diff --git a/packages/playwright-core/src/server/har/harTracer.ts b/packages/playwright-core/src/server/har/harTracer.ts
index 930746ea08d03..96bf31724e4cc 100644
--- a/packages/playwright-core/src/server/har/harTracer.ts
+++ b/packages/playwright-core/src/server/har/harTracer.ts
@@ -265,9 +265,13 @@ export class HarTracer {
     const contentType = event.headers['content-type'];
     if (contentType)
       content.mimeType = contentType;
-    this._storeResponseContent(event.body, content, 'other');
-    if (!this._options.omitSizes)
-      harEntry.response.bodySize = event.body?.length ?? 0;
+    // Redirect and auth-retry hops are destroyed before their body is read, so the
+    // sizes stay at the -1 "not available" sentinel instead of claiming zero bytes.
+    if (event.body) {
+      this._storeResponseContent(event.body, content, 'other');
+      if (!this._options.omitSizes)
+        harEntry.response.bodySize = event.body.length;
+    }
 
     if (this._started)
       this._delegate.onEntryFinished(harEntry);
@@ -541,12 +545,7 @@ export class HarTracer {
       this._delegate.onEntryStarted(harEntry);
   }
 
-  private _storeResponseContent(buffer: Buffer | undefined, content: har.Content, resourceType: string) {
-    if (!buffer) {
-      content.size = 0;
-      return;
-    }
-
+  private _storeResponseContent(buffer: Buffer, content: har.Content, resourceType: string) {
     if (!this._options.omitSizes)
       content.size = buffer.length;
 
diff --git a/tests/library/har.spec.ts b/tests/library/har.spec.ts
index 4857202ccdc5e..abf80df23aa47 100644
--- a/tests/library/har.spec.ts
+++ b/tests/library/har.spec.ts
@@ -883,6 +883,10 @@ it('should include redirects from API request', async ({ contextFactory, server
 
   expect(redirect.timings).toBeDefined();
   expect(json.timings).toBeDefined();
+
+  // The redirect body is never read, so its sizes stay unknown rather than claiming zero.
+  expect(redirect.response.bodySize).toBe(-1);
+  expect(redirect.response.content.size).toBe(-1);
 });
 
 it('should not hang on resources served from cache', async ({ contextFactory, server, browserName, isBidi }, testInfo) => {