diff --git a/web/src/components/3d/ViewerPanel.test.tsx b/web/src/components/3d/ViewerPanel.test.tsx
index d9aaeb1d0..267cd2281 100644
--- a/web/src/components/3d/ViewerPanel.test.tsx
+++ b/web/src/components/3d/ViewerPanel.test.tsx
@@ -2,7 +2,7 @@ import { hydrateRoot } from 'react-dom/client';
 import { renderToString } from 'react-dom/server';
 import { act, render, screen } from '@testing-library/react';
 import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
-import { useAppStore } from '@/store/useAppStore';
+import { useAppStore, type HomeTabType } from '@/store/useAppStore';
 import ViewerPanel from './ViewerPanel';
 
 // The home page's 3D view is the build globe (hero, Inside) or the product
@@ -45,11 +45,12 @@ afterEach(() => {
   vi.useRealTimers();
 });
 
-// The tabs beside the view, which must outlive it.
-function Page() {
+// The tabs beside the view, which must outlive it. The page passes the tab
+// it was made for, as HomeView does.
+function Page({ tab = 'hero' }: { tab?: HomeTabType }) {
   return (
     <>
-      <ViewerPanel />
+      <ViewerPanel initialTab={tab} />
       <button type="button">Build</button>
     </>
   );
@@ -71,7 +72,7 @@ describe('ViewerPanel', () => {
     (tab) => {
       webgl.answer = false;
       useAppStore.setState({ homeTab: tab });
-      render(<Page />);
+      render(<Page tab={tab} />);
       expect(scenes.made).toEqual([]);
       expect(screen.getByText(LINE)).toBeInTheDocument();
       expect(screen.getByRole('button', { name: 'Build' })).toBeInTheDocument();
@@ -82,7 +83,7 @@ describe('ViewerPanel', () => {
     vi.spyOn(console, 'error').mockImplementation(() => {});
     scenes.throws.add('product');
     useAppStore.setState({ homeTab: 'pattern' });
-    render(<Page />);
+    render(<Page tab="pattern" />);
     expect(screen.queryByTestId('scene')).not.toBeInTheDocument();
     expect(screen.getByText(LINE)).toBeInTheDocument();
     expect(screen.getByRole('button', { name: 'Build' })).toBeInTheDocument();
@@ -92,7 +93,7 @@ describe('ViewerPanel', () => {
     vi.spyOn(console, 'error').mockImplementation(() => {});
     scenes.throws.add('product');
     useAppStore.setState({ homeTab: 'build' });
-    render(<Page />);
+    render(<Page tab="build" />);
     expect(screen.getByText(LINE)).toBeInTheDocument();
     act(() => useAppStore.setState({ homeTab: 'inside' }));
     act(() => vi.advanceTimersByTime(200));
@@ -100,9 +101,46 @@ describe('ViewerPanel', () => {
     expect(screen.queryByText(LINE)).not.toBeInTheDocument();
   });
 
-  it('sends the page as it was from the server, and the browser without WebGL takes it up without a mismatch', async () => {
+  // The store says hero until RightPanel's effect tells it otherwise. Read
+  // from it, /build opened on the globe and kept it through the fade: long
+  // enough to mount it and send for every pin's photos.
+  it.each(['build', 'pattern'] as const)('opens /%s on the product and never makes the globe', (tab) => {
+    render(<Page tab={tab} />);
+    expect(screen.getByTestId('scene')).toHaveTextContent('product');
+    // RightPanel's effect, telling the store the tab the page opened on.
+    act(() => useAppStore.getState().setHomeTab(tab));
+    act(() => vi.advanceTimersByTime(200));
+    expect(scenes.made).not.toContain('globe');
+    expect(screen.getByTestId('scene')).toHaveTextContent('product');
+  });
+
+  it('opens /pattern on the product when the store still holds Inside from an earlier visit', () => {
+    useAppStore.setState({ homeTab: 'inside' });
+    render(<Page tab="pattern" />);
+    act(() => useAppStore.getState().setHomeTab('pattern'));
+    act(() => vi.advanceTimersByTime(200));
+    expect(scenes.made).not.toContain('globe');
+  });
+
+  it('follows the store once it changes, from whichever tab the page opened on', () => {
+    render(<Page tab="build" />);
+    act(() => useAppStore.getState().setHomeTab('build'));
+    act(() => useAppStore.getState().setHomeTab('inside'));
+    act(() => vi.advanceTimersByTime(200));
+    expect(screen.getByTestId('scene')).toHaveTextContent('globe');
+    act(() => useAppStore.getState().setHomeTab('hero'));
+    expect(screen.getByTestId('scene')).toHaveTextContent('globe');
+  });
+
+  it('drops down on a phone from the first render of /build, as the panel beside it does', () => {
+    const html = renderToString(<Page tab="build" />);
+    expect(html).toContain('viewer-panel is-open');
+    expect(renderToString(<Page />)).not.toContain('is-open');
+  });
+
+  it.each(['hero', 'build'] as const)('sends %s as it was from the server, and the browser without WebGL takes it up without a mismatch', async (tab) => {
     webgl.answer = false;
-    const html = renderToString(<Page />);
+    const html = renderToString(<Page tab={tab} />);
     // The server cannot ask: it answers yes and never calls the probe.
     expect(webgl.asked).toBe(0);
     expect(html).not.toContain('draw the 3D view');
@@ -111,7 +149,7 @@ describe('ViewerPanel', () => {
     container.innerHTML = html;
     document.body.appendChild(container);
     const recoverable = vi.fn();
-    const root = await act(async () => hydrateRoot(container, <Page />, { onRecoverableError: recoverable }));
+    const root = await act(async () => hydrateRoot(container, <Page tab={tab} />, { onRecoverableError: recoverable }));
     expect(recoverable).not.toHaveBeenCalled();
     expect(container).toHaveTextContent(LINE);
     expect(container.querySelector('[data-testid="scene"]')).toBeNull();
diff --git a/web/src/components/3d/ViewerPanel.tsx b/web/src/components/3d/ViewerPanel.tsx
index 792880b17..56382336c 100644
--- a/web/src/components/3d/ViewerPanel.tsx
+++ b/web/src/components/3d/ViewerPanel.tsx
@@ -3,7 +3,7 @@
 import dynamic from 'next/dynamic';
 import { Component, useEffect, useState, useSyncExternalStore, type ReactNode } from 'react';
 import HeroScene from './HeroScene';
-import { useAppStore } from '@/store/useAppStore';
+import { useAppStore, type HomeTabType } from '@/store/useAppStore';
 import { hasWebGL } from '@/lib/webgl';
 
 // The hero and the Inside section show the build globe; Build and Pattern
@@ -41,8 +41,16 @@ class SceneGuard extends Component<{ children: ReactNode }, { failed: boolean }>
 // On desktop the panel is always shown (sticky left column). On mobile it stays
 // hidden while the hero is full-screen and only "drops down" once a section tab
 // (Build / Pattern / Inside) is opened from the bottom nav.
-export default function ViewerPanel() {
-  const homeTab = useAppStore((state) => state.homeTab);
+export default function ViewerPanel({ initialTab = 'hero' }: { initialTab?: HomeTabType }) {
+  // The store starts on the hero on every page and hears the page's tab from
+  // RightPanel's effect, after this panel has rendered once. Read from the
+  // store, /build and /pattern opened on the globe for the length of the
+  // fade, long enough to mount it and send for every pin's photos. So the
+  // panel starts on the tab the page was made for and follows the store from
+  // its first change. This effect runs before RightPanel's: siblings mount in
+  // order, and HomeView puts this panel first.
+  const [homeTab, setHomeTab] = useState(initialTab);
+  useEffect(() => useAppStore.subscribe((state) => setHomeTab(state.homeTab)), []);
   const isOpen = homeTab !== 'hero';
   // The server cannot ask for a context, so it answers yes and sends the page
   // as it was. The client asks while hydrating, before either scene's canvas
diff --git a/web/src/components/HomeView.tsx b/web/src/components/HomeView.tsx
index 9f031874f..bf1505a57 100644
--- a/web/src/components/HomeView.tsx
+++ b/web/src/components/HomeView.tsx
@@ -23,7 +23,7 @@ export default function HomeView({ initialTab = 'hero', initialBuildId = null }:
       <div className="mobile-page-links">
         <HeroJournalLink />
       </div>
-      <ViewerPanel />
+      <ViewerPanel initialTab={initialTab} />
       <RightPanel
         initialTab={initialTab}
         buildContent={buildContent}
diff --git a/web/src/components/sections/InsideGlobe/GlobeViewer.test.tsx b/web/src/components/sections/InsideGlobe/GlobeViewer.test.tsx
new file mode 100644
index 000000000..e2b870e0d
--- /dev/null
+++ b/web/src/components/sections/InsideGlobe/GlobeViewer.test.tsx
@@ -0,0 +1,54 @@
+import { act, render } from '@testing-library/react';
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+import { useAppStore } from '@/store/useAppStore';
+import { builds, CARD_TILES, STRIP_TILES } from './builds';
+import GlobeViewer from './GlobeViewer';
+
+// The globe warms each pin's opening photos so a pin opens with them. Below
+// 901px the 3D view is hidden on the hero, yet the globe there still sent for
+// every one of them, in the large variant a 3× phone picks: 65 photos and
+// 8.3 MB on 22 October, for a map nobody saw.
+
+vi.mock('./Globe', () => ({ default: () => <div data-testid="globe" /> }));
+
+const media = vi.hoisted(() => ({ wide: false }));
+const TILES = builds.flatMap((build) => (build.images ?? []).slice(0, Math.max(STRIP_TILES, CARD_TILES)));
+
+beforeEach(() => {
+  vi.stubGlobal('matchMedia', (query: string) => ({
+    media: query,
+    matches: query === '(min-width: 901px)' && media.wide,
+    addEventListener: () => {},
+    removeEventListener: () => {},
+  }));
+  useAppStore.setState({ homeTab: 'hero', selectedBuildId: null, insideFilter: 'all' });
+});
+
+afterEach(() => {
+  vi.unstubAllGlobals();
+});
+
+const warmed = (container: HTMLElement) => container.querySelectorAll('.preload img').length;
+
+describe('GlobeViewer', () => {
+  it('warms no photo for the hidden globe of a phone’s hero', () => {
+    media.wide = false;
+    const { container, getByTestId } = render(<GlobeViewer />);
+    expect(getByTestId('globe')).toBeInTheDocument();
+    expect(warmed(container)).toBe(0);
+  });
+
+  it('warms every pin’s opening photos once a phone opens Inside', () => {
+    media.wide = false;
+    const { container } = render(<GlobeViewer />);
+    act(() => useAppStore.getState().setHomeTab('inside'));
+    expect(TILES.length).toBeGreaterThan(0);
+    expect(warmed(container)).toBe(TILES.length);
+  });
+
+  it('warms them on the hero from 901px up, where the globe stands beside the page', () => {
+    media.wide = true;
+    const { container } = render(<GlobeViewer />);
+    expect(warmed(container)).toBe(TILES.length);
+  });
+});
diff --git a/web/src/components/sections/InsideGlobe/GlobeViewer.tsx b/web/src/components/sections/InsideGlobe/GlobeViewer.tsx
index 565c1518d..d3afc810c 100644
--- a/web/src/components/sections/InsideGlobe/GlobeViewer.tsx
+++ b/web/src/components/sections/InsideGlobe/GlobeViewer.tsx
@@ -9,6 +9,7 @@ import PinLink from './PinLink';
 import { builds, formatBuildDate, CARD_TILES, STRIP_TILES } from './builds';
 import { useBuildSelection } from './useBuildSelection';
 import { useAppStore } from '@/store/useAppStore';
+import { useMediaQuery } from '@/lib/hooks/useMediaQuery';
 import styles from './GlobeViewer.module.css';
 
 // The Inside section's viewer: an interactive globe with the picked build's
@@ -22,7 +23,15 @@ export default function GlobeViewer() {
   const { selectedId, select: selectBuild, visibleBuilds } = useBuildSelection();
   // On the hero the globe stands in for the product shot: no filters, and a
   // pin opens the Inside section rather than a detail card beside hero copy.
-  const onHero = useAppStore((state) => state.homeTab) === 'hero';
+  const homeTab = useAppStore((state) => state.homeTab);
+  const onHero = homeTab === 'hero';
+  // Below 901px the 3D view is hidden on the hero (globals.css) and drops
+  // down only for a tab, so a phone shows the globe on Inside alone. The
+  // photos below are warmed only where the globe is seen: a phone's hidden
+  // hero globe sent for all of them, in the large variant a 3× screen picks.
+  // The query reads false until measured, so a phone never renders them.
+  const wide = useMediaQuery('(min-width: 901px)');
+  const warm = wide || homeTab === 'inside';
   const [galleryIndex, setGalleryIndex] = useState<number | null>(null);
   const [hasSelected, setHasSelected] = useState(false);
 
@@ -70,17 +79,19 @@ export default function GlobeViewer() {
   return (
     <div className={styles.viewer}>
       {/* Offscreen preloader: fetch each pin's opening tiles (the same optimized
-          variant the strip and card use) eagerly the moment the globe mounts, so
+          variant the strip and card use) eagerly the moment the globe is seen, so
           opening a pin shows its photos instantly instead of lazy-loading. Low
           fetch priority so they queue behind the globe itself rather than
           competing with it for bandwidth on first paint. */}
-      <div className={styles.preload} aria-hidden>
-        {allImages.map((image) => (
-          <span key={image.src} className={styles.preloadBox}>
-            <Image src={image.src} alt="" fill sizes="280px" loading="eager" fetchPriority="low" />
-          </span>
-        ))}
-      </div>
+      {warm && (
+        <div className={styles.preload} aria-hidden>
+          {allImages.map((image) => (
+            <span key={image.src} className={styles.preloadBox}>
+              <Image src={image.src} alt="" fill sizes="280px" loading="eager" fetchPriority="low" />
+            </span>
+          ))}
+        </div>
+      )}
 
       <Globe entries={visibleBuilds} selectedBuildId={selectedId ?? undefined} onSelectBuild={select} />
       {!onHero && <BuildFilters />}