diff --git a/apps/sim/app/(auth)/signup/complete/page.tsx b/apps/sim/app/(auth)/signup/complete/page.tsx
new file mode 100644
index 00000000000..7195e84c65a
--- /dev/null
+++ b/apps/sim/app/(auth)/signup/complete/page.tsx
@@ -0,0 +1,16 @@
+import type { Metadata } from 'next'
+import { Suspense } from 'react'
+import { isHosted } from '@/lib/core/config/env-flags'
+import { SocialSignUpCompletion } from '@/app/(auth)/signup/complete/social-sign-up-completion'
+
+export const metadata: Metadata = {
+  title: 'Finishing Sign Up',
+}
+
+export default function SocialSignUpCompletePage() {
+  return (
+    <Suspense fallback={null}>
+      <SocialSignUpCompletion consentRequired={isHosted} />
+    </Suspense>
+  )
+}
diff --git a/apps/sim/app/(auth)/signup/complete/social-sign-up-completion.tsx b/apps/sim/app/(auth)/signup/complete/social-sign-up-completion.tsx
new file mode 100644
index 00000000000..1c98bb18e03
--- /dev/null
+++ b/apps/sim/app/(auth)/signup/complete/social-sign-up-completion.tsx
@@ -0,0 +1,62 @@
+'use client'
+
+import { useEffect, useRef } from 'react'
+import { useSearchParams } from 'next/navigation'
+import { useSession } from '@/lib/auth/client'
+import type { SocialSignInProvider } from '@/lib/auth/social-sign-in'
+import { trackSignUpCompletionConversions } from '@/lib/auth/social-sign-up-conversion'
+import { useTrackingConsent } from '@/lib/consent/tracking-consent'
+import { validateCallbackUrl } from '@/lib/core/security/input-validation'
+import { DEFAULT_POST_AUTH_ROUTE } from '@/app/(auth)/auth-redirect'
+
+interface SocialSignUpCompletionProps {
+  consentRequired: boolean
+}
+
+function isSignUpConversionMethod(value: string | null): value is SocialSignInProvider | 'email' {
+  return value === 'email' || value === 'github' || value === 'google' || value === 'microsoft'
+}
+
+export function SocialSignUpCompletion({ consentRequired }: SocialSignUpCompletionProps) {
+  const redirectStartedRef = useRef(false)
+  const searchParams = useSearchParams()
+  const { data: session, isPending } = useSession()
+  const { isResolved, measurement, marketing } = useTrackingConsent()
+  const callbackURL = searchParams.get('callbackURL')
+  const destination =
+    callbackURL && validateCallbackUrl(callbackURL) ? callbackURL : DEFAULT_POST_AUTH_ROUTE
+  const marker = searchParams.get('conversion')
+  const provider = searchParams.get('provider')
+
+  useEffect(() => {
+    if (redirectStartedRef.current || isPending || (consentRequired && !isResolved)) return
+    redirectStartedRef.current = true
+
+    const finishSignUp = async () => {
+      if (session?.user && isSignUpConversionMethod(provider)) {
+        await trackSignUpCompletionConversions({
+          marker,
+          method: provider,
+          userId: session.user.id,
+          measurement: consentRequired && measurement,
+          marketing: consentRequired && marketing,
+        })
+      }
+      window.location.href = destination
+    }
+
+    void finishSignUp()
+  }, [
+    consentRequired,
+    destination,
+    isPending,
+    isResolved,
+    marker,
+    measurement,
+    marketing,
+    provider,
+    session,
+  ])
+
+  return <p className='text-center text-[var(--text-secondary)] text-sm'>Finishing signup…</p>
+}
diff --git a/apps/sim/app/(auth)/signup/layout.tsx b/apps/sim/app/(auth)/signup/layout.tsx
new file mode 100644
index 00000000000..e7ca9492383
--- /dev/null
+++ b/apps/sim/app/(auth)/signup/layout.tsx
@@ -0,0 +1,16 @@
+import type { ReactNode } from 'react'
+import { isHosted } from '@/lib/core/config/env-flags'
+import { SignupConsentTracking } from '@/app/(auth)/signup/signup-consent-tracking'
+
+interface SignupLayoutProps {
+  children: ReactNode
+}
+
+export default function SignupLayout({ children }: SignupLayoutProps) {
+  return (
+    <>
+      {children}
+      {isHosted && <SignupConsentTracking />}
+    </>
+  )
+}
diff --git a/apps/sim/app/(auth)/signup/signup-consent-tracking.tsx b/apps/sim/app/(auth)/signup/signup-consent-tracking.tsx
new file mode 100644
index 00000000000..0d0697181d0
--- /dev/null
+++ b/apps/sim/app/(auth)/signup/signup-consent-tracking.tsx
@@ -0,0 +1,9 @@
+'use client'
+
+import { useConsentScript } from '@c15t/nextjs/headless'
+import { X_PIXEL_SCRIPT } from '@/lib/consent/scripts'
+
+export function SignupConsentTracking() {
+  useConsentScript({ script: X_PIXEL_SCRIPT, unmountBehavior: 'keep' })
+  return null
+}
diff --git a/apps/sim/app/(auth)/signup/signup-form.tsx b/apps/sim/app/(auth)/signup/signup-form.tsx
index 8eedc7f0d91..fa30df3c98e 100644
--- a/apps/sim/app/(auth)/signup/signup-form.tsx
+++ b/apps/sim/app/(auth)/signup/signup-form.tsx
@@ -5,9 +5,9 @@ import { Turnstile, type TurnstileInstance } from '@marsidev/react-turnstile'
 import { createLogger } from '@sim/logger'
 import { useRouter, useSearchParams } from 'next/navigation'
 import { usePostHog } from 'posthog-js/react'
-import { trackFreebuffConversion } from '@/lib/analytics/freebuff'
-import { trackGoogleEvent } from '@/lib/analytics/google'
+import { trackSignUpConversions } from '@/lib/analytics/sign-up'
 import { client, useSession } from '@/lib/auth/client'
+import { createEmailSignUpCallbackURL } from '@/lib/auth/social-sign-up-conversion'
 import { useTrackingConsent } from '@/lib/consent/tracking-consent'
 import { getEnv, isFalsy } from '@/lib/core/config/env'
 import { isSsoEnabled } from '@/lib/core/config/env-flags'
@@ -347,8 +347,18 @@ function SignupFormContent({
         return
       }
 
-      if (measurement) trackGoogleEvent('sign_up', { method: 'email' })
-      if (marketing) trackFreebuffConversion('signup_completed', response.data.user.id)
+      const destination = resolvePostSignupDestination({ emailVerificationEnabled, redirectUrl })
+
+      // Verification-enabled duplicate signups return synthetic success, so those conversions
+      // wait until the OTP-created session matches the user ID returned here.
+      if (!emailVerificationEnabled) {
+        await trackSignUpConversions({
+          method: 'email',
+          userId: response.data.user.id,
+          measurement,
+          marketing,
+        })
+      }
 
       try {
         await refetchSession()
@@ -357,8 +367,6 @@ function SignupFormContent({
         logger.error('Failed to refresh session after signup:', sessionError)
       }
 
-      const destination = resolvePostSignupDestination({ emailVerificationEnabled, redirectUrl })
-
       if (typeof window !== 'undefined') {
         // Clear any leftover from an earlier signup in this tab — otherwise a
         // signup with no callbackUrl inherits the previous CLI/invite destination.
@@ -366,8 +374,12 @@ function SignupFormContent({
         sessionStorage.removeItem(POST_AUTH_REDIRECT_STORAGE_KEY)
 
         if (destination.kind === 'verify') {
+          const postVerificationDestination = redirectUrl || DEFAULT_POST_AUTH_ROUTE
           sessionStorage.setItem('verificationEmail', emailValue)
-          if (redirectUrl) sessionStorage.setItem(POST_AUTH_REDIRECT_STORAGE_KEY, redirectUrl)
+          sessionStorage.setItem(
+            POST_AUTH_REDIRECT_STORAGE_KEY,
+            createEmailSignUpCallbackURL(response.data.user.id, postVerificationDestination)
+          )
         }
       }
 
diff --git a/apps/sim/lib/analytics/sign-up.test.ts b/apps/sim/lib/analytics/sign-up.test.ts
new file mode 100644
index 00000000000..e787ecf21cf
--- /dev/null
+++ b/apps/sim/lib/analytics/sign-up.test.ts
@@ -0,0 +1,43 @@
+/**
+ * @vitest-environment jsdom
+ * @vitest-environment-options {"url":"https://www.sim.ai/signup"}
+ */
+import { afterEach, describe, expect, it, vi } from 'vitest'
+import { trackSignUpConversions } from '@/lib/analytics/sign-up'
+
+afterEach(() => {
+  Reflect.deleteProperty(window, 'twq')
+  Reflect.deleteProperty(window, 'freebuff')
+  Reflect.deleteProperty(window, 'gtag')
+})
+
+describe('email signup conversions', () => {
+  it('reports the X signup event when marketing consent is granted', async () => {
+    const trackXEvent = vi.fn()
+    window.twq = trackXEvent
+
+    await trackSignUpConversions({
+      method: 'email',
+      userId: 'user-1',
+      measurement: false,
+      marketing: true,
+    })
+
+    expect(trackXEvent).toHaveBeenCalledOnce()
+    expect(trackXEvent).toHaveBeenCalledWith('event', 'tw-q5xbl-rhis8', {})
+  })
+
+  it('does not report the X signup event without marketing consent', async () => {
+    const trackXEvent = vi.fn()
+    window.twq = trackXEvent
+
+    await trackSignUpConversions({
+      method: 'email',
+      userId: 'user-1',
+      measurement: true,
+      marketing: false,
+    })
+
+    expect(trackXEvent).not.toHaveBeenCalled()
+  })
+})
diff --git a/apps/sim/lib/analytics/sign-up.ts b/apps/sim/lib/analytics/sign-up.ts
new file mode 100644
index 00000000000..5c7e02ce483
--- /dev/null
+++ b/apps/sim/lib/analytics/sign-up.ts
@@ -0,0 +1,38 @@
+import { sleep } from '@sim/utils/helpers'
+import { trackFreebuffConversion } from '@/lib/analytics/freebuff'
+import { trackGoogleEvent } from '@/lib/analytics/google'
+import { X_SIGN_UP_EVENT_ID } from '@/lib/consent/scripts'
+
+const X_PIXEL_STUB_WAIT_INTERVAL_MS = 50
+const X_PIXEL_STUB_WAIT_ATTEMPTS = 20
+
+interface TrackSignUpConversionsOptions {
+  method: string
+  userId: string
+  measurement: boolean
+  marketing: boolean
+}
+
+async function trackXSignUpConversion(): Promise<void> {
+  for (let attempt = 0; attempt < X_PIXEL_STUB_WAIT_ATTEMPTS; attempt += 1) {
+    if (typeof window.twq === 'function') {
+      window.twq('event', X_SIGN_UP_EVENT_ID, {})
+      return
+    }
+    await sleep(X_PIXEL_STUB_WAIT_INTERVAL_MS)
+  }
+}
+
+/** Reports a completed signup only to vendors allowed by the settled consent state. */
+export async function trackSignUpConversions({
+  method,
+  userId,
+  measurement,
+  marketing,
+}: TrackSignUpConversionsOptions): Promise<void> {
+  if (measurement) trackGoogleEvent('sign_up', { method })
+  if (!marketing) return
+
+  trackFreebuffConversion('signup_completed', userId)
+  await trackXSignUpConversion()
+}
diff --git a/apps/sim/lib/auth/social-sign-in.ts b/apps/sim/lib/auth/social-sign-in.ts
index dd146ab9912..9a96fde15ee 100644
--- a/apps/sim/lib/auth/social-sign-in.ts
+++ b/apps/sim/lib/auth/social-sign-in.ts
@@ -1,4 +1,5 @@
 import { client } from '@/lib/auth/client'
+import { createSocialSignUpCallbackURL } from '@/lib/auth/social-sign-up-conversion'
 import { captureClientEvent } from '@/lib/posthog/client'
 import type { PostHogEventMap } from '@/lib/posthog/events'
 
@@ -25,5 +26,9 @@ export function startSocialSignIn({
   callbackURL,
 }: StartSocialSignInOptions) {
   captureClientEvent('external_sign_in_started', { provider, view, surface })
-  return client.signIn.social({ provider, callbackURL })
+  return client.signIn.social({
+    provider,
+    callbackURL,
+    newUserCallbackURL: createSocialSignUpCallbackURL(provider, callbackURL),
+  })
 }
diff --git a/apps/sim/lib/auth/social-sign-up-conversion.test.ts b/apps/sim/lib/auth/social-sign-up-conversion.test.ts
new file mode 100644
index 00000000000..c08707620b6
--- /dev/null
+++ b/apps/sim/lib/auth/social-sign-up-conversion.test.ts
@@ -0,0 +1,93 @@
+/**
+ * @vitest-environment jsdom
+ * @vitest-environment-options {"url":"https://www.sim.ai/signup"}
+ */
+import { afterEach, describe, expect, it, vi } from 'vitest'
+import {
+  createEmailSignUpCallbackURL,
+  createSocialSignUpCallbackURL,
+  trackSignUpCompletionConversions,
+} from '@/lib/auth/social-sign-up-conversion'
+
+afterEach(() => {
+  sessionStorage.clear()
+  Reflect.deleteProperty(window, 'twq')
+  Reflect.deleteProperty(window, 'freebuff')
+  Reflect.deleteProperty(window, 'gtag')
+})
+
+function getConversionMarker(callbackURL: string): string {
+  return new URL(callbackURL, window.location.origin).searchParams.get('conversion') ?? ''
+}
+
+describe('signup completion conversions', () => {
+  it('reports a new social user once', async () => {
+    vi.stubEnv('NODE_ENV', 'production')
+    const trackXEvent = vi.fn()
+    const trackGoogleEvent = vi.fn()
+    const trackFreebuffEvent = vi.fn()
+    window.twq = trackXEvent
+    window.gtag = trackGoogleEvent
+    window.freebuff = trackFreebuffEvent
+    const marker = getConversionMarker(createSocialSignUpCallbackURL('google', '/workspace'))
+
+    const firstReport = await trackSignUpCompletionConversions({
+      marker,
+      method: 'google',
+      userId: 'user-1',
+      measurement: true,
+      marketing: true,
+    })
+    const duplicateReport = await trackSignUpCompletionConversions({
+      marker,
+      method: 'google',
+      userId: 'user-1',
+      measurement: true,
+      marketing: true,
+    })
+
+    expect(firstReport).toBe(true)
+    expect(duplicateReport).toBe(false)
+    expect(trackXEvent).toHaveBeenCalledOnce()
+    expect(trackGoogleEvent).toHaveBeenCalledWith(
+      'event',
+      'sign_up',
+      expect.objectContaining({ method: 'google' })
+    )
+    expect(trackFreebuffEvent).toHaveBeenCalledOnce()
+  })
+
+  it('does not report a returning social login that lacks the new-user callback marker', async () => {
+    const trackXEvent = vi.fn()
+    window.twq = trackXEvent
+    createSocialSignUpCallbackURL('github', '/workspace')
+
+    const reported = await trackSignUpCompletionConversions({
+      marker: 'not-the-pending-new-user-marker',
+      method: 'github',
+      userId: 'user-1',
+      measurement: true,
+      marketing: true,
+    })
+
+    expect(reported).toBe(false)
+    expect(trackXEvent).not.toHaveBeenCalled()
+  })
+
+  it('does not report a duplicate email signup with a synthetic user ID', async () => {
+    const trackXEvent = vi.fn()
+    window.twq = trackXEvent
+    const marker = getConversionMarker(createEmailSignUpCallbackURL('synthetic-user', '/workspace'))
+
+    const reported = await trackSignUpCompletionConversions({
+      marker,
+      method: 'email',
+      userId: 'existing-user',
+      measurement: true,
+      marketing: true,
+    })
+
+    expect(reported).toBe(false)
+    expect(trackXEvent).not.toHaveBeenCalled()
+  })
+})
diff --git a/apps/sim/lib/auth/social-sign-up-conversion.ts b/apps/sim/lib/auth/social-sign-up-conversion.ts
new file mode 100644
index 00000000000..e7f89d2555c
--- /dev/null
+++ b/apps/sim/lib/auth/social-sign-up-conversion.ts
@@ -0,0 +1,78 @@
+import { generateShortId } from '@sim/utils/id'
+import { trackSignUpConversions } from '@/lib/analytics/sign-up'
+import type { SocialSignInProvider } from '@/lib/auth/social-sign-in'
+
+const SIGN_UP_MARKER_STORAGE_KEY = 'socialSignUpConversionMarker'
+
+type SignUpConversionMethod = SocialSignInProvider | 'email'
+
+interface SignUpCompletionConversionOptions {
+  marker: string | null
+  method: SignUpConversionMethod
+  userId: string
+  measurement: boolean
+  marketing: boolean
+}
+
+function createSignUpCallbackURL(
+  method: SignUpConversionMethod,
+  callbackURL: string,
+  expectedUserId?: string
+): string {
+  const marker = generateShortId()
+  try {
+    const storedMarker = expectedUserId ? `${marker}:${expectedUserId}` : marker
+    sessionStorage.setItem(SIGN_UP_MARKER_STORAGE_KEY, storedMarker)
+  } catch {}
+
+  const params = new URLSearchParams({
+    provider: method,
+    callbackURL,
+    conversion: marker,
+  })
+  return `/signup/complete?${params.toString()}`
+}
+
+/** Creates Better Auth's new-user-only destination and remembers this browser initiated it. */
+export function createSocialSignUpCallbackURL(
+  provider: SocialSignInProvider,
+  callbackURL: string
+): string {
+  return createSignUpCallbackURL(provider, callbackURL)
+}
+
+/** Defers email conversion reporting until verification proves the returned user is real. */
+export function createEmailSignUpCallbackURL(userId: string, callbackURL: string): string {
+  return createSignUpCallbackURL('email', callbackURL, userId)
+}
+
+function claimSignUpMarker(marker: string | null, userId: string): boolean {
+  if (!marker) return false
+
+  try {
+    const storedMarker = sessionStorage.getItem(SIGN_UP_MARKER_STORAGE_KEY)
+    if (!storedMarker) return false
+
+    const [pendingMarker, expectedUserId] = storedMarker.split(':', 2)
+    if (pendingMarker !== marker) return false
+
+    sessionStorage.removeItem(SIGN_UP_MARKER_STORAGE_KEY)
+    return !expectedUserId || expectedUserId === userId
+  } catch {
+    return false
+  }
+}
+
+/** Claims a new-user marker before reporting so reloads and remounts cannot duplicate the signup. */
+export async function trackSignUpCompletionConversions({
+  marker,
+  method,
+  userId,
+  measurement,
+  marketing,
+}: SignUpCompletionConversionOptions): Promise<boolean> {
+  if (!claimSignUpMarker(marker, userId)) return false
+
+  await trackSignUpConversions({ method, userId, measurement, marketing })
+  return true
+}
diff --git a/apps/sim/lib/consent/scripts.ts b/apps/sim/lib/consent/scripts.ts
index c84a73391b7..24d78989e8c 100644
--- a/apps/sim/lib/consent/scripts.ts
+++ b/apps/sim/lib/consent/scripts.ts
@@ -22,6 +22,7 @@ export const GOOGLE_ANALYTICS_ID = 'G-QB9D67TBHR' as const
 export const GOOGLE_ADS_ID = 'AW-17916292239' as const
 export const X_PIXEL_ID = 'q5xbl' as const
 export const X_DEMO_BOOKED_EVENT_ID = 'tw-q5xbl-q5xbn' as const
+export const X_SIGN_UP_EVENT_ID = 'tw-q5xbl-rhis8' as const
 
 const AHREFS_ANALYTICS_KEY = 'WJ9yWTBAiQKZAE/2TyU/yA' as const