.json()
@@ -62,6 +63,9 @@ export const handler = {
                 status: 400,
             })
         }
+        if(message.length > maxMessage){
+            return
+        }
         const result = await messages.create({
             userid: uuid,
             roomid,