diff --git a/MCPForUnity/Editor/Services/IPackageUpdateService.cs b/MCPForUnity/Editor/Services/IPackageUpdateService.cs
index 9d4d2e487..9211c1c70 100644
--- a/MCPForUnity/Editor/Services/IPackageUpdateService.cs
+++ b/MCPForUnity/Editor/Services/IPackageUpdateService.cs
@@ -12,6 +12,23 @@ public interface IPackageUpdateService
         /// <returns>Update check result containing availability and latest version info</returns>
         UpdateCheckResult CheckForUpdate(string currentVersion);
 
+        /// <summary>
+        /// Returns a cached update result if one exists for today, or null if a network fetch is needed.
+        /// Main-thread only (reads EditorPrefs).
+        /// </summary>
+        UpdateCheckResult? TryGetCachedResult(string currentVersion);
+
+        /// <summary>
+        /// Performs only the network fetch and version comparison (no EditorPrefs access).
+        /// Safe to call from a background thread.
+        /// </summary>
+        UpdateCheckResult FetchAndCompare(string currentVersion);
+
+        /// <summary>
+        /// Caches a successful fetch result in EditorPrefs. Must be called from the main thread.
+        /// </summary>
+        void CacheFetchResult(string currentVersion, string fetchedVersion);
+
         /// <summary>
         /// Compares two version strings to determine if the first is newer than the second
         /// </summary>
diff --git a/MCPForUnity/Editor/Services/PackageUpdateService.cs b/MCPForUnity/Editor/Services/PackageUpdateService.cs
index 5f594e9ca..dab04098c 100644
--- a/MCPForUnity/Editor/Services/PackageUpdateService.cs
+++ b/MCPForUnity/Editor/Services/PackageUpdateService.cs
@@ -14,6 +14,7 @@ namespace MCPForUnity.Editor.Services
     /// </summary>
     public class PackageUpdateService : IPackageUpdateService
     {
+        private const int DefaultRequestTimeoutMs = 3000;
         private const string LastCheckDateKey = EditorPrefKeys.LastUpdateCheck;
         private const string CachedVersionKey = EditorPrefKeys.LatestKnownVersion;
         private const string LastBetaCheckDateKey = EditorPrefKeys.LastUpdateCheck + ".beta";
@@ -81,6 +82,88 @@ public UpdateCheckResult CheckForUpdate(string currentVersion)
             };
         }
 
+        /// <inheritdoc/>
+        public UpdateCheckResult? TryGetCachedResult(string currentVersion)
+        {
+            bool isGitInstallation = IsGitInstallation();
+            string gitBranch = isGitInstallation ? GetGitUpdateBranch(currentVersion) : "main";
+            bool useBetaChannel = isGitInstallation && string.Equals(gitBranch, "beta", StringComparison.OrdinalIgnoreCase);
+
+            string lastCheckKey = isGitInstallation
+                ? (useBetaChannel ? LastBetaCheckDateKey : LastCheckDateKey)
+                : LastAssetStoreCheckDateKey;
+            string cachedVersionKey = isGitInstallation
+                ? (useBetaChannel ? CachedBetaVersionKey : CachedVersionKey)
+                : CachedAssetStoreVersionKey;
+
+            string lastCheckDate = EditorPrefs.GetString(lastCheckKey, "");
+            string cachedLatestVersion = EditorPrefs.GetString(cachedVersionKey, "");
+
+            if (lastCheckDate == DateTime.Now.ToString("yyyy-MM-dd") && !string.IsNullOrEmpty(cachedLatestVersion))
+            {
+                return new UpdateCheckResult
+                {
+                    CheckSucceeded = true,
+                    LatestVersion = cachedLatestVersion,
+                    UpdateAvailable = IsNewerVersion(cachedLatestVersion, currentVersion),
+                    Message = "Using cached version check"
+                };
+            }
+
+            return null;
+        }
+
+        /// <inheritdoc/>
+        public UpdateCheckResult FetchAndCompare(string currentVersion)
+        {
+            bool isGitInstallation = IsGitInstallation();
+            string gitBranch = isGitInstallation ? GetGitUpdateBranch(currentVersion) : "main";
+
+            string latestVersion = isGitInstallation
+                ? FetchLatestVersionFromGitHub(gitBranch)
+                : FetchLatestVersionFromAssetStoreJson();
+
+            if (!string.IsNullOrEmpty(latestVersion))
+            {
+                return new UpdateCheckResult
+                {
+                    CheckSucceeded = true,
+                    LatestVersion = latestVersion,
+                    UpdateAvailable = IsNewerVersion(latestVersion, currentVersion),
+                    Message = "Successfully checked for updates"
+                };
+            }
+
+            return new UpdateCheckResult
+            {
+                CheckSucceeded = false,
+                UpdateAvailable = false,
+                Message = isGitInstallation
+                    ? "Failed to check for updates (network issue or offline)"
+                    : "Failed to check for Asset Store updates (network issue or offline)"
+            };
+        }
+
+        /// <inheritdoc/>
+        public void CacheFetchResult(string currentVersion, string fetchedVersion)
+        {
+            if (string.IsNullOrEmpty(fetchedVersion)) return;
+
+            bool isGitInstallation = IsGitInstallation();
+            string gitBranch = isGitInstallation ? GetGitUpdateBranch(currentVersion) : "main";
+            bool useBetaChannel = isGitInstallation && string.Equals(gitBranch, "beta", StringComparison.OrdinalIgnoreCase);
+
+            string lastCheckKey = isGitInstallation
+                ? (useBetaChannel ? LastBetaCheckDateKey : LastCheckDateKey)
+                : LastAssetStoreCheckDateKey;
+            string cachedVersionKey = isGitInstallation
+                ? (useBetaChannel ? CachedBetaVersionKey : CachedVersionKey)
+                : CachedAssetStoreVersionKey;
+
+            EditorPrefs.SetString(lastCheckKey, DateTime.Now.ToString("yyyy-MM-dd"));
+            EditorPrefs.SetString(cachedVersionKey, fetchedVersion);
+        }
+
         /// <inheritdoc/>
         public bool IsNewerVersion(string version1, string version2)
         {
@@ -265,7 +348,7 @@ protected virtual string FetchLatestVersionFromGitHub(string branch)
                 // - More reliable - doesn't require releases to be published
                 // - Direct source of truth from the main branch
 
-                using (var client = new WebClient())
+                using (var client = CreateWebClient())
                 {
                     client.Headers.Add("User-Agent", "Unity-MCPForUnity-UpdateChecker");
                     string packageJsonUrl = string.Equals(branch, "beta", StringComparison.OrdinalIgnoreCase)
@@ -304,7 +387,7 @@ protected virtual string FetchLatestVersionFromAssetStoreJson()
         {
             try
             {
-                using (var client = new WebClient())
+                using (var client = CreateWebClient())
                 {
                     client.Headers.Add("User-Agent", "Unity-MCPForUnity-AssetStoreUpdateChecker");
                     string jsonContent = client.DownloadString(AssetStoreVersionUrl);
@@ -322,5 +405,41 @@ protected virtual string FetchLatestVersionFromAssetStoreJson()
                 return null;
             }
         }
+
+        protected virtual WebClient CreateWebClient()
+        {
+            return new TimeoutWebClient(GetRequestTimeoutMs());
+        }
+
+        protected virtual int GetRequestTimeoutMs()
+        {
+            return DefaultRequestTimeoutMs;
+        }
+
+        private sealed class TimeoutWebClient : WebClient
+        {
+            private readonly int _timeoutMs;
+
+            public TimeoutWebClient(int timeoutMs)
+            {
+                _timeoutMs = timeoutMs;
+            }
+
+            protected override WebRequest GetWebRequest(Uri address)
+            {
+                var request = base.GetWebRequest(address);
+                if (request != null)
+                {
+                    request.Timeout = _timeoutMs;
+
+                    if (request is HttpWebRequest httpRequest)
+                    {
+                        httpRequest.ReadWriteTimeout = _timeoutMs;
+                    }
+                }
+
+                return request;
+            }
+        }
     }
 }
diff --git a/MCPForUnity/Editor/Windows/MCPForUnityEditorWindow.cs b/MCPForUnity/Editor/Windows/MCPForUnityEditorWindow.cs
index bf41353a6..174177ffc 100644
--- a/MCPForUnity/Editor/Windows/MCPForUnityEditorWindow.cs
+++ b/MCPForUnity/Editor/Windows/MCPForUnityEditorWindow.cs
@@ -52,6 +52,7 @@ public class MCPForUnityEditorWindow : EditorWindow
         private double lastRefreshTime = 0;
         private const double RefreshDebounceSeconds = 0.5;
         private bool updateCheckQueued = false;
+        private bool updateCheckInFlight = false;
 
         private enum ActivePanel
         {
@@ -352,7 +353,7 @@ private void UpdateVersionLabel()
 
         private void QueueUpdateCheck()
         {
-            if (updateCheckQueued)
+            if (updateCheckQueued || updateCheckInFlight)
             {
                 return;
             }
@@ -377,23 +378,61 @@ private void CheckForPackageUpdates()
                 return;
             }
 
-            try
+            // Main thread: resolve service + read EditorPrefs cache (both require main thread)
+            var updateService = MCPServiceLocator.Updates;
+            var cachedResult = updateService.TryGetCachedResult(currentVersion);
+            if (cachedResult != null)
             {
-                var result = MCPServiceLocator.Updates.CheckForUpdate(currentVersion);
-                if (result.CheckSucceeded && result.UpdateAvailable && !string.IsNullOrEmpty(result.LatestVersion))
+                ApplyUpdateCheckResult(cachedResult, currentVersion);
+                return;
+            }
+
+            // Background thread: network I/O only (no EditorPrefs access)
+            updateCheckInFlight = true;
+            Task.Run(() =>
+            {
+                try
                 {
-                    updateNotificationText.text = $"Update available: v{result.LatestVersion}  (current: v{currentVersion})";
-                    updateNotificationText.tooltip = $"Latest version: v{result.LatestVersion}\nCurrent version: v{currentVersion}";
-                    updateNotification.AddToClassList("visible");
+                    return updateService.FetchAndCompare(currentVersion);
                 }
-                else
+                catch (Exception ex)
                 {
-                    updateNotification.RemoveFromClassList("visible");
+                    McpLog.Info($"Package update check skipped: {ex.Message}");
+                    return null;
                 }
+            }).ContinueWith(t =>
+            {
+                EditorApplication.delayCall += () =>
+                {
+                    updateCheckInFlight = false;
+
+                    // Main thread: cache the result in EditorPrefs
+                    var result = t.Status == TaskStatus.RanToCompletion ? t.Result : null;
+                    if (result != null && result.CheckSucceeded && !string.IsNullOrEmpty(result.LatestVersion))
+                    {
+                        updateService.CacheFetchResult(currentVersion, result.LatestVersion);
+                    }
+
+                    if (this == null || updateNotification == null || updateNotificationText == null)
+                    {
+                        return;
+                    }
+
+                    ApplyUpdateCheckResult(result, currentVersion);
+                };
+            }, TaskScheduler.Default);
+        }
+
+        private void ApplyUpdateCheckResult(UpdateCheckResult result, string currentVersion)
+        {
+            if (result != null && result.CheckSucceeded && result.UpdateAvailable && !string.IsNullOrEmpty(result.LatestVersion))
+            {
+                updateNotificationText.text = $"Update available: v{result.LatestVersion}  (current: v{currentVersion})";
+                updateNotificationText.tooltip = $"Latest version: v{result.LatestVersion}\nCurrent version: v{currentVersion}";
+                updateNotification.AddToClassList("visible");
             }
-            catch (Exception ex)
+            else
             {
-                McpLog.Info($"Package update check skipped: {ex.Message}");
                 updateNotification.RemoveFromClassList("visible");
             }
         }