diff --git a/src/browser/CdpCaptureStorage.test.ts b/src/browser/CdpCaptureStorage.test.ts
index 870bed8c1b..d6699150cd 100644
--- a/src/browser/CdpCaptureStorage.test.ts
+++ b/src/browser/CdpCaptureStorage.test.ts
@@ -16,14 +16,15 @@ const NO_CACHE_COMMAND = Symbol("unsupported");
 
 const captureWithCacheResult = async (
   cacheResult: unknown,
+  storageEntries: unknown = [],
 ): Promise<Awaited<ReturnType<typeof captureStorage>>["value"]> => {
   const connection = {
-    send(method: string): Promise<unknown> {
+    send(method: string, params: Record<string, unknown>): Promise<unknown> {
       switch (method) {
         case "Storage.getUsageAndQuota":
           return Promise.resolve({ usage: 1, quota: 10 });
         case "DOMStorage.getDOMStorageItems":
-          return Promise.resolve({ entries: [] });
+          return Promise.resolve({ entries: storageEntries });
         case "IndexedDB.requestDatabaseNames":
           return Promise.resolve({ databaseNames: [] });
         case "Network.getCookies":
@@ -40,6 +41,7 @@ const captureWithCacheResult = async (
               )
             : Promise.resolve(cacheResult);
         case "CacheStorage.requestEntries":
+          expect(params.cacheId).toEqual(expect.any(String));
           return Promise.resolve({ cacheDataEntries: [], returnCount: 0 });
         default:
           return Promise.reject(new Error(`Unexpected command: ${method}`));
@@ -362,3 +364,57 @@ it("keeps an opaque cookie partition unknown without dropping its value", async
   });
   expect(storageComparison(plain, known).status).toBe("changed");
 });
+
+it("retains known storage keys and cache names when content or locator metadata is malformed", async () => {
+  const storage = await captureWithCacheResult(
+    { caches: [{ cacheName: "known-cache" }] },
+    [
+      ["known-key", 42],
+      ["valid-peer", "recorded"],
+      [42, "unknown identity"],
+    ],
+  );
+  expect(storage.local_storage_keys).toEqual(["known-key", "valid-peer"]);
+  expect(storage.session_storage_keys).toEqual(["known-key", "valid-peer"]);
+  expect(storage.cache_names).toEqual(["known-cache"]);
+  expect(storage.fingerprints_complete).toBe(false);
+  const local = storage.content_fingerprints.filter(
+    ({ scope }) => scope === "local_storage",
+  );
+  expect(local).toHaveLength(2);
+  expect(local).toContainEqual(
+    expect.objectContaining({ complete: false, value_sha256: null }),
+  );
+  expect(local).toContainEqual(
+    expect.objectContaining({
+      complete: true,
+      value_sha256: expect.any(String),
+    }),
+  );
+});
+
+it("retains cookie identity when its content is malformed without inventing a value fingerprint", async () => {
+  const known = await captureCookies([cookieBase]);
+  const unavailable = await captureCookies([
+    { ...cookieBase, value: 42 },
+    { ...cookieBase, name: 42 },
+  ]);
+  const knownCookie = known.content_fingerprints.find(
+    ({ scope }) => scope === "cookie",
+  );
+  if (knownCookie === undefined) throw new Error("Missing known cookie");
+  expect(unavailable.content_fingerprints).toEqual([
+    {
+      scope: "cookie",
+      identity_sha256: knownCookie.identity_sha256,
+      value_sha256: null,
+      complete: false,
+    },
+  ]);
+  expect(unavailable.fingerprints_complete).toBe(false);
+  expect(storageComparison(known, unavailable)).toMatchObject({
+    status: "unknown",
+    total_changes: 0,
+    changes: [],
+  });
+});
diff --git a/src/browser/CdpCaptureStorage.ts b/src/browser/CdpCaptureStorage.ts
index 9c3eae8c50..24c90e33b7 100644
--- a/src/browser/CdpCaptureStorage.ts
+++ b/src/browser/CdpCaptureStorage.ts
@@ -83,7 +83,8 @@ export const captureStorage = async (
     // Like IndexedDB names, a missing, non-array or partly unusable cache
     // list is an incomplete enumeration rather than an empty one.
     Array.isArray(cacheField) &&
-    caches.length === cacheField.length;
+    caches.length === cacheField.length &&
+    caches.every(({ id }) => id !== undefined);
   const keysExclusion = !context.input.include_storage_keys
     ? undefined
     : local.exclusion === "provider_unavailable" ||
@@ -127,7 +128,7 @@ const capturedCaches = (
   values.flatMap((cache) => {
     const name = cdpStringValue(cache.cacheName);
     const id = cdpStringValue(cache.cacheId);
-    return name === undefined || id === undefined ? [] : [{ name, id }];
+    return name === undefined ? [] : [{ name, id }];
   });
 
 const storageItems = async (
@@ -154,9 +155,14 @@ const storageItems = async (
     if (!Array.isArray(entry)) return [];
     const key = cdpStringValue(entry[0]);
     const value = cdpStringValue(entry[1]);
-    return key === undefined || value === undefined ? [] : [{ key, value }];
+    return key === undefined ? [] : [{ key, value }];
   });
-  return { items, complete: items.length === entries.length };
+  return {
+    items,
+    complete:
+      items.length === entries.length &&
+      items.every(({ value }) => value !== undefined),
+  };
 };
 
 const stringArray = (value: unknown): readonly string[] =>
diff --git a/src/browser/CdpCaptureStorageFingerprints.ts b/src/browser/CdpCaptureStorageFingerprints.ts
index 3d2e33103d..b01228f395 100644
--- a/src/browser/CdpCaptureStorageFingerprints.ts
+++ b/src/browser/CdpCaptureStorageFingerprints.ts
@@ -20,14 +20,14 @@ type StorageFingerprint =
 export interface CapturedStorageItems {
   readonly items: readonly {
     readonly key: string;
-    readonly value: string;
+    readonly value: string | undefined;
   }[];
   readonly complete: boolean;
 }
 
 export interface CapturedCache {
   readonly name: string;
-  readonly id: string;
+  readonly id: string | undefined;
 }
 
 interface StorageFingerprintContext {
@@ -106,7 +106,7 @@ const addStorageItems = (
       scope,
       identity: item.key,
       value: item.value,
-      complete: true,
+      complete: item.value !== undefined,
     });
 };
 
@@ -139,12 +139,7 @@ const addCookies = async (
     const value = cdpStringValue(cookie.value);
     const domain = cdpStringValue(cookie.domain);
     const path = cdpStringValue(cookie.path);
-    if (
-      name === undefined ||
-      value === undefined ||
-      domain === undefined ||
-      path === undefined
-    ) {
+    if (name === undefined || domain === undefined || path === undefined) {
       run.state.complete = false;
       continue;
     }
@@ -163,7 +158,7 @@ const addCookies = async (
         ...(partitionOpaque ? { partition_opaque: true } : {}),
       },
       value,
-      complete: !partitionOpaque,
+      complete: value !== undefined && !partitionOpaque,
     });
   }
 };
@@ -357,6 +352,10 @@ const addCaches = async (
   caches: readonly CapturedCache[],
 ): Promise<void> => {
   for (const cache of caches) {
+    if (cache.id === undefined) {
+      run.state.complete = false;
+      continue;
+    }
     let skipCount = 0;
     let returnCount: number | undefined;
     while (returnCount === undefined || skipCount < returnCount) {