diff --git a/src/components/common/Dialog.tsx b/src/components/common/Dialog.tsx
index 75ee3e1c..2af42ea0 100644
--- a/src/components/common/Dialog.tsx
+++ b/src/components/common/Dialog.tsx
@@ -1,5 +1,5 @@
 import { PropsWithChildren, ReactNode, useEffect, useState } from 'react';
-import { css, Theme } from '@emotion/react';
+import { css, Theme, useTheme } from '@emotion/react';
 import { motion } from 'framer-motion';
 
 import PortalWrapper from '~/components/common/PortalWrapper';
@@ -10,13 +10,16 @@ import { dimBackdropCss } from './styles';
 export interface DialogProps {
   isShowing?: boolean;
   actionButtons: ReactNode;
+  dialogWidth?: number;
 }
 
 export default function Dialog({
   isShowing,
   children,
   actionButtons,
+  dialogWidth,
 }: PropsWithChildren<DialogProps>) {
+  const theme = useTheme();
   const [isSSR, setIsSSR] = useState(true);
 
   useEffect(() => {
@@ -34,7 +37,7 @@ export default function Dialog({
           animate="animate"
           exit="exit"
         >
-          <motion.div css={dialogCss} variants={defaultFadeInUpVariants}>
+          <motion.div css={dialogCss(theme, dialogWidth)} variants={defaultFadeInUpVariants}>
             <div css={dialogContentWrapperCss}>{children}</div>
             <div css={dialogButtonWrapperCss}>{actionButtons}</div>
           </motion.div>
@@ -54,14 +57,14 @@ const dimBackdropLayoutCss = (theme: Theme) => css`
   ${dimBackdropCss(theme)}
 `;
 
-const dialogCss = (theme: Theme) => css`
+const dialogCss = (theme: Theme, width = 311) => css`
   position: relative;
   display: flex;
   flex-direction: column;
   align-items: center;
   justify-content: flex-end;
 
-  width: 311px;
+  width: ${width}px;
   min-height: 200px;
 
   background-color: ${theme.color.background};
diff --git a/src/constants/localStorage.ts b/src/constants/localStorage.ts
index d872d6c6..15109fcd 100644
--- a/src/constants/localStorage.ts
+++ b/src/constants/localStorage.ts
@@ -2,3 +2,8 @@ export const localStorageUserTokenKeys = {
   accessToken: 'ygtlsat',
   refreshToken: 'ygtrfhtk',
 } as const;
+
+export const localStorageExtensionKeys = {
+  use: 'use-ygtang-extension',
+  refreshToken: 'ygte-refresh',
+} as const;
diff --git a/src/libs/api/client.ts b/src/libs/api/client.ts
index ce82c774..5e33f072 100644
--- a/src/libs/api/client.ts
+++ b/src/libs/api/client.ts
@@ -6,7 +6,7 @@ import CustomException from '~/exceptions/CustomException';
 import { errorMessage } from '~/exceptions/messages';
 import { ApiErrorScheme } from '~/exceptions/type';
 
-const DEVELOPMENT_API_URL = 'https://api.ygtang.xyz/api';
+const DEVELOPMENT_API_URL = 'https://ygtang.kr/api'; // TODO: 개발 서버 사망에 따른 개발 버전에서도 프로덕션 사용
 const PRODUCTION_API_URL = 'https://ygtang.kr/api';
 
 export const instance = axios.create({
diff --git a/src/pages/login/index.tsx b/src/pages/login/index.tsx
index 85b92dcb..4298996d 100644
--- a/src/pages/login/index.tsx
+++ b/src/pages/login/index.tsx
@@ -1,10 +1,13 @@
 import { FormEvent, useEffect, useState } from 'react';
 import { css, Theme } from '@emotion/react';
 
-import { CTAButton, GhostButton } from '~/components/common/Button';
+import { CTAButton, FilledButton, GhostButton } from '~/components/common/Button';
+import Dialog from '~/components/common/Dialog';
 import SEO from '~/components/common/SEO';
 import TextField from '~/components/common/TextField';
+import { localStorageExtensionKeys } from '~/constants/localStorage';
 import useMemberLoginMutation from '~/hooks/api/member/useMemberLoginMutation';
+import useReissueMutation from '~/hooks/api/reissue/useReissueMutation';
 import useDidUpdate from '~/hooks/common/useDidUpdate';
 import useInput from '~/hooks/common/useInput';
 import useInternalRouter from '~/hooks/common/useInternalRouter';
@@ -15,15 +18,99 @@ import { recordEvent } from '~/utils/analytics';
 import { validator } from '~/utils/validator';
 
 export default function Login() {
+  const [isPending, setIsPending] = useState(false);
+  const { push } = useInternalRouter();
+
+  const { handleFormSubmitEvent, email, password, emailError, passwordError } = useLoginPage({
+    setIsPending,
+  });
+  const {
+    canExtensionLogin,
+    handleExtensionLogin,
+    setUserCancelExtensionLogin,
+    userCancelExtensionLogin,
+  } = useExtensionAuth({ setIsPending });
+
+  return (
+    <>
+      <SEO title="로그인" />
+      <article css={loginCss}>
+        <div css={navMockupCss} />
+        <div css={loginIntroCardCss}></div>
+
+        <form css={loginFieldSetCss} onSubmit={handleFormSubmitEvent}>
+          <TextField
+            type="email"
+            label={'이메일 아이디'}
+            placeholder={'이메일을 입력해주세요'}
+            feedback={email.debouncedValue !== '' ? emailError || <>&nbsp;</> : <>&nbsp;</>}
+            isSuccess={email.debouncedValue.length > 0 && emailError === ''}
+            value={email.value}
+            onChange={email.onChange}
+            required
+            alertWhenFocused
+          />
+          <TextField
+            type="password"
+            label={'비밀번호'}
+            placeholder={'영문, 숫자 포함 6자 이상의 비밀번호'}
+            feedback={password.debouncedValue !== '' ? passwordError || <>&nbsp;</> : <>&nbsp;</>}
+            isSuccess={password.debouncedValue.length > 0 && passwordError === ''}
+            value={password.value}
+            onChange={password.onChange}
+            required
+            alertWhenFocused
+          />
+          <CTAButton type={'submit'} disabled={isPending}>
+            로그인
+          </CTAButton>
+        </form>
+        <GhostButton onClick={() => push('/password')}>비밀번호 찾기</GhostButton>
+        <div css={signUpTextWrapperCss}>
+          계정이 없으신가요?{' '}
+          <GhostButton size={'small'} onClick={() => push('/signup')}>
+            빠르게 가입하기
+          </GhostButton>
+        </div>
+        <Dialog
+          isShowing={!userCancelExtensionLogin && canExtensionLogin}
+          dialogWidth={300}
+          actionButtons={
+            <>
+              <FilledButton
+                colorType="light"
+                onClick={() => setUserCancelExtensionLogin(true)}
+                disabled={isPending}
+              >
+                다른 계정
+              </FilledButton>
+              <div css={dialogLongButtonCss}>
+                <FilledButton colorType="dark" onClick={handleExtensionLogin} disabled={isPending}>
+                  익스텐션 계정
+                </FilledButton>
+              </div>
+            </>
+          }
+        >
+          영감탱 익스텐션에 로그인되어 있습니다.
+          <br />
+          익스텐션 계정으로 로그인할까요?
+        </Dialog>
+      </article>
+    </>
+  );
+}
+
+function useLoginPage({ setIsPending }: { setIsPending: (value: boolean) => void }) {
   const { fireToast } = useToast();
   const email = useInput({});
   const password = useInput({});
-  const [isPending, setIsPending] = useState(false);
-  const [emailError, setEmailError] = useState('');
-  const [passwordError, setPasswordError] = useState('');
-  const { userLogin } = useUser();
   const { push } = useInternalRouter();
   const { getRedirect, goRedirect } = useLoginRedirect();
+  const { userLogin } = useUser();
+
+  const [emailError, setEmailError] = useState('');
+  const [passwordError, setPasswordError] = useState('');
 
   const {
     mutate: loginMutate,
@@ -84,52 +171,75 @@ export default function Login() {
       setIsPending(false);
       fireToast({ content: loginMutationError.message ?? '알 수 없는 오류가 발생했습니다.' });
     }
+    // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [fireToast, loginMutationError]);
 
-  return (
-    <>
-      <SEO title="로그인" />
-      <article css={loginCss}>
-        <div css={navMockupCss} />
-        <div css={loginIntroCardCss}></div>
+  return { handleFormSubmitEvent, email, password, emailError, passwordError };
+}
 
-        <form css={loginFieldSetCss} onSubmit={handleFormSubmitEvent}>
-          <TextField
-            type="email"
-            label={'이메일 아이디'}
-            placeholder={'이메일을 입력해주세요'}
-            feedback={email.debouncedValue !== '' ? emailError || <>&nbsp;</> : <>&nbsp;</>}
-            isSuccess={email.debouncedValue.length > 0 && emailError === ''}
-            value={email.value}
-            onChange={email.onChange}
-            required
-            alertWhenFocused
-          />
-          <TextField
-            type="password"
-            label={'비밀번호'}
-            placeholder={'영문, 숫자 포함 6자 이상의 비밀번호'}
-            feedback={password.debouncedValue !== '' ? passwordError || <>&nbsp;</> : <>&nbsp;</>}
-            isSuccess={password.debouncedValue.length > 0 && passwordError === ''}
-            value={password.value}
-            onChange={password.onChange}
-            required
-            alertWhenFocused
-          />
-          <CTAButton type={'submit'} disabled={isPending}>
-            로그인
-          </CTAButton>
-        </form>
-        <GhostButton onClick={() => push('/password')}>비밀번호 찾기</GhostButton>
-        <div css={signUpTextWrapperCss}>
-          계정이 없으신가요?{' '}
-          <GhostButton size={'small'} onClick={() => push('/signup')}>
-            빠르게 가입하기
-          </GhostButton>
-        </div>
-      </article>
-    </>
-  );
+function useExtensionAuth({ setIsPending }: { setIsPending: (value: boolean) => void }) {
+  const { getRedirect, goRedirect } = useLoginRedirect();
+  const { push } = useInternalRouter();
+  const { fireToast } = useToast();
+  const { userLogin } = useUser();
+  const [canExtensionLogin, setCanExtensionLogin] = useState(false);
+  const [userCancelExtensionLogin, setUserCancelExtensionLogin] = useState(false);
+
+  const { mutate: reissueMutate } = useReissueMutation({
+    onSuccess: ({ data }) => {
+      userLogin({
+        accessToken: data.accessToken,
+        refreshToken: data.refreshToken,
+      });
+      setIsPending(false);
+      recordEvent({ action: 'Login', value: '로그인 화면에서 익스텐션 계정으로 로그인' });
+
+      if (getRedirect()) {
+        goRedirect();
+      } else {
+        push('/');
+      }
+    },
+    onError: () => {
+      fireToast({ content: '익스텐션 계정으로 로그인하는데 실패했습니다.' });
+      setCanExtensionLogin(false);
+      setIsPending(false);
+    },
+  });
+
+  const handleExtensionLogin = () => {
+    setIsPending(true);
+    const token = localStorage.getItem(localStorageExtensionKeys.refreshToken);
+    if (token) {
+      reissueMutate({ refreshToken: token });
+    }
+  };
+
+  useEffect(() => {
+    const checkLoginAvailable = () => {
+      if (userCancelExtensionLogin) {
+        return;
+      }
+      if (localStorage.getItem(localStorageExtensionKeys.refreshToken)) {
+        setCanExtensionLogin(true);
+      } else {
+        setCanExtensionLogin(false);
+      }
+    };
+    checkLoginAvailable();
+    const interval = setInterval(checkLoginAvailable, 3000);
+    return () => {
+      clearInterval(interval);
+    };
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, []);
+
+  return {
+    canExtensionLogin,
+    handleExtensionLogin,
+    setUserCancelExtensionLogin,
+    userCancelExtensionLogin,
+  };
 }
 
 const navMockupCss = css`
@@ -166,3 +276,8 @@ const signUpTextWrapperCss = (theme: Theme) => css`
   font-size: 10px;
   line-height: 150%;
 `;
+
+const dialogLongButtonCss = css`
+  width: 160px;
+  flex-shrink: 0;
+`;