diff --git a/api/refresh_invite_code.php b/api/refresh_invite_code.php
new file mode 100644
index 0000000..dc19cce
--- /dev/null
+++ b/api/refresh_invite_code.php
@@ -0,0 +1,27 @@
+<?php
+require_once __DIR__ . '/../auth/session.php';
+require_once __DIR__ . '/../includes/utils.php';
+requireLogin();
+
+if ($_SERVER['REQUEST_METHOD'] === 'POST') {
+    $server_id = $_POST['server_id'] ?? 0;
+    $user_id = $_SESSION['user_id'];
+    
+    require_once __DIR__ . '/../includes/permissions.php';
+    if (Permissions::hasPermission($user_id, $server_id, Permissions::MANAGE_SERVER) || Permissions::hasPermission($user_id, $server_id, Permissions::ADMINISTRATOR)) {
+        $new_invite_code = generateInviteCode();
+        $expires_at = date('c', time() + 1800); // ISO 8601 format
+        
+        $stmt = db()->prepare("UPDATE servers SET invite_code = ?, invite_code_expires_at = ? WHERE id = ?");
+        $stmt->execute([$new_invite_code, date('Y-m-d H:i:s', time() + 1800), $server_id]);
+        
+        echo json_encode([
+            'success' => true,
+            'invite_code' => $new_invite_code,
+            'expires_at' => $expires_at
+        ]);
+        exit;
+    }
+}
+
+echo json_encode(['success' => false, 'error' => 'Permission denied']);
diff --git a/api_v1_servers.php b/api_v1_servers.php
index 05b064d..9c786bd 100644
--- a/api_v1_servers.php
+++ b/api_v1_servers.php
@@ -1,5 +1,6 @@
 <?php
 require_once 'auth/session.php';
+require_once 'includes/utils.php';
 requireLogin();
 
 if ($_SERVER['REQUEST_METHOD'] === 'POST') {
@@ -8,11 +9,14 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST') {
     
     if ($action === 'join') {
         $invite_code = $_POST['invite_code'] ?? '';
-        $stmt = db()->prepare("SELECT id FROM servers WHERE invite_code = ?");
+        $stmt = db()->prepare("SELECT id, invite_code_expires_at FROM servers WHERE invite_code = ?");
         $stmt->execute([$invite_code]);
         $server = $stmt->fetch();
         
         if ($server) {
+            if ($server['invite_code_expires_at'] && strtotime($server['invite_code_expires_at']) < time()) {
+                die("This invite code has expired.");
+            }
             $stmt = db()->prepare("INSERT IGNORE INTO server_members (server_id, user_id) VALUES (?, ?)");
             $stmt->execute([$server['id'], $user_id]);
             header('Location: index.php?server_id=' . $server['id']);
@@ -56,9 +60,10 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST') {
             $db->beginTransaction();
             
             // Create server
-            $invite_code = substr(strtoupper(md5(uniqid())), 0, 8);
-            $stmt = $db->prepare("INSERT INTO servers (name, owner_id, invite_code, icon_url) VALUES (?, ?, ?, ?)");
-            $stmt->execute([$name, $user_id, $invite_code, $icon_url]);
+            $invite_code = generateInviteCode();
+            $expires_at = date('Y-m-d H:i:s', time() + 1800); // 30 minutes
+            $stmt = $db->prepare("INSERT INTO servers (name, owner_id, invite_code, icon_url, invite_code_expires_at) VALUES (?, ?, ?, ?, ?)");
+            $stmt->execute([$name, $user_id, $invite_code, $icon_url, $expires_at]);
             $server_id = $db->lastInsertId();
             
             // Add owner as member
diff --git a/assets/js/main.js b/assets/js/main.js
index 93261ba..edaef00 100644
--- a/assets/js/main.js
+++ b/assets/js/main.js
@@ -2796,4 +2796,61 @@ document.addEventListener('DOMContentLoaded', () => {
     };
     restoreCollapsedStates();
 
+    // Invite code refresh and timer
+    const refreshBtn = document.getElementById('refresh-invite-code-btn');
+    const inviteInput = document.getElementById('server-invite-code');
+    const timerContainer = document.getElementById('invite-code-timer');
+
+    if (refreshBtn) {
+        refreshBtn.addEventListener('click', async () => {
+            const formData = new FormData();
+            formData.append('server_id', window.activeServerId);
+            
+            try {
+                const resp = await fetch('api/refresh_invite_code.php', {
+                    method: 'POST',
+                    body: formData
+                });
+                const data = await resp.json();
+                
+                if (data.success) {
+                    if (inviteInput) inviteInput.value = data.invite_code;
+                    if (timerContainer) {
+                        timerContainer.dataset.expires = data.expires_at;
+                        timerContainer.innerHTML = 'Expires in: <span id="invite-timer-display">30:00</span>';
+                    }
+                } else {
+                    alert('Error: ' + data.error);
+                }
+            } catch (e) {
+                console.error(e);
+                alert('Failed to refresh invite code.');
+            }
+        });
+    }
+
+    function updateInviteTimer() {
+        const display = document.getElementById('invite-timer-display');
+        const container = document.getElementById('invite-code-timer');
+        if (!display || !container || !container.dataset.expires) return;
+
+        const expiresAt = new Date(container.dataset.expires).getTime();
+        const now = new Date().getTime();
+        const diff = expiresAt - now;
+
+        if (diff <= 0) {
+            container.innerHTML = '<span class="text-danger">Expired</span>';
+            return;
+        }
+
+        const minutes = Math.floor((diff % (1000 * 60 * 60)) / (1000 * 60));
+        const seconds = Math.floor((diff % (1000 * 60)) / 1000);
+
+        display.innerText = `${minutes.toString().padStart(2, '0')}:${seconds.toString().padStart(2, '0')}`;
+    }
+
+    if (timerContainer) {
+        setInterval(updateInviteTimer, 1000);
+        updateInviteTimer();
+    }
 });
diff --git a/auth/register.php b/auth/register.php
index 7435b37..b179479 100644
--- a/auth/register.php
+++ b/auth/register.php
@@ -14,11 +14,13 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST') {
             if (empty($invite_code)) {
                 $error = "An invitation code is required.";
             } else {
-                $stmt = db()->prepare("SELECT id FROM servers WHERE invite_code = ?");
+                $stmt = db()->prepare("SELECT id, invite_code_expires_at FROM servers WHERE invite_code = ?");
                 $stmt->execute([$invite_code]);
                 $server = $stmt->fetch();
                 if (!$server) {
                     $error = "Invalid invitation code.";
+                } elseif ($server['invite_code_expires_at'] && strtotime($server['invite_code_expires_at']) < time()) {
+                    $error = "This invitation code has expired.";
                 } else {
                     $server_id = $server['id'];
                 }
@@ -89,7 +91,7 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST') {
             <?php if (PRIVATE_REGISTRATION): ?>
             <div class="mb-3">
                 <label class="form-label">Invite Code</label>
-                <input type="text" name="invite_code" class="form-control" placeholder="Enter invitation code" required>
+                <input type="text" name="invite_code" class="form-control" placeholder="Ex: aB1!c2D3@4" required>
             </div>
             <?php endif; ?>
             <button type="submit" class="btn btn-blurple">Continue</button>
diff --git a/db/migrations/20260218_make_invite_code_binary.sql b/db/migrations/20260218_make_invite_code_binary.sql
new file mode 100644
index 0000000..9f93b19
--- /dev/null
+++ b/db/migrations/20260218_make_invite_code_binary.sql
@@ -0,0 +1,2 @@
+-- Migration to make invite_code case-sensitive
+ALTER TABLE servers MODIFY invite_code VARCHAR(16) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin;
diff --git a/includes/utils.php b/includes/utils.php
new file mode 100644
index 0000000..44c68f8
--- /dev/null
+++ b/includes/utils.php
@@ -0,0 +1,44 @@
+<?php
+
+/**
+ * Generates a secure random invite code.
+ * Requirements: lowercase, uppercase, digits, special characters.
+ * Length: 10 to 12 characters.
+ */
+function generateInviteCode($length = null) {
+    if ($length === null) {
+        $length = rand(10, 12);
+    }
+    
+    $chars = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!@#$%^&*()-_=+';
+    $code = '';
+    $max = strlen($chars) - 1;
+    
+    // Ensure at least one of each required type if possible, 
+    // but a simple random selection from the full set is usually sufficient 
+    // if the set is diverse enough and the length is 10-12.
+    // However, to be strictly compliant with "must have...", let's ensure it.
+    
+    $sets = [
+        'abcdefghijklmnopqrstuvwxyz',
+        'ABCDEFGHIJKLMNOPQRSTUVWXYZ',
+        '0123456789',
+        '!@#$%^&*()-_=+'
+    ];
+    
+    // Pick one from each set
+    foreach ($sets as $set) {
+        $code .= $set[random_int(0, strlen($set) - 1)];
+    }
+    
+    // Fill the rest
+    while (strlen($code) < $length) {
+        $code .= $chars[random_int(0, $max)];
+    }
+    
+    // Shuffle to avoid predictable pattern
+    $codeArray = str_split($code);
+    shuffle($codeArray);
+    
+    return implode('', $codeArray);
+}
diff --git a/index.php b/index.php
index 9135172..32b0534 100644
--- a/index.php
+++ b/index.php
@@ -1518,11 +1518,25 @@ async function handleSaveUserSettings(btn) {
                                 <label class="form-label text-uppercase fw-bold" style="font-size: 0.7em; color: var(--text-muted);">Invite Code</label>
                                 <?php 
                                     $invite = '';
-                                    foreach($servers as $s) if($s['id'] == $active_server_id) $invite = $s['invite_code'];
+                                    $expires_at = '';
+                                    foreach($servers as $s) {
+                                        if($s['id'] == $active_server_id) {
+                                            $invite = $s['invite_code'];
+                                            $expires_at = $s['invite_code_expires_at'] ? date('c', strtotime($s['invite_code_expires_at'])) : '';
+                                        }
+                                    }
                                 ?>
-                                <div class="input-group">
-                                    <input type="text" class="form-control bg-dark text-white border-0" value="<?php echo $invite; ?>" readonly>
-                                    <button class="btn btn-secondary" type="button" onclick="navigator.clipboard.writeText('<?php echo $invite; ?>')">Copy</button>
+                                <div class="input-group mb-2">
+                                    <input type="text" id="server-invite-code" class="form-control bg-dark text-white border-0" value="<?php echo $invite; ?>" readonly>
+                                    <button class="btn btn-secondary" type="button" onclick="navigator.clipboard.writeText(document.getElementById('server-invite-code').value)">Copy</button>
+                                    <button class="btn btn-primary" type="button" id="refresh-invite-code-btn">Refresh</button>
+                                </div>
+                                <div id="invite-code-timer" class="small text-muted" data-expires="<?php echo $expires_at; ?>">
+                                    <?php if ($expires_at): ?>
+                                        Expires in: <span id="invite-timer-display">--:--</span>
+                                    <?php else: ?>
+                                        No expiration set.
+                                    <?php endif; ?>
                                 </div>
                             </div>
 
@@ -1648,7 +1662,7 @@ async function handleSaveUserSettings(btn) {
                             <p style="color: var(--text-muted); font-size: 0.9em;">Enter an invite code to join an existing server.</p>
                             <div class="mb-3">
                                 <label class="form-label text-uppercase fw-bold" style="font-size: 0.7em; color: var(--text-muted);">Invite Code</label>
-                                <input type="text" name="invite_code" class="form-control" placeholder="GEN-123" required>
+                                <input type="text" name="invite_code" class="form-control" placeholder="Ex: aB1!c2D3@4" required>
                             </div>
                             <button type="submit" class="btn btn-success w-100" style="background-color: #23a559; border: none;">Join Server</button>
                         </form>
diff --git a/requests.log b/requests.log
index a6fc014..5e78734 100644
--- a/requests.log
+++ b/requests.log
@@ -642,3 +642,15 @@
 2026-02-18 16:17:10 - GET / - POST: []
 2026-02-18 16:20:19 - GET /?fl_project=38443 - POST: []
 2026-02-18 16:21:39 - GET /index.php - POST: []
+2026-02-18 16:27:32 - GET /?fl_project=38443 - POST: []
+2026-02-18 16:32:55 - GET / - POST: []
+2026-02-18 16:33:31 - GET /?fl_project=38443 - POST: []
+2026-02-18 16:33:40 - GET /index.php - POST: []
+2026-02-18 16:37:19 - GET / - POST: []
+2026-02-18 16:37:47 - GET /?fl_project=38443 - POST: []
+2026-02-18 16:39:21 - GET /index.php - POST: []
+2026-02-18 16:40:32 - GET /index.php - POST: []
+2026-02-18 16:43:32 - GET /?fl_project=38443 - POST: []
+2026-02-18 16:45:36 - GET / - POST: []
+2026-02-18 16:45:55 - GET /?fl_project=38443 - POST: []
+2026-02-18 16:47:17 - GET /index.php - POST: []