diff --git a/frontend/src/components/BrowserPanel.tsx b/frontend/src/components/BrowserPanel.tsx
new file mode 100644
index 0000000..0fd1b63
--- /dev/null
+++ b/frontend/src/components/BrowserPanel.tsx
@@ -0,0 +1,49 @@
+// BrowserPanel renders a noVNC iframe for viewing the live Playwright browser.
+//
+// URL detection strategy:
+//   - Production (cloudflared): When hostname is "research.ampbox.io", use the
+//     dedicated noVNC HTTPS endpoint at vnc.ampbox.io (routed via cloudflared tunnel).
+//   - Local dev (Docker): For any other hostname (e.g. localhost, 192.168.x.x),
+//     connect directly to the noVNC container on port 6080 over plain HTTP.
+
+export interface BrowserPanelProps {
+  sessionId: string | null
+}
+
+function getVncUrl(): string {
+  const hostname = window.location.hostname
+  if (hostname === 'research.ampbox.io') {
+    return 'https://vnc.ampbox.io/vnc.html?autoconnect=true&resize=remote&quality=6&compression=2'
+  }
+  return `http://${hostname}:6080/vnc.html?autoconnect=true&resize=remote&quality=6&compression=2`
+}
+
+export function BrowserPanel({ sessionId }: BrowserPanelProps) {
+  if (!sessionId) {
+    return (
+      <div
+        style={{
+          padding: '2rem',
+          color: '#6a6a8a',
+          textAlign: 'center',
+        }}
+      >
+        Select a session to view the browser
+      </div>
+    )
+  }
+
+  return (
+    <iframe
+      src={getVncUrl()}
+      title="Browser - noVNC"
+      style={{
+        width: '100%',
+        height: '100%',
+        border: 'none',
+        background: '#0a0a1a',
+      }}
+      allow="clipboard-read; clipboard-write"
+    />
+  )
+}
diff --git a/frontend/src/test/BrowserPanel.test.tsx b/frontend/src/test/BrowserPanel.test.tsx
new file mode 100644
index 0000000..41a4d1d
--- /dev/null
+++ b/frontend/src/test/BrowserPanel.test.tsx
@@ -0,0 +1,170 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest'
+import { render, screen } from '@testing-library/react'
+import { BrowserPanel } from '../components/BrowserPanel'
+
+describe('BrowserPanel', () => {
+  const originalLocation = window.location
+
+  beforeEach(() => {
+    // Reset location before each test
+    Object.defineProperty(window, 'location', {
+      configurable: true,
+      writable: true,
+      value: { hostname: 'localhost' },
+    })
+  })
+
+  afterEach(() => {
+    Object.defineProperty(window, 'location', {
+      configurable: true,
+      writable: true,
+      value: originalLocation,
+    })
+  })
+
+  describe('placeholder (no sessionId)', () => {
+    it('renders placeholder text when sessionId is null', () => {
+      render(<BrowserPanel sessionId={null} />)
+      expect(screen.getByText('Select a session to view the browser')).toBeTruthy()
+    })
+
+    it('does not render an iframe when sessionId is null', () => {
+      const { container } = render(<BrowserPanel sessionId={null} />)
+      expect(container.querySelector('iframe')).toBeNull()
+    })
+
+    it('placeholder div has padding 2rem', () => {
+      const { container } = render(<BrowserPanel sessionId={null} />)
+      const div = container.firstElementChild as HTMLElement
+      expect(div.style.padding).toBe('2rem')
+    })
+
+    it('placeholder div text has color #6a6a8a', () => {
+      const { container } = render(<BrowserPanel sessionId={null} />)
+      const div = container.firstElementChild as HTMLElement
+      // jsdom normalizes hex colors to rgb() — #6a6a8a = rgb(106, 106, 138)
+      expect(div.style.color).toBe('rgb(106, 106, 138)')
+    })
+
+    it('placeholder div text is centered', () => {
+      const { container } = render(<BrowserPanel sessionId={null} />)
+      const div = container.firstElementChild as HTMLElement
+      expect(div.style.textAlign).toBe('center')
+    })
+  })
+
+  describe('iframe (with sessionId)', () => {
+    it('renders an iframe when sessionId is provided', () => {
+      const { container } = render(<BrowserPanel sessionId="session-abc" />)
+      expect(container.querySelector('iframe')).toBeTruthy()
+    })
+
+    it('does not render placeholder text when sessionId is provided', () => {
+      render(<BrowserPanel sessionId="session-abc" />)
+      expect(screen.queryByText('Select a session to view the browser')).toBeNull()
+    })
+
+    it('iframe has title "Browser - noVNC"', () => {
+      const { container } = render(<BrowserPanel sessionId="session-abc" />)
+      const iframe = container.querySelector('iframe') as HTMLIFrameElement
+      expect(iframe.title).toBe('Browser - noVNC')
+    })
+
+    it('iframe has width 100%', () => {
+      const { container } = render(<BrowserPanel sessionId="session-abc" />)
+      const iframe = container.querySelector('iframe') as HTMLIFrameElement
+      expect(iframe.style.width).toBe('100%')
+    })
+
+    it('iframe has height 100%', () => {
+      const { container } = render(<BrowserPanel sessionId="session-abc" />)
+      const iframe = container.querySelector('iframe') as HTMLIFrameElement
+      expect(iframe.style.height).toBe('100%')
+    })
+
+    it('iframe has no border', () => {
+      const { container } = render(<BrowserPanel sessionId="session-abc" />)
+      const iframe = container.querySelector('iframe') as HTMLIFrameElement
+      // jsdom expands border shorthand — check borderStyle which carries the 'none' value
+      expect(iframe.style.borderStyle).toBe('none')
+    })
+
+    it('iframe has dark background color #0a0a1a', () => {
+      const { container } = render(<BrowserPanel sessionId="session-abc" />)
+      const iframe = container.querySelector('iframe') as HTMLIFrameElement
+      // jsdom normalizes hex colors to rgb() — #0a0a1a = rgb(10, 10, 26)
+      expect(iframe.style.background).toBe('rgb(10, 10, 26)')
+    })
+
+    it('iframe has clipboard allow attribute', () => {
+      const { container } = render(<BrowserPanel sessionId="session-abc" />)
+      const iframe = container.querySelector('iframe') as HTMLIFrameElement
+      expect(iframe.getAttribute('allow')).toBe('clipboard-read; clipboard-write')
+    })
+  })
+
+  describe('getVncUrl() — URL detection', () => {
+    it('returns cloudflared HTTPS URL when hostname is research.ampbox.io', () => {
+      Object.defineProperty(window, 'location', {
+        configurable: true,
+        writable: true,
+        value: { hostname: 'research.ampbox.io' },
+      })
+      const { container } = render(<BrowserPanel sessionId="session-1" />)
+      const iframe = container.querySelector('iframe') as HTMLIFrameElement
+      expect(iframe.src).toBe(
+        'https://vnc.ampbox.io/vnc.html?autoconnect=true&resize=remote&quality=6&compression=2'
+      )
+    })
+
+    it('returns localhost http URL with port 6080 when hostname is localhost', () => {
+      Object.defineProperty(window, 'location', {
+        configurable: true,
+        writable: true,
+        value: { hostname: 'localhost' },
+      })
+      const { container } = render(<BrowserPanel sessionId="session-1" />)
+      const iframe = container.querySelector('iframe') as HTMLIFrameElement
+      expect(iframe.src).toBe(
+        'http://localhost:6080/vnc.html?autoconnect=true&resize=remote&quality=6&compression=2'
+      )
+    })
+
+    it('returns http URL with other hostname when not research.ampbox.io', () => {
+      Object.defineProperty(window, 'location', {
+        configurable: true,
+        writable: true,
+        value: { hostname: '192.168.1.100' },
+      })
+      const { container } = render(<BrowserPanel sessionId="session-1" />)
+      const iframe = container.querySelector('iframe') as HTMLIFrameElement
+      expect(iframe.src).toBe(
+        'http://192.168.1.100:6080/vnc.html?autoconnect=true&resize=remote&quality=6&compression=2'
+      )
+    })
+
+    it('URL includes autoconnect=true query param', () => {
+      const { container } = render(<BrowserPanel sessionId="session-1" />)
+      const iframe = container.querySelector('iframe') as HTMLIFrameElement
+      expect(iframe.src).toContain('autoconnect=true')
+    })
+
+    it('URL includes resize=remote query param', () => {
+      const { container } = render(<BrowserPanel sessionId="session-1" />)
+      const iframe = container.querySelector('iframe') as HTMLIFrameElement
+      expect(iframe.src).toContain('resize=remote')
+    })
+
+    it('URL includes quality=6 query param', () => {
+      const { container } = render(<BrowserPanel sessionId="session-1" />)
+      const iframe = container.querySelector('iframe') as HTMLIFrameElement
+      expect(iframe.src).toContain('quality=6')
+    })
+
+    it('URL includes compression=2 query param', () => {
+      const { container } = render(<BrowserPanel sessionId="session-1" />)
+      const iframe = container.querySelector('iframe') as HTMLIFrameElement
+      expect(iframe.src).toContain('compression=2')
+    })
+  })
+})