diff --git a/src/components/dialog/content/SignInContent.vue b/src/components/dialog/content/SignInContent.vue
index 3f3a47b7b..29f441a28 100644
--- a/src/components/dialog/content/SignInContent.vue
+++ b/src/components/dialog/content/SignInContent.vue
@@ -45,37 +45,39 @@
         <span class="text-muted">{{ t('auth.login.orContinueWith') }}</span>
       </Divider>
 
-      <!-- Social Login Buttons -->
+      <!-- Social Login Buttons (hidden if host not whitelisted) -->
       <div class="flex flex-col gap-6">
-        <Button
-          type="button"
-          class="h-10"
-          severity="secondary"
-          outlined
-          @click="signInWithGoogle"
-        >
-          <i class="pi pi-google mr-2"></i>
-          {{
-            isSignIn
-              ? t('auth.login.loginWithGoogle')
-              : t('auth.signup.signUpWithGoogle')
-          }}
-        </Button>
+        <template v-if="ssoAllowed">
+          <Button
+            type="button"
+            class="h-10"
+            severity="secondary"
+            outlined
+            @click="signInWithGoogle"
+          >
+            <i class="pi pi-google mr-2"></i>
+            {{
+              isSignIn
+                ? t('auth.login.loginWithGoogle')
+                : t('auth.signup.signUpWithGoogle')
+            }}
+          </Button>
 
-        <Button
-          type="button"
-          class="h-10"
-          severity="secondary"
-          outlined
-          @click="signInWithGithub"
-        >
-          <i class="pi pi-github mr-2"></i>
-          {{
-            isSignIn
-              ? t('auth.login.loginWithGithub')
-              : t('auth.signup.signUpWithGithub')
-          }}
-        </Button>
+          <Button
+            type="button"
+            class="h-10"
+            severity="secondary"
+            outlined
+            @click="signInWithGithub"
+          >
+            <i class="pi pi-github mr-2"></i>
+            {{
+              isSignIn
+                ? t('auth.login.loginWithGithub')
+                : t('auth.signup.signUpWithGithub')
+            }}
+          </Button>
+        </template>
 
         <Button
           type="button"
@@ -149,6 +151,7 @@ import { useI18n } from 'vue-i18n'
 import { useFirebaseAuthActions } from '@/composables/auth/useFirebaseAuthActions'
 import { COMFY_PLATFORM_BASE_URL } from '@/config/comfyApi'
 import type { SignInData, SignUpData } from '@/schemas/signInSchema'
+import { isHostWhitelisted, normalizeHost } from '@/utils/hostWhitelist'
 import { isInChina } from '@/utils/networkUtil'
 
 import ApiKeyForm from './signin/ApiKeyForm.vue'
@@ -164,6 +167,7 @@ const authActions = useFirebaseAuthActions()
 const isSecureContext = window.isSecureContext
 const isSignIn = ref(true)
 const showApiKeyForm = ref(false)
+const ssoAllowed = isHostWhitelisted(normalizeHost(window.location.hostname))
 
 const toggleState = () => {
   isSignIn.value = !isSignIn.value
diff --git a/src/utils/hostWhitelist.ts b/src/utils/hostWhitelist.ts
new file mode 100644
index 000000000..3fb1ae2c3
--- /dev/null
+++ b/src/utils/hostWhitelist.ts
@@ -0,0 +1,91 @@
+/**
+ * Whitelisting helper for enabling SSO on safe, local-only hosts.
+ *
+ * Built-ins (always allowed):
+ *   • 'localhost' and any subdomain of '.localhost' (e.g., app.localhost)
+ *   • IPv4 loopback 127.0.0.0/8 (e.g., 127.0.0.1, 127.1.2.3)
+ *   • IPv6 loopback ::1 (supports compressed/expanded textual forms)
+ *
+ * No environment variables are used. To add more exact hostnames,
+ * edit HOST_WHITELIST below.
+ */
+
+const HOST_WHITELIST: string[] = ['localhost']
+
+/** Normalize for comparison: lowercase, strip port/brackets, trim trailing dot. */
+export function normalizeHost(input: string): string {
+  let h = (input || '').trim().toLowerCase()
+
+  // Trim a trailing dot: 'localhost.' -> 'localhost'
+  h = h.replace(/\.$/, '')
+
+  // Remove ':port' safely.
+  // Case 1: [IPv6]:port
+  const mBracket = h.match(/^\[([^\]]+)\]:(\d+)$/)
+  if (mBracket) {
+    h = mBracket[1] // keep only the host inside the brackets
+  } else {
+    // Case 2: hostname/IPv4:port (exactly one ':')
+    const mPort = h.match(/^([^:]+):(\d+)$/)
+    if (mPort) h = mPort[1]
+  }
+
+  // Strip any remaining brackets (e.g., '[::1]' -> '::1')
+  h = h.replace(/^\[|\]$/g, '')
+
+  return h
+}
+
+/** Public check used by the UI. */
+export function isHostWhitelisted(rawHost: string): boolean {
+  const host = normalizeHost(rawHost)
+  if (isLocalhostLabel(host)) return true
+  if (isIPv4Loopback(host)) return true
+  if (isIPv6Loopback(host)) return true
+  const normalizedList = HOST_WHITELIST.map(normalizeHost)
+  return normalizedList.includes(host)
+}
+
+/* -------------------- Helpers -------------------- */
+
+function isLocalhostLabel(h: string): boolean {
+  // 'localhost' and any subdomain (e.g., 'app.localhost')
+  return h === 'localhost' || h.endsWith('.localhost')
+}
+
+const IPV4_OCTET = '(?:25[0-5]|2[0-4]\\d|1\\d\\d|0?\\d?\\d)'
+const V4_LOOPBACK_RE = new RegExp(
+  '^127\\.' + IPV4_OCTET + '\\.' + IPV4_OCTET + '\\.' + IPV4_OCTET + '$'
+)
+
+function isIPv4Loopback(h: string): boolean {
+  // 127/8 with strict 0–255 octets (leading zeros allowed, e.g., 127.000.000.001)
+  return V4_LOOPBACK_RE.test(h)
+}
+
+// Fully expanded IPv6 loopback: 0:0:0:0:0:0:0:1 (allow leading zeros up to 4 chars)
+const V6_FULL_LOOPBACK_RE = /^(?:0{1,4}:){7}0{0,3}1$/i
+
+// Compressed IPv6 loopback forms around '::' with only zero groups before the final :1
+// - Left side: zero groups separated by ':' (no trailing colon required)
+// - Right side: zero groups each followed by ':' (so the final ':1' is provided by the pattern)
+// The final group is exactly value 1, with up to 3 leading zeros (e.g., '0001').
+const V6_COMPRESSED_LOOPBACK_RE =
+  /^((?:0{1,4}(?::0{1,4}){0,6})?)::((?:0{1,4}:){0,6})0{0,3}1$/i
+
+function isIPv6Loopback(h: string): boolean {
+  // Exact full form: 0:0:0:0:0:0:0:1 (with up to 3 leading zeros on the final "1" group)
+  if (V6_FULL_LOOPBACK_RE.test(h)) return true
+
+  // Compressed forms that still equal ::1 (e.g., ::1, ::0001, 0:0::1, ::0:1, etc.)
+  const m = h.match(V6_COMPRESSED_LOOPBACK_RE)
+  if (!m) return false
+
+  // Count explicit zero groups on each side of '::' to ensure at least one group is compressed.
+  // (leftCount + rightCount) must be ≤ 6 so that the total expanded groups = 8.
+  const leftCount = m[1] ? m[1].match(/0{1,4}:/gi)?.length ?? 0 : 0
+  const rightCount = m[2] ? m[2].match(/0{1,4}:/gi)?.length ?? 0 : 0
+
+  // Require that at least one group was actually compressed: i.e., leftCount + rightCount ≤ 6.
+  return leftCount + rightCount <= 6
+}
diff --git a/tests-ui/tests/utils/hostWhitelist.test.ts b/tests-ui/tests/utils/hostWhitelist.test.ts
new file mode 100644
index 000000000..cd3506dff
--- /dev/null
+++ b/tests-ui/tests/utils/hostWhitelist.test.ts
@@ -0,0 +1,123 @@
+import { describe, expect, it } from 'vitest'
+
+import { isHostWhitelisted, normalizeHost } from '@/utils/hostWhitelist'
+
+describe('hostWhitelist utils', () => {
+  describe('normalizeHost', () => {
+    it.each([
+      ['LOCALHOST', 'localhost'],
+      ['localhost.', 'localhost'], // trims trailing dot
+      ['localhost:5173', 'localhost'], // strips :port
+      ['127.0.0.1:5173', '127.0.0.1'], // strips :port
+      ['[::1]:5173', '::1'], // strips brackets + :port
+      ['[::1]', '::1'], // strips brackets
+      ['::1', '::1'], // leaves plain IPv6
+      ['  [::1]  ', '::1'], // trims whitespace
+      ['APP.LOCALHOST', 'app.localhost'], // lowercases
+      ['example.com.', 'example.com'], // trims trailing dot
+      ['[2001:db8::1]:8443', '2001:db8::1'], // IPv6 with brackets+port
+      ['2001:db8::1', '2001:db8::1'] // plain IPv6 stays
+    ])('normalizeHost(%o) -> %o', (input, expected) => {
+      expect(normalizeHost(input)).toBe(expected)
+    })
+
+    it('does not strip non-numeric suffixes (not a port pattern)', () => {
+      expect(normalizeHost('example.com:abc')).toBe('example.com:abc')
+      expect(normalizeHost('127.0.0.1:abc')).toBe('127.0.0.1:abc')
+    })
+  })
+
+  describe('isHostWhitelisted', () => {
+    describe('localhost label', () => {
+      it.each([
+        'localhost',
+        'LOCALHOST',
+        'localhost.',
+        'localhost:5173',
+        'foo.localhost',
+        'Foo.Localhost',
+        'sub.foo.localhost',
+        'foo.localhost:5173'
+      ])('should allow %o', (input) => {
+        expect(isHostWhitelisted(input)).toBe(true)
+      })
+
+      it.each([
+        'localhost.com',
+        'evil-localhost',
+        'notlocalhost',
+        'foo.localhost.evil'
+      ])('should NOT allow %o', (input) => {
+        expect(isHostWhitelisted(input)).toBe(false)
+      })
+    })
+
+    describe('IPv4 127/8 loopback', () => {
+      it.each([
+        '127.0.0.1',
+        '127.1.2.3',
+        '127.255.255.255',
+        '127.0.0.1:3000',
+        '127.000.000.001', // leading zeros are still digits 0-255
+        '127.0.0.1.' // trailing dot should be tolerated
+      ])('should allow %o', (input) => {
+        expect(isHostWhitelisted(input)).toBe(true)
+      })
+
+      it.each([
+        '126.0.0.1',
+        '127.256.0.1',
+        '127.-1.0.1',
+        '127.0.0.1:abc',
+        '128.0.0.1',
+        '192.168.1.10',
+        '10.0.0.2',
+        '0.0.0.0',
+        '255.255.255.255',
+        '127.0.0', // malformed
+        '127.0.0.1.5' // malformed
+      ])('should NOT allow %o', (input) => {
+        expect(isHostWhitelisted(input)).toBe(false)
+      })
+    })
+
+    describe('IPv6 loopback ::1 (all textual forms)', () => {
+      it.each([
+        '::1',
+        '[::1]',
+        '[::1]:5173',
+        '::0001',
+        '0:0:0:0:0:0:0:1',
+        '0000:0000:0000:0000:0000:0000:0000:0001',
+        // Compressed equivalents of ::1 (with zeros compressed)
+        '0:0::1',
+        '0:0:0:0:0:0::1',
+        '::0:1' // compressing the initial zeros (still ::1 when expanded)
+      ])('should allow %o', (input) => {
+        expect(isHostWhitelisted(input)).toBe(true)
+      })
+
+      it.each([
+        '::2',
+        '::',
+        '::0',
+        '0:0:0:0:0:0:0:2',
+        'fe80::1', // link-local, not loopback
+        '2001:db8::1',
+        '::1:5173', // bracketless "port-like" suffix must not pass
+        ':::1', // invalid (triple colon)
+        '0:0:0:0:0:0:::1', // invalid compression
+        '[::1%25lo0]',
+        '[::1%25lo0]:5173',
+        '::1%25lo0'
+      ])('should NOT allow %o', (input) => {
+        expect(isHostWhitelisted(input)).toBe(false)
+      })
+
+      it('should reject empty/whitespace-only input', () => {
+        expect(isHostWhitelisted('')).toBe(false)
+        expect(isHostWhitelisted('   ')).toBe(false)
+      })
+    })
+  })
+})