diff --git a/apps/web/src/browserHistoryStore.test.ts b/apps/web/src/browserHistoryStore.test.ts
index c68d3334b6f2..bc0aa9a29d25 100644
--- a/apps/web/src/browserHistoryStore.test.ts
+++ b/apps/web/src/browserHistoryStore.test.ts
@@ -2,7 +2,9 @@ import { afterEach, beforeEach, describe, expect, it, vi } from "vite-plus/test"
 
 import { scopeProjectRef } from "@t3tools/client-runtime/environment";
 import {
+  type BrowserProfileId,
   EnvironmentId,
+  INCOGNITO_BROWSER_PROFILE_ID,
   type PreviewSessionSnapshot,
   ProjectId,
   ThreadId,
@@ -157,7 +159,13 @@ const threadRef = {
 
 let settledAt = 0;
 
-function settle(url: string, title: string, tabId = "tab_a", ref = threadRef): void {
+function settle(
+  url: string,
+  title: string,
+  tabId = "tab_a",
+  ref = threadRef,
+  profileId?: BrowserProfileId,
+): void {
   settledAt += 1;
   const snapshot: PreviewSessionSnapshot = {
     threadId: ref.threadId,
@@ -166,6 +174,7 @@ function settle(url: string, title: string, tabId = "tab_a", ref = threadRef): v
     canGoBack: false,
     canGoForward: false,
     updatedAt: new Date(settledAt).toISOString(),
+    ...(profileId ? { profileId } : {}),
   };
   applyPreviewServerSnapshot(ref, snapshot);
 }
@@ -208,6 +217,17 @@ describe("useBrowserHistoryStore", () => {
     expect(useBrowserHistoryStore.getState().byProjectKey["proj-a"]?.[0]?.title).toBe("New");
   });
 
+  it("never titles history from an Incognito page, whichever settles first", () => {
+    useBrowserHistoryStore.getState().registerThreadProject(threadRef, "proj-a");
+    settle("http://a.test/", "Private A", "tab_incognito", threadRef, INCOGNITO_BROWSER_PROFILE_ID);
+    recordVisitForThread(threadRef, "http://a.test/", 1);
+    recordVisitForThread(threadRef, "http://b.test/", 2);
+    settle("http://b.test/", "Private B", "tab_incognito", threadRef, INCOGNITO_BROWSER_PROFILE_ID);
+    expect(
+      useBrowserHistoryStore.getState().byProjectKey["proj-a"]?.map((entry) => entry.title),
+    ).toEqual([undefined, undefined]);
+  });
+
   it("keeps another thread's newer title when an unrelated tab settles", () => {
     const otherThreadRef = { ...threadRef, threadId: ThreadId.make("thread-2") };
     const store = useBrowserHistoryStore.getState();
diff --git a/apps/web/src/browserHistoryStore.ts b/apps/web/src/browserHistoryStore.ts
index fe1982f742ea..d5ccb0fcd621 100644
--- a/apps/web/src/browserHistoryStore.ts
+++ b/apps/web/src/browserHistoryStore.ts
@@ -3,11 +3,12 @@ import {
   scopedThreadKey,
   scopeProjectRef,
 } from "@t3tools/client-runtime/environment";
-import type {
-  EnvironmentId,
-  PreviewSessionSnapshot,
-  ScopedProjectRef,
-  ScopedThreadRef,
+import {
+  type EnvironmentId,
+  INCOGNITO_BROWSER_PROFILE_ID,
+  type PreviewSessionSnapshot,
+  type ScopedProjectRef,
+  type ScopedThreadRef,
 } from "@t3tools/contracts";
 import { create } from "zustand";
 import { createJSONStorage, persist } from "zustand/middleware";
@@ -468,6 +469,7 @@ function recordPreviewTitles(
   );
   for (const session of sessions) {
     const status = session.navStatus;
+    if (session.profileId === INCOGNITO_BROWSER_PROFILE_ID) continue;
     if (status._tag !== "Success" || !status.title || !include(session, status.url)) continue;
     state.setTitleForUrl(projectKey, status.url, status.title, environmentHostname);
   }
diff --git a/apps/web/src/components/preview/PreviewView.tsx b/apps/web/src/components/preview/PreviewView.tsx
index 5629352f38c8..25ba198469ea 100644
--- a/apps/web/src/components/preview/PreviewView.tsx
+++ b/apps/web/src/components/preview/PreviewView.tsx
@@ -10,6 +10,7 @@ import {
 import {
   AuthOrchestrationOperateScope,
   DEFAULT_BROWSER_PROFILE_ID,
+  INCOGNITO_BROWSER_PROFILE_ID,
   FILL_PREVIEW_VIEWPORT,
   type PreviewAnnotationPayload,
   type ScopedThreadRef,
@@ -248,18 +249,19 @@ export function PreviewView({
     runtimeTabId ? (state.byTabId[runtimeTabId]?.rect ?? null) : null,
   );
 
+  /** Resolves to the profile of the tab that loaded the URL, or null when nothing opened. */
   const navigateToResolvedUrl = async (resolvedUrl: string) => {
     if (isServerTab && serverSurfaceRef.current) {
-      if (serverInputDisabled) return false;
+      if (serverInputDisabled) return null;
       serverSurfaceRef.current.navigate(resolvedUrl);
       rememberPreviewUrl(threadRef, resolvedUrl);
-      return true;
+      return activeProfileId;
     }
     if (runtimeTabId && previewBridge) {
       await previewBridge.navigate(runtimeTabId, resolvedUrl);
       rememberPreviewUrl(threadRef, resolvedUrl);
       focusPreviewPage(runtimeTabId);
-      return true;
+      return activeProfileId;
     }
     const result = await openPreviewSession({ openPreview: open, threadRef, url: resolvedUrl });
     if (result._tag === "Failure" && !isAtomCommandInterrupted(result)) {
@@ -272,13 +274,19 @@ export function PreviewView({
         });
       }
     }
-    return result._tag === "Success";
+    return result._tag === "Success"
+      ? (result.value.profileId ?? DEFAULT_BROWSER_PROFILE_ID)
+      : null;
   };
 
+  // Incognito visits stay out of the project's persisted history.
+  const isHistoryProfile = (profileId: string | null) =>
+    profileId !== null && profileId !== INCOGNITO_BROWSER_PROFILE_ID;
+
   const handleSubmitUrl = async (next: string) => {
     try {
       const resolved = resolveAddressBarInput(next, resolveSearchUrlTemplate(getClientSettings()));
-      if (await navigateToResolvedUrl(resolved)) {
+      if (isHistoryProfile(await navigateToResolvedUrl(resolved))) {
         recordVisitForThread(threadRef, resolved);
       }
     } catch (error) {
@@ -300,7 +308,7 @@ export function PreviewView({
         isServerTab || !previewBridge
           ? normalizePreviewUrl(next)
           : resolveDiscoveredServerUrl(threadRef.environmentId, next);
-      if (await navigateToResolvedUrl(resolved)) {
+      if (isHistoryProfile(await navigateToResolvedUrl(resolved))) {
         recordVisitForThread(threadRef, next);
       }
     } catch (error) {