diff --git a/moli-benchmark/wpt-cross-current/passed-cases.txt b/moli-benchmark/wpt-cross-current/passed-cases.txt
index 87bf149c05..267b73ad68 100644
--- a/moli-benchmark/wpt-cross-current/passed-cases.txt
+++ b/moli-benchmark/wpt-cross-current/passed-cases.txt
@@ -5614,6 +5614,7 @@ html/browsers/browsing-the-web/navigating-across-documents/initial-empty-documen
 html/browsers/browsing-the-web/navigating-across-documents/initial-empty-document/window-open-history-length.html
 html/browsers/browsing-the-web/navigating-across-documents/initial-empty-document/window-open-nourl.html
 html/browsers/browsing-the-web/navigating-across-documents/javascript-url-global-scope.html
+html/browsers/browsing-the-web/navigating-across-documents/javascript-url-no-beforeunload.window.js?moli-wpt-script=window
 html/browsers/browsing-the-web/navigating-across-documents/javascript-url-query-fragment-components.html
 html/browsers/browsing-the-web/navigating-across-documents/javascript-url-return-value-handling-dynamic.html
 html/browsers/browsing-the-web/navigating-across-documents/javascript-url-return-value-handling.html
diff --git a/moli-core/tests/javascript_url_lifecycle.rs b/moli-core/tests/javascript_url_lifecycle.rs
new file mode 100644
index 0000000000..17824219a6
--- /dev/null
+++ b/moli-core/tests/javascript_url_lifecycle.rs
@@ -0,0 +1,164 @@
+use anyhow::Result;
+use moli_core::runtime::{Browser, BrowserConfig};
+use moli_test_support::FixtureServer;
+use serde_json::{Value, json};
+use tokio::time::Duration;
+use url::Url;
+
+async fn child_navigation_lifecycle(via: &str, kind: &str, depth: usize) -> Result<Value> {
+    let server = FixtureServer::spawn().await?;
+    let browser = Browser::new(BrowserConfig::default())?;
+    let markup = format!(
+        r#"<!doctype html><body><script>
+          window.events = [];
+          window.staleTimerRan = false;
+          window.unloadNavigationRan = false;
+          window.finished = (async () => {{
+            async function makeFrame(owner, label) {{
+              const frame = owner.document.createElement('iframe');
+              const loaded = new Promise(resolve => frame.onload = resolve);
+              frame.src = '/compat/child-dynamic-markup-document?markup=' +
+                encodeURIComponent('<!doctype html><body>original');
+              owner.document.body.append(frame);
+              await loaded;
+              const win = frame.contentWindow;
+              for (const type of ['beforeunload', 'pagehide', 'unload'])
+                win.addEventListener(type, () => events.push(label + ':' + type));
+              win.document.addEventListener('visibilitychange', () =>
+                events.push(label + ':visibilitychange'));
+              win.addEventListener('unload', () => {{
+                win.setTimeout(() => staleTimerRan = true, 0);
+                win.location.href = 'javascript:top.unloadNavigationRan = true; void 0';
+              }});
+              return frame;
+            }}
+            const frame = await makeFrame(window, 'target');
+            let owner = frame.contentWindow;
+            for (let i = 0; i < {depth}; ++i)
+              owner = (await makeFrame(owner, 'descendant-' + i)).contentWindow;
+            const unrelated = await makeFrame(window, 'unrelated');
+            const oldDocument = frame.contentDocument;
+            const unrelatedDocument = unrelated.contentDocument;
+            let resolveDone;
+            const done = new Promise(resolve => resolveDone = resolve);
+            let loads = 0;
+            frame.onload = () => {{ loads++; resolveDone(); }};
+            window.nonStringDone = () => setTimeout(resolveDone, 0);
+            const kind = {kind:?};
+            const url = kind === 'string' ? 'javascript:"<body>replacement"' :
+              kind === 'undefined' ? 'javascript:top.nonStringDone(); void 0' :
+              '/compat/child-dynamic-markup-document?markup=' +
+                encodeURIComponent('<!doctype html><body>network');
+            const via = {via:?};
+            if (via === 'location') frame.contentWindow.location.href = url;
+            else if (via === 'src') frame.src = url;
+            else {{
+              const anchor = frame.contentDocument.createElement('a');
+              anchor.href = url;
+              frame.contentDocument.body.append(anchor);
+              anchor.click();
+            }}
+            await done;
+            await new Promise(resolve => setTimeout(resolve, 0));
+            return {{events, staleTimerRan, unloadNavigationRan, loads,
+              sameDocument: frame.contentDocument === oldDocument,
+              unrelatedUnchanged: unrelated.contentDocument === unrelatedDocument,
+              text: frame.contentDocument.body.textContent,
+              children: frame.contentWindow.length}};
+          }})();
+        </script>"#
+    );
+    let mut url = Url::parse(&server.url("/compat/child-dynamic-markup-document"))?;
+    url.query_pairs_mut().append_pair("markup", &markup);
+    let result = tokio::time::timeout(Duration::from_secs(10), async {
+        let mut page = browser.fetch(url.as_str()).await?;
+        page.evaluate_runtime_expression_with_await_async(
+            "finished.then(value => JSON.stringify(value))",
+            true,
+        )
+        .await
+    })
+    .await??;
+    let result: Value = serde_json::from_str(result["value"].as_str().unwrap())?;
+    server.shutdown().await;
+    assert_eq!(result["unrelatedUnchanged"], true, "{via}/{kind}: {result}");
+    assert_eq!(result["staleTimerRan"], false, "{via}/{kind}: {result}");
+    assert_eq!(
+        result["unloadNavigationRan"], false,
+        "{via}/{kind}: {result}"
+    );
+    Ok(result)
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn child_javascript_url_string_unloads_without_beforeunload() -> Result<()> {
+    for via in ["location", "src", "anchor"] {
+        for depth in [0, 2] {
+            let result = child_navigation_lifecycle(via, "string", depth).await?;
+            assert_eq!(result["sameDocument"], false);
+            assert_eq!(result["loads"], 1);
+            assert_eq!(result["text"], "replacement");
+            assert_eq!(result["children"], 0);
+            let events = result["events"].as_array().unwrap();
+            let labels = std::iter::once("target".to_owned())
+                .chain((0..depth).map(|index| format!("descendant-{index}")));
+            for label in labels {
+                let actual: Vec<_> = events
+                    .iter()
+                    .filter(|event| event.as_str().unwrap().starts_with(&format!("{label}:")))
+                    .cloned()
+                    .collect();
+                assert_eq!(
+                    actual,
+                    vec![
+                        json!(format!("{label}:pagehide")),
+                        json!(format!("{label}:visibilitychange")),
+                        json!(format!("{label}:unload")),
+                    ],
+                    "{via}/{depth}: {result}"
+                );
+            }
+            assert_eq!(events.len(), 3 * (depth + 1), "{via}/{depth}: {result}");
+        }
+    }
+    Ok(())
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn child_javascript_url_non_string_preserves_document_and_descendants() -> Result<()> {
+    for via in ["location", "src", "anchor"] {
+        let result = child_navigation_lifecycle(via, "undefined", 2).await?;
+        assert_eq!(result["sameDocument"], true);
+        assert_eq!(result["loads"], 0);
+        assert_eq!(result["events"], json!([]));
+        assert_eq!(result["children"], 1);
+    }
+    Ok(())
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn ordinary_child_navigation_still_dispatches_beforeunload() -> Result<()> {
+    for via in ["location", "src", "anchor"] {
+        let result = child_navigation_lifecycle(via, "network", 0).await?;
+        assert_eq!(result["sameDocument"], false);
+        assert_eq!(result["loads"], 1);
+        assert_eq!(result["text"], "network");
+        let events: Vec<_> = result["events"]
+            .as_array()
+            .unwrap()
+            .iter()
+            .filter(|event| *event != "target:visibilitychange")
+            .cloned()
+            .collect();
+        assert_eq!(
+            events,
+            vec![
+                json!("target:beforeunload"),
+                json!("target:pagehide"),
+                json!("target:unload")
+            ],
+            "{via}: {result}"
+        );
+    }
+    Ok(())
+}
diff --git a/moli-renderer-v8/src/native_bridge/context_host/child_documents/lifecycle.rs b/moli-renderer-v8/src/native_bridge/context_host/child_documents/lifecycle.rs
index 135c5f4317..c808a2211e 100644
--- a/moli-renderer-v8/src/native_bridge/context_host/child_documents/lifecycle.rs
+++ b/moli-renderer-v8/src/native_bridge/context_host/child_documents/lifecycle.rs
@@ -913,14 +913,39 @@ impl JsContextHost {
         true
     }
 
-    /// Dispatches the unload sequence used when `Document::open()` removes a
-    /// descendant frame.
-    ///
-    /// This is intentionally distinct from navigation teardown: Chromium's
-    /// document-open steps do not prompt the child with `beforeunload`, and
-    /// dispatch pagehide/visibilitychange before unload while the parent
-    /// document's listeners are still installed.
-    fn dispatch_child_browsing_context_document_open_unload_lifecycle_if_needed(
+    pub(in crate::native_bridge::context_host) fn dispatch_child_javascript_url_unload_lifecycle(
+        scope: &mut v8::PinScope<'_, '_>,
+        host_ptr: *mut Self,
+        handle: DomHandle,
+    ) {
+        let Some(document) = unsafe { &*host_ptr }.child_browsing_context_document_handle(handle) else {
+            return;
+        };
+        let mut handles = vec![handle];
+        unsafe { &*host_ptr }.collect_child_browsing_context_handles_in_document_order_from_document(
+            document,
+            &mut handles,
+        );
+        // Snapshot the documents before any unload handler can remove or
+        // replace a descendant. A new document must not inherit this unload.
+        let documents: Vec<_> = handles
+            .into_iter()
+            .filter_map(|handle| {
+                unsafe { &*host_ptr }.child_browsing_context_document_handle(handle)
+                    .map(|document| (handle, document))
+            })
+            .collect();
+        for (handle, document) in documents {
+            if unsafe { &*host_ptr }.child_browsing_context_document_handle(handle) == Some(document) {
+                Self::dispatch_child_document_unload_without_beforeunload(scope, host_ptr, handle);
+            }
+        }
+    }
+
+    /// JavaScript URL replacement and removal by `Document::open()` unload
+    /// documents without checking whether unloading is canceled. They still
+    /// dispatch the actual unload lifecycle and cancel the old window's timers.
+    fn dispatch_child_document_unload_without_beforeunload(
         scope: &mut v8::PinScope<'_, '_>,
         host_ptr: *mut Self,
         handle: DomHandle,
@@ -970,7 +995,7 @@ impl JsContextHost {
             {
                 continue;
             }
-            Self::dispatch_child_browsing_context_document_open_unload_lifecycle_if_needed(
+            Self::dispatch_child_document_unload_without_beforeunload(
                 scope, host_ptr, handle,
             );
         }
diff --git a/moli-renderer-v8/src/native_bridge/context_host/child_frame_navigation/commit.rs b/moli-renderer-v8/src/native_bridge/context_host/child_frame_navigation/commit.rs
index 9176a7efee..09afaa4533 100644
--- a/moli-renderer-v8/src/native_bridge/context_host/child_frame_navigation/commit.rs
+++ b/moli-renderer-v8/src/native_bridge/context_host/child_frame_navigation/commit.rs
@@ -679,7 +679,7 @@ impl JsContextHost {
             self.child_document_credentialless_storage_nonce(document_credentialless);
 
         self.clear_pending_child_document_loads_for_handle(handle);
-        self.dispatch_child_browsing_context_unload_lifecycle_if_needed(scope, handle);
+        Self::dispatch_child_javascript_url_unload_lifecycle(scope, self, handle);
         if !self.child_document_window_commit_preflight_is_current(handle, &window_commit_preflight)
         {
             let _ = self.finish_child_frame_navigation_without_load_dispatch(
diff --git a/moli-renderer-v8/src/native_bridge/context_host/child_frames/lookup.rs b/moli-renderer-v8/src/native_bridge/context_host/child_frames/lookup.rs
index 0e84827432..4572842d01 100644
--- a/moli-renderer-v8/src/native_bridge/context_host/child_frames/lookup.rs
+++ b/moli-renderer-v8/src/native_bridge/context_host/child_frames/lookup.rs
@@ -59,7 +59,7 @@ impl JsContextHost {
         self.lightweight_popup_id_for_document_handle(owner_document)
     }
 
-    fn collect_child_browsing_context_handles_in_document_order_from_document(
+    pub(in crate::native_bridge::context_host) fn collect_child_browsing_context_handles_in_document_order_from_document(
         &self,
         document: DomHandle,
         out: &mut Vec<DomHandle>,