diff --git a/packages/rum-core/src/browser/performanceObservable.ts b/packages/rum-core/src/browser/performanceObservable.ts
index 2c9493ba19..7de14c5d5d 100644
--- a/packages/rum-core/src/browser/performanceObservable.ts
+++ b/packages/rum-core/src/browser/performanceObservable.ts
@@ -75,6 +75,20 @@ export interface RumPerformancePaintTiming {
   toJSON(): Omit<RumPerformancePaintTiming, 'toJSON'>
 }
 
+export interface RumNotRestoredReasonDetails {
+  reason: string
+}
+
+export interface RumNotRestoredReasons {
+  children: RumNotRestoredReasons[]
+  id: string | null
+  name: string | null
+  reasons: RumNotRestoredReasonDetails[] | null
+  src: string | null
+  url: string | null
+  toJSON?(): RumNotRestoredReasons
+}
+
 export interface RumPerformanceNavigationTiming extends Omit<RumPerformanceResourceTiming, 'entryType'> {
   entryType: RumPerformanceEntryType.NAVIGATION
   initiatorType: 'navigation'
@@ -84,6 +98,7 @@ export interface RumPerformanceNavigationTiming extends Omit<RumPerformanceResou
   domContentLoadedEventEnd: RelativeTime
   domInteractive: RelativeTime
   loadEventEnd: RelativeTime
+  notRestoredReasons?: RumNotRestoredReasons | null
 
   toJSON(): Omit<RumPerformanceNavigationTiming, 'toJSON'>
 }
diff --git a/packages/rum-core/src/domain/view/viewCollection.spec.ts b/packages/rum-core/src/domain/view/viewCollection.spec.ts
index e279e711c1..3dd05bb534 100644
--- a/packages/rum-core/src/domain/view/viewCollection.spec.ts
+++ b/packages/rum-core/src/domain/view/viewCollection.spec.ts
@@ -160,6 +160,7 @@ describe('viewCollection', () => {
         long_task: {
           count: 10,
         },
+        not_restored_reasons: undefined,
         performance: {
           cls: {
             score: 1,
diff --git a/packages/rum-core/src/domain/view/viewCollection.ts b/packages/rum-core/src/domain/view/viewCollection.ts
index 3d46c4aa1d..1c705a60a5 100644
--- a/packages/rum-core/src/domain/view/viewCollection.ts
+++ b/packages/rum-core/src/domain/view/viewCollection.ts
@@ -129,6 +129,7 @@ function processViewUpdate(
         count: view.eventCounts.longTaskCount,
       },
       performance: computeViewPerformanceData(view.commonViewMetrics, view.initialViewMetrics),
+      not_restored_reasons: view.initialViewMetrics.navigationTimings?.notRestoredReasons?.toJSON?.(),
       resource: {
         count: view.eventCounts.resourceCount,
       },
diff --git a/packages/rum-core/src/domain/view/viewMetrics/trackNavigationTimings.spec.ts b/packages/rum-core/src/domain/view/viewMetrics/trackNavigationTimings.spec.ts
index bc62d32423..a42ed72e72 100644
--- a/packages/rum-core/src/domain/view/viewMetrics/trackNavigationTimings.spec.ts
+++ b/packages/rum-core/src/domain/view/viewMetrics/trackNavigationTimings.spec.ts
@@ -1,6 +1,7 @@
 import { relativeNow, type Duration, type RelativeTime } from '@datadog/browser-core'
 import type { Clock } from '@datadog/browser-core/test'
 import { mockClock, registerCleanupTask } from '@datadog/browser-core/test'
+import type { RumNotRestoredReasons } from '../../../browser/performanceObservable'
 import { mockDocumentReadyState, mockRumConfiguration } from '../../../../test'
 import type { NavigationTimings, RelevantNavigationTiming } from './trackNavigationTimings'
 import { trackNavigationTimings } from './trackNavigationTimings'
@@ -21,6 +22,15 @@ const FAKE_INCOMPLETE_NAVIGATION_ENTRY: RelevantNavigationTiming = {
   responseStart: 0 as RelativeTime,
 }
 
+const FAKE_NOT_RESTORED_REASONS: RumNotRestoredReasons = {
+  children: [],
+  id: null,
+  name: null,
+  reasons: [{ reason: 'unload-listener' }],
+  src: null,
+  url: 'https://example.com/',
+}
+
 describe('trackNavigationTimings', () => {
   let navigationTimingsCallback: jasmine.Spy<(timings: NavigationTimings) => void>
   let stop: () => void
@@ -46,6 +56,7 @@ describe('trackNavigationTimings', () => {
       domContentLoaded: 345 as Duration,
       domInteractive: 234 as Duration,
       loadEvent: 567 as Duration,
+      notRestoredReasons: undefined,
     })
   })
 
@@ -91,4 +102,77 @@ describe('trackNavigationTimings', () => {
 
     expect(navigationTimingsCallback).not.toHaveBeenCalled()
   })
+
+  it('includes notRestoredReasons when present', () => {
+    ;({ stop } = trackNavigationTimings(mockRumConfiguration(), navigationTimingsCallback, () => ({
+      ...FAKE_NAVIGATION_ENTRY,
+      notRestoredReasons: FAKE_NOT_RESTORED_REASONS,
+    })))
+
+    clock.tick(0)
+
+    expect(navigationTimingsCallback).toHaveBeenCalledOnceWith({
+      firstByte: 123 as Duration,
+      domComplete: 456 as Duration,
+      domContentLoaded: 345 as Duration,
+      domInteractive: 234 as Duration,
+      loadEvent: 567 as Duration,
+      notRestoredReasons: FAKE_NOT_RESTORED_REASONS,
+    })
+  })
+
+  it('handles null notRestoredReasons', () => {
+    ;({ stop } = trackNavigationTimings(mockRumConfiguration(), navigationTimingsCallback, () => ({
+      ...FAKE_NAVIGATION_ENTRY,
+      notRestoredReasons: null,
+    })))
+
+    clock.tick(0)
+
+    expect(navigationTimingsCallback).toHaveBeenCalledOnceWith({
+      firstByte: 123 as Duration,
+      domComplete: 456 as Duration,
+      domContentLoaded: 345 as Duration,
+      domInteractive: 234 as Duration,
+      loadEvent: 567 as Duration,
+      notRestoredReasons: null,
+    })
+  })
+
+  it('handles notRestoredReasons with nested iframes', () => {
+    const complexNotRestoredReasons: RumNotRestoredReasons = {
+      children: [
+        {
+          children: [],
+          id: 'iframe-1',
+          name: 'myFrame',
+          reasons: null,
+          src: './frame.html',
+          url: 'https://example.com/frame.html',
+        },
+        {
+          children: [],
+          id: 'iframe-2',
+          name: 'anotherFrame',
+          reasons: [{ reason: 'response-cache-control-no-store' }],
+          src: './another.html',
+          url: 'https://example.com/another.html',
+        },
+      ],
+      id: null,
+      name: null,
+      reasons: [],
+      src: null,
+      url: 'https://example.com/',
+    }
+
+    ;({ stop } = trackNavigationTimings(mockRumConfiguration(), navigationTimingsCallback, () => ({
+      ...FAKE_NAVIGATION_ENTRY,
+      notRestoredReasons: complexNotRestoredReasons,
+    })))
+
+    clock.tick(0)
+
+    expect(navigationTimingsCallback.calls.mostRecent().args[0].notRestoredReasons).toEqual(complexNotRestoredReasons)
+  })
 })
diff --git a/packages/rum-core/src/domain/view/viewMetrics/trackNavigationTimings.ts b/packages/rum-core/src/domain/view/viewMetrics/trackNavigationTimings.ts
index b70585f267..8236669c35 100644
--- a/packages/rum-core/src/domain/view/viewMetrics/trackNavigationTimings.ts
+++ b/packages/rum-core/src/domain/view/viewMetrics/trackNavigationTimings.ts
@@ -1,6 +1,6 @@
 import type { Duration, TimeoutId } from '@datadog/browser-core'
 import { setTimeout, relativeNow, runOnReadyState, clearTimeout } from '@datadog/browser-core'
-import type { RumPerformanceNavigationTiming } from '../../../browser/performanceObservable'
+import type { RumPerformanceNavigationTiming, RumNotRestoredReasons } from '../../../browser/performanceObservable'
 import type { RumConfiguration } from '../../configuration'
 import { getNavigationEntry } from '../../../browser/performanceUtils'
 
@@ -10,13 +10,19 @@ export interface NavigationTimings {
   domInteractive: Duration
   loadEvent: Duration
   firstByte: Duration | undefined
+  notRestoredReasons?: RumNotRestoredReasons | null
 }
 
 // This is a subset of "RumPerformanceNavigationTiming" that only contains the relevant fields for
 // computing navigation timings. This is useful to mock the navigation entry in tests.
 export type RelevantNavigationTiming = Pick<
   RumPerformanceNavigationTiming,
-  'domComplete' | 'domContentLoadedEventEnd' | 'domInteractive' | 'loadEventEnd' | 'responseStart'
+  | 'domComplete'
+  | 'domContentLoadedEventEnd'
+  | 'domInteractive'
+  | 'loadEventEnd'
+  | 'responseStart'
+  | 'notRestoredReasons'
 >
 
 export function trackNavigationTimings(
@@ -44,6 +50,7 @@ function processNavigationEntry(entry: RelevantNavigationTiming): NavigationTimi
     // https://github.com/GoogleChrome/web-vitals/issues/137
     // https://github.com/GoogleChrome/web-vitals/issues/162
     firstByte: entry.responseStart >= 0 && entry.responseStart <= relativeNow() ? entry.responseStart : undefined,
+    notRestoredReasons: entry.notRestoredReasons,
   }
 }
 
diff --git a/packages/rum-core/src/rawRumEvent.types.ts b/packages/rum-core/src/rawRumEvent.types.ts
index 206f213b0d..041192000f 100644
--- a/packages/rum-core/src/rawRumEvent.types.ts
+++ b/packages/rum-core/src/rawRumEvent.types.ts
@@ -11,6 +11,7 @@ import type {
   Context,
 } from '@datadog/browser-core'
 import type { PageState } from './domain/contexts/pageStateHistory'
+import type { RumNotRestoredReasons } from './browser/performanceObservable'
 
 export const RumEventType = {
   ACTION: 'action',
@@ -127,6 +128,7 @@ export interface RawRumViewEvent {
     resource: Count
     frustration: Count
     performance?: ViewPerformanceData
+    not_restored_reasons?: RumNotRestoredReasons | null
   }
   display?: ViewDisplay
   privacy?: {