diff --git a/backend/src/constants/index.js b/backend/src/constants/index.js
index 2614455..e9e9098 100644
--- a/backend/src/constants/index.js
+++ b/backend/src/constants/index.js
@@ -1,10 +1,14 @@
 const { MATCH_STATUS, SUGGESTION_STATUS } = require('./statuses');
 const { ACCOUNT_TIER, FAIRNESS_SUPPORTER_PENALTY, FAIRNESS_COMFORT_PENALTY } = require('./tiers');
 
+// Message validation
+const MESSAGE_MAX_LENGTH = 2000;
+
 module.exports = {
   MATCH_STATUS,
   SUGGESTION_STATUS,
   ACCOUNT_TIER,
   FAIRNESS_SUPPORTER_PENALTY,
   FAIRNESS_COMFORT_PENALTY,
+  MESSAGE_MAX_LENGTH,
 };
diff --git a/backend/src/socket/index.js b/backend/src/socket/index.js
index ee7018d..c8d9e3b 100644
--- a/backend/src/socket/index.js
+++ b/backend/src/socket/index.js
@@ -2,6 +2,7 @@ const { Server } = require('socket.io');
 const { verifyToken } = require('../utils/auth');
 const { prisma } = require('../utils/db');
 const { ACTIONS, log: activityLog } = require('../services/activityLog');
+const { MESSAGE_MAX_LENGTH } = require('../constants');
 
 // Track active users in each event room
 const activeUsers = new Map(); // eventId -> Set of { socketId, userId, username, avatar }
@@ -310,6 +311,19 @@ function initializeSocket(httpServer) {
           return socket.emit('error', { message: 'Not in an event room' });
         }
 
+        // Validate message content
+        if (!content || typeof content !== 'string') {
+          return socket.emit('error', { message: 'Invalid message content' });
+        }
+
+        if (content.trim().length === 0) {
+          return socket.emit('error', { message: 'Message cannot be empty' });
+        }
+
+        if (content.length > MESSAGE_MAX_LENGTH) {
+          return socket.emit('error', { message: `Message too long. Maximum ${MESSAGE_MAX_LENGTH} characters allowed.` });
+        }
+
         const eventId = socket.currentEventId;
         const roomName = socket.currentEventRoom;
 
@@ -434,6 +448,19 @@ function initializeSocket(httpServer) {
     // Send message to match room
     socket.on('send_match_message', async ({ matchId, content }) => {
       try {
+        // Validate message content
+        if (!content || typeof content !== 'string') {
+          return socket.emit('error', { message: 'Invalid message content' });
+        }
+
+        if (content.trim().length === 0) {
+          return socket.emit('error', { message: 'Message cannot be empty' });
+        }
+
+        if (content.length > MESSAGE_MAX_LENGTH) {
+          return socket.emit('error', { message: `Message too long. Maximum ${MESSAGE_MAX_LENGTH} characters allowed.` });
+        }
+
         const roomName = `match_${matchId}`;
 
         // Get match and its room
diff --git a/frontend/src/components/chat/ChatInput.jsx b/frontend/src/components/chat/ChatInput.jsx
index ce4a8e3..af48af9 100644
--- a/frontend/src/components/chat/ChatInput.jsx
+++ b/frontend/src/components/chat/ChatInput.jsx
@@ -1,7 +1,8 @@
 import { Send } from 'lucide-react';
+import { MESSAGE_MAX_LENGTH } from '../../constants';
 
 /**
- * Chat Input component with send button
+ * Chat Input component with send button and character counter
  *
  * @param {string} value - Input value
  * @param {function} onChange - Change handler for input
@@ -26,26 +27,42 @@ const ChatInput = ({
     onSubmit(e);
   };
 
+  const charCount = value.length;
+  const isNearLimit = charCount > MESSAGE_MAX_LENGTH * 0.8; // 80% of limit
+  const isOverLimit = charCount > MESSAGE_MAX_LENGTH;
+
   return (
-    <form onSubmit={handleSubmit} className={`flex space-x-2 ${className}`}>
-      <input
-        type="text"
-        value={value}
-        onChange={onChange}
-        placeholder={placeholder}
-        disabled={disabled}
-        autoFocus={autoFocus}
-        className="flex-1 px-4 py-2 border border-gray-300 rounded-lg focus:ring-primary-500 focus:border-primary-500 disabled:opacity-50 disabled:cursor-not-allowed"
-      />
-      <button
-        type="submit"
-        disabled={disabled || !value.trim()}
-        className="px-4 py-2 bg-primary-600 text-white rounded-lg hover:bg-primary-700 transition-colors disabled:opacity-50 disabled:cursor-not-allowed"
-        aria-label="Send message"
-      >
-        <Send className="w-5 h-5" />
-      </button>
-    </form>
+    <div className="space-y-1">
+      <form onSubmit={handleSubmit} className={`flex space-x-2 ${className}`}>
+        <input
+          type="text"
+          value={value}
+          onChange={onChange}
+          placeholder={placeholder}
+          disabled={disabled}
+          autoFocus={autoFocus}
+          maxLength={MESSAGE_MAX_LENGTH}
+          className="flex-1 px-4 py-2 border border-gray-300 rounded-lg focus:ring-primary-500 focus:border-primary-500 disabled:opacity-50 disabled:cursor-not-allowed"
+        />
+        <button
+          type="submit"
+          disabled={disabled || !value.trim() || isOverLimit}
+          className="px-4 py-2 bg-primary-600 text-white rounded-lg hover:bg-primary-700 transition-colors disabled:opacity-50 disabled:cursor-not-allowed"
+          aria-label="Send message"
+        >
+          <Send className="w-5 h-5" />
+        </button>
+      </form>
+
+      {/* Character counter - show when approaching limit */}
+      {isNearLimit && (
+        <div className="text-right">
+          <span className={`text-xs ${isOverLimit ? 'text-red-600' : 'text-gray-500'}`}>
+            {charCount}/{MESSAGE_MAX_LENGTH}
+          </span>
+        </div>
+      )}
+    </div>
   );
 };
 
diff --git a/frontend/src/constants/index.js b/frontend/src/constants/index.js
index ffcf2c7..e2ff519 100644
--- a/frontend/src/constants/index.js
+++ b/frontend/src/constants/index.js
@@ -5,3 +5,6 @@ export {
   CONNECTION_STATE,
   SUGGESTION_TYPE,
 } from './statuses';
+
+// Message validation
+export const MESSAGE_MAX_LENGTH = 2000;