diff --git a/routes/auth.js b/routes/auth.js
index 16247d5fb6695d92b707a11b86691bc7439658ea..6234891c859b246a006a85ae6e2976c1a8f40c50 100644
--- a/routes/auth.js
+++ b/routes/auth.js
@@ -1,4 +1,3 @@
-// routes/auth.js
 const express = require('express');
 const passport = require('passport');
 
@@ -15,17 +14,20 @@ router.get('/logout', (req, res) => {
     if (err) {
       return res.status(500).json({ error: 'Failed to logout' });
     }
-    res.redirect(process.env.FRONTEND_URL);
+    res.redirect(process.env.FRONTEND_URL || 'http://localhost:3000'); // 湲곕낯媛� �ㅼ젙
   });
 });
 
 // GET /auth/google
 router.get('/google', (req, res, next) => {
-  const redirectUrl = req.query.redirectUrl || process.env.FRONTEND_URL;
+  // 湲곕낯 redirectUrl �ㅼ젙
+  const redirectUrl = req.query.redirectUrl || process.env.FRONTEND_URL || 'http://localhost:3000';
 
-  // 由щ떎�대젆�� URL 寃�利�
-  const allowedDomains = [process.env.FRONTEND_URL];
-  if (!allowedDomains.some((domain) => redirectUrl.startsWith(domain))) {
+  // allowedDomains 諛곗뿴 �뺤씤 諛� 湲곕낯媛� �ㅼ젙
+  const allowedDomains = [process.env.FRONTEND_URL || 'http://localhost:3000'];
+
+  // redirectUrl 寃�利�
+  if (!allowedDomains.some((domain) => redirectUrl && redirectUrl.startsWith(domain))) {
     return res.status(400).json({ error: 'Invalid redirect URL' });
   }
 
@@ -41,10 +43,12 @@ router.get(
   passport.authenticate('google', { failureRedirect: '/auth/login' }),
   (req, res) => {
     // �몄뀡�먯꽌 redirectUrl 媛��몄삤湲�
-    const redirectUrl = req.session.redirectUrl || process.env.FRONTEND_URL;
+    const redirectUrl = req.session.redirectUrl || process.env.FRONTEND_URL || 'http://localhost:3000';
 
     // �몄뀡�먯꽌 redirectUrl �쒓굅
     req.session.redirectUrl = null;
+
+    // �꾨줎�몄뿏�쒕줈 由щ떎�대젆��
     res.redirect(redirectUrl);
   }
 );