diff --git a/moli-renderer-v8/src/network/request_client.rs b/moli-renderer-v8/src/network/request_client.rs
index 70e3824b5c..365954720a 100644
--- a/moli-renderer-v8/src/network/request_client.rs
+++ b/moli-renderer-v8/src/network/request_client.rs
@@ -282,7 +282,7 @@ impl ResourceRequestClient {
         request: Request,
     ) -> Result<Response> {
         let request = self.apply_network_policy(request)?;
-        if let Some(result) = local_text_response(&request.url) {
+        if let Some(result) = local_text_response(&request) {
             return result;
         }
         let timing_enabled = moli_trace::cdp_nav_timing_enabled();
@@ -446,7 +446,7 @@ impl ResourceRequestClient {
         F: FnOnce(Result<Response>) + Send + 'static,
     {
         let request = self.apply_network_policy(request)?;
-        if let Some(result) = local_text_response(&request.url) {
+        if let Some(result) = local_text_response(&request) {
             let task_runner = resource_load.task_runner();
             task_runner.spawn(async move {
                 resource_load.finish();
@@ -662,7 +662,7 @@ impl ResourceRequestClient {
     where
         F: FnOnce(Result<Response>) + Send + 'static,
     {
-        if let Some(result) = local_text_response(&request.url) {
+        if let Some(result) = local_text_response(&request) {
             callback(result);
             return Ok(());
         }
@@ -676,7 +676,7 @@ impl ResourceRequestClient {
         request: Request,
         cancel_handle: FetchCancelHandle,
     ) -> Result<StreamingRawResponse> {
-        if let Some(response) = local_text_response(&request.url) {
+        if let Some(response) = local_text_response(&request) {
             return streaming_raw_response_from_local_response(response?);
         }
 
@@ -712,7 +712,7 @@ impl ResourceRequestClient {
         request: Request,
         cancel_handle: FetchCancelHandle,
     ) -> Result<NetworkFetchResult<StreamingRawResponse>> {
-        if let Some(response) = local_text_response(&request.url) {
+        if let Some(response) = local_text_response(&request) {
             return Ok(NetworkFetchResult::without_request_observation(
                 streaming_raw_response_from_local_response(response?)?,
             ));
@@ -1121,8 +1121,8 @@ fn streaming_raw_response_from_cached_subresource(
     streaming_raw_response_from_head_and_body(head, response.clone_body_bytes())
 }
 
-fn local_text_response(url: &url::Url) -> Option<Result<Response>> {
-    crate::network_host::local_url_response_result(url)
+fn local_text_response(request: &Request) -> Option<Result<Response>> {
+    crate::network_host::local_url_response_result(&request.url, &request.method)
         .map(|result| result.map_err(anyhow::Error::msg))
 }
 
diff --git a/moli-renderer-v8/src/network/request_client/tests.rs b/moli-renderer-v8/src/network/request_client/tests.rs
index 2f076e64ed..1791cf44ba 100644
--- a/moli-renderer-v8/src/network/request_client/tests.rs
+++ b/moli-renderer-v8/src/network/request_client/tests.rs
@@ -994,6 +994,66 @@ async fn text_stream_fetch_handles_local_data_stylesheet_urls() -> Result<()> {
     Ok(())
 }
 
+#[tokio::test(flavor = "multi_thread")]
+async fn local_blob_method_errors_reach_streaming_and_callback_consumers() -> Result<()> {
+    let loader = ResourceRequestClient::new(&FetchConfig::default())?;
+    let origin = moli_url::WebOrigin::from_url(&Url::parse("https://method.test/page")?);
+    for method in [
+        "HEAD", "POST", "PUT", "DELETE", "OPTIONS", "PATCH", "CUSTOM",
+    ] {
+        let request = Request::new_browser_bytes(
+            method,
+            "blob:https://method.test/unregistered",
+            None,
+            Vec::new(),
+            origin.clone(),
+        )?;
+        let expected = format!("blob URL fetch requires GET, got `{method}`");
+        let error = loader.fetch_text_stream(request.clone()).await.unwrap_err();
+        assert_eq!(error.to_string(), expected);
+        let error = loader
+            .fetch_cacheable_script_text_stream(request.clone())
+            .await
+            .unwrap_err();
+        assert_eq!(error.to_string(), expected);
+        let error = loader
+            .fetch_raw_stream_with_cancel(request.clone(), FetchCancelHandle::new())
+            .await
+            .expect_err("raw stream must reject non-GET blob requests");
+        assert_eq!(error.to_string(), expected);
+        let error = loader
+            .fetch_raw_stream_with_cancel_and_network_metadata(
+                request.clone(),
+                FetchCancelHandle::new(),
+            )
+            .await
+            .expect_err("observed raw stream must reject non-GET blob requests");
+        assert_eq!(error.to_string(), expected);
+        let (tx, rx) = oneshot::channel();
+        loader.fetch_text_callback(request, move |result| {
+            tx.send(result).expect("callback receiver is live");
+        })?;
+        let error = rx.await?.unwrap_err();
+        assert_eq!(error.to_string(), expected);
+
+        let data = loader
+            .fetch_text_stream(Request::new_browser_bytes(
+                method,
+                "data:text/plain,payload",
+                None,
+                Vec::new(),
+                origin.clone(),
+            )?)
+            .await?;
+        assert_eq!(
+            data.status, 200,
+            "data: must not inherit the blob method restriction"
+        );
+        assert_eq!(data.body_text(), "payload");
+    }
+    Ok(())
+}
+
 #[tokio::test(flavor = "multi_thread")]
 async fn concurrent_script_text_waiter_preserves_owner_cache_state() -> Result<()> {
     let listener = TcpListener::bind("127.0.0.1:0").await?;
diff --git a/moli-renderer-v8/src/network_host/browser_response.rs b/moli-renderer-v8/src/network_host/browser_response.rs
index 2b4dbc345b..151521872b 100644
--- a/moli-renderer-v8/src/network_host/browser_response.rs
+++ b/moli-renderer-v8/src/network_host/browser_response.rs
@@ -48,8 +48,9 @@ pub(crate) fn data_url_response(url: &url::Url) -> Option<Response> {
     ))
 }
 
+/// Reads a local resource for consumers whose requests always use GET.
 pub(crate) fn local_url_response(url: &url::Url) -> Option<Response> {
-    local_url_response_result(url).and_then(Result::ok)
+    local_url_response_result(url, "GET").and_then(Result::ok)
 }
 
 /// Resolves renderer-owned URL schemes without falling through to the network
@@ -58,8 +59,15 @@ pub(crate) fn local_url_response(url: &url::Url) -> Option<Response> {
 /// `None` means that the URL is not owned by this resolver. `Some(Err(..))`
 /// means that it is a local URL and therefore must fail locally instead of
 /// being handed to libcurl.
-pub(crate) fn local_url_response_result(url: &url::Url) -> Option<Result<Response, String>> {
+/// `method` is the request's already normalized method.
+pub(crate) fn local_url_response_result(
+    url: &url::Url,
+    method: &str,
+) -> Option<Result<Response, String>> {
     match url.scheme() {
+        "blob" if method != "GET" => {
+            Some(Err(format!("blob URL fetch requires GET, got `{method}`")))
+        }
         "blob" => {
             Some(blob_url_response(url).ok_or_else(|| format!("blob URL `{url}` is unavailable")))
         }
@@ -107,7 +115,7 @@ mod tests {
     fn unavailable_blob_url_is_a_local_failure() {
         let url = url::Url::parse("blob:https://example.test/not-registered").unwrap();
 
-        let error = local_url_response_result(&url)
+        let error = local_url_response_result(&url, "GET")
             .expect("blob URL must be owned by the local resolver")
             .expect_err("an unregistered blob URL must fail locally");
 
diff --git a/moli-renderer-v8/src/network_host/fetch/bindings/paths.rs b/moli-renderer-v8/src/network_host/fetch/bindings/paths.rs
index ae5350900d..6d0184a943 100644
--- a/moli-renderer-v8/src/network_host/fetch/bindings/paths.rs
+++ b/moli-renderer-v8/src/network_host/fetch/bindings/paths.rs
@@ -144,11 +144,15 @@ pub(super) fn resolve_local_fetch(
     host: &mut JsContextHost,
     prepared: &PreparedWindowFetchRequest,
 ) -> Result<Option<Response>, String> {
-    let Some(response) = local_url_response(&prepared.resolved_url) else {
-        if prepared.resolved_url.scheme() != "blob" {
-            return Ok(None);
-        }
-        let message = FILE_NOT_FOUND_ERROR_TEXT.to_owned();
+    let Some(result) = local_url_response_result(&prepared.resolved_url, &prepared.method) else {
+        return Ok(None);
+    };
+    let response = result.map_err(|message| {
+        let message = if prepared.resolved_url.scheme() == "blob" && prepared.method == "GET" {
+            FILE_NOT_FOUND_ERROR_TEXT.to_owned()
+        } else {
+            message
+        };
         host.record_subresource_network(SubresourceNetworkRecord::failure(
             prepared.frame_id.clone(),
             prepared.document_url.clone(),
@@ -159,8 +163,8 @@ pub(super) fn resolve_local_fetch(
             SubresourceResourceType::Fetch,
             message.clone(),
         ));
-        return Err(message);
-    };
+        message
+    })?;
     host.record_subresource_network(
         SubresourceNetworkRecord::success_with_body(
             prepared.frame_id.clone(),
diff --git a/moli-renderer-v8/src/network_host/xhr/send.rs b/moli-renderer-v8/src/network_host/xhr/send.rs
index 8a09c2f800..02e0dfb46b 100644
--- a/moli-renderer-v8/src/network_host/xhr/send.rs
+++ b/moli-renderer-v8/src/network_host/xhr/send.rs
@@ -181,13 +181,22 @@ pub(super) fn xhr_send_callback<'s>(
         return;
     }
 
-    if let Some(response) = local_url_response(&prepared.resolved_url) {
-        if !xhr_is_async(scope, xhr) {
-            record_xhr_response_success(host, &prepared, &response);
-            apply_xhr_response(scope, xhr, response);
-            return;
+    if let Some(result) = local_url_response_result(&prepared.resolved_url, &prepared.method) {
+        match result {
+            Ok(response) if async_request => {
+                queue_local_xhr_response(scope, host, xhr, prepared, response);
+            }
+            Ok(response) => {
+                record_xhr_response_success(host, &prepared, &response);
+                apply_xhr_response(scope, xhr, response);
+            }
+            Err(message) if async_request => {
+                record_url_policy_xhr_failure(scope, host, xhr, prepared, message);
+            }
+            Err(message) => {
+                record_synchronous_xhr_failure(scope, host, xhr, prepared, message);
+            }
         }
-        queue_local_xhr_response(scope, host, xhr, prepared, response);
         return;
     }
 
diff --git a/moli-renderer-v8/src/runtime/page_vm/followed_navigation.rs b/moli-renderer-v8/src/runtime/page_vm/followed_navigation.rs
index 03f70fca45..74ad7a85a0 100644
--- a/moli-renderer-v8/src/runtime/page_vm/followed_navigation.rs
+++ b/moli-renderer-v8/src/runtime/page_vm/followed_navigation.rs
@@ -74,8 +74,10 @@ pub(super) async fn load_followed_location_navigation(
 ) -> Result<LoadedFollowedLocationNavigation> {
     debug!(%url, "starting pre-commit location navigation fetch");
     if let Some(response) = about_blank_navigation_response(&url)
-        .or_else(|| crate::network_host::local_url_response(&url))
+        .map(Ok)
+        .or_else(|| crate::network_host::local_url_response_result(&url, &request_method))
     {
+        let response = response.map_err(anyhow::Error::msg)?;
         if matches!(response.status, 204 | 205) {
             return Ok(LoadedFollowedLocationNavigation::NoDocument);
         }
@@ -1256,7 +1258,11 @@ impl PageVm {
 
 #[cfg(test)]
 mod tests {
-    use super::{about_blank_navigation_response, build_followed_location_navigation_request};
+    use super::{
+        LoadedFollowedLocationNavigation, about_blank_navigation_response,
+        build_followed_location_navigation_request, load_followed_location_navigation,
+    };
+    use crate::network::ResourceRequestClient;
     use moli_fetch::{BrowserNavigationRequestKind, outgoing_request_headers};
     use url::Url;
 
@@ -1363,6 +1369,49 @@ mod tests {
         );
     }
 
+    #[tokio::test]
+    async fn local_navigation_fetch_preserves_the_request_method() {
+        let loader = ResourceRequestClient::new(&Default::default()).unwrap();
+        let initiator = Url::parse("https://navigation.test/form").unwrap();
+        for method in ["HEAD", "POST"] {
+            let result = load_followed_location_navigation(
+                &loader,
+                initiator.clone(),
+                Url::parse("blob:https://navigation.test/unregistered").unwrap(),
+                method.to_owned(),
+                None,
+                Vec::new(),
+                BrowserNavigationRequestKind::Navigate,
+            )
+            .await;
+            match result {
+                Err(error) => assert_eq!(
+                    error.to_string(),
+                    format!("blob URL fetch requires GET, got `{method}`")
+                ),
+                Ok(_) => panic!("blob navigation must not substitute GET for {method}"),
+            }
+        }
+        let data = load_followed_location_navigation(
+            &loader,
+            initiator,
+            Url::parse("data:text/html,<p>payload</p>").unwrap(),
+            "POST".to_owned(),
+            Some(b"upload".to_vec()),
+            Vec::new(),
+            BrowserNavigationRequestKind::Navigate,
+        )
+        .await
+        .unwrap();
+        assert!(matches!(
+            data,
+            LoadedFollowedLocationNavigation::ExternalDocument {
+                response_status: 200,
+                ..
+            }
+        ));
+    }
+
     #[test]
     fn about_blank_followed_location_navigation_uses_synthetic_response() {
         let url = Url::parse("about:blank#fragment").unwrap();
diff --git a/moli-renderer-v8/src/runtime/page_vm/tests/fetch_xhr.rs b/moli-renderer-v8/src/runtime/page_vm/tests/fetch_xhr.rs
index 28ae6f987b..da79d11739 100644
--- a/moli-renderer-v8/src/runtime/page_vm/tests/fetch_xhr.rs
+++ b/moli-renderer-v8/src/runtime/page_vm/tests/fetch_xhr.rs
@@ -4000,6 +4000,129 @@ async fn window_fetch_file_url_rejects_before_interception_or_transport() {
     .await;
 }
 
+#[tokio::test]
+async fn blob_fetch_and_xhr_reject_non_get_methods_in_window_and_worker() {
+    run_page_vm_async_test(async move {
+        for worker in [false, true] {
+            let mut page_vm = test_page_vm();
+            let local_executor = page_vm.local_executor.clone();
+            let probe = r#"(async () => {
+                const check = (value, message) => { if (!value) throw new Error(message); };
+                const blob = URL.createObjectURL(new Blob(['payload'], {type: 'text/plain'}));
+                try {
+                    for (const api of ['fetch', 'fetch-clone', 'xhr-async', 'xhr-sync']) {
+                        for (const scheme of ['blob', 'data']) {
+                            const raw = scheme === 'blob' ? blob : 'data:text/plain,payload';
+                            const methods = scheme === 'blob'
+                                ? ['GET', 'gEt', 'HEAD', 'POST', 'PUT', 'DELETE', 'OPTIONS', 'PATCH', 'CUSTOM']
+                                : ['GET', 'POST', 'CUSTOM'];
+                            for (const fragment of ['', '#fragment']) {
+                                for (const method of methods) {
+                                    const url = raw + fragment;
+                                    const success = scheme === 'data' || method.toUpperCase() === 'GET';
+                                    const label = [api, scheme, fragment, method].join(':');
+                                    if (api.startsWith('fetch')) {
+                                        let response;
+                                        try {
+                                            response = await (api === 'fetch-clone'
+                                                ? fetch(new Request(url, {method}).clone())
+                                                : fetch(url, {method}));
+                                        } catch (error) {
+                                            check(!success && error instanceof TypeError, label + ': wrong rejection ' + error);
+                                            continue;
+                                        }
+                                        check(success, label + ': unexpectedly fulfilled');
+                                        check(response.status === 200 && response.url.split('#')[0] === raw, label + ': response metadata');
+                                        check(await response.text() === 'payload', label + ': response body');
+                                        continue;
+                                    }
+                                    const async = api === 'xhr-async';
+                                    const xhr = new XMLHttpRequest();
+                                    xhr.open(method, url, async);
+                                    const checkResponse = () => {
+                                        check(xhr.readyState === 4 && xhr.status === (success ? 200 : 0), label + ': state/status');
+                                        check(xhr.responseText === (success ? 'payload' : ''), label + ': response text');
+                                        check(xhr.responseURL.split('#')[0] === (success ? raw : ''), label + ': response URL');
+                                        check(xhr.getResponseHeader('Content-Type') === (success ? 'text/plain' : null), label + ': headers');
+                                    };
+                                    if (!async) {
+                                        let failure;
+                                        try { xhr.send(); } catch (error) { failure = error; }
+                                        check(success ? failure === undefined : failure instanceof DOMException && failure.name === 'NetworkError', label + ': sync exception');
+                                        checkResponse();
+                                        continue;
+                                    }
+                                    await new Promise((resolve, reject) => {
+                                        let returned = false;
+                                        const events = [];
+                                        xhr.onload = () => events.push('load');
+                                        xhr.onerror = () => events.push('error');
+                                        xhr.onloadend = () => {
+                                            events.push('loadend');
+                                            try {
+                                                check(returned, label + ': completion during send');
+                                                check(events.join(',') === (success ? 'load,loadend' : 'error,loadend'), label + ': terminal events');
+                                                checkResponse();
+                                                resolve();
+                                            } catch (error) { reject(error); }
+                                        };
+                                        xhr.send();
+                                        returned = true;
+                                    });
+                                }
+                            }
+                        }
+                    }
+                } finally { URL.revokeObjectURL(blob); }
+            })()"#;
+            let script = if worker {
+                let source = serde_json::to_string(&format!(
+                    "{probe}.then(() => postMessage('ok'), error => postMessage(String(error)))"
+                ))
+                .expect("worker source");
+                format!(
+                    r#"globalThis.__blobMethodResult = 'pending';
+                    const source = URL.createObjectURL(new Blob([{source}]));
+                    const worker = new Worker(source);
+                    worker.onmessage = event => {{
+                        globalThis.__blobMethodResult = event.data;
+                        worker.terminate();
+                        URL.revokeObjectURL(source);
+                    }};
+                    worker.onerror = event => {{ globalThis.__blobMethodResult = event.message; }};"#
+                )
+            } else {
+                format!(
+                    "globalThis.__blobMethodResult = 'pending'; {probe}.then(() => {{ globalThis.__blobMethodResult = 'ok'; }}, error => {{ globalThis.__blobMethodResult = String(error); }})"
+                )
+            };
+            let (result, network_output) = local_executor
+                .run(async move {
+                    page_vm.vm_mut().eval(&script)?;
+                    drive_websocket_until_done(
+                        &mut page_vm,
+                        "String(globalThis.__blobMethodResult !== 'pending')",
+                        "blob method checks should complete",
+                    )
+                    .await?;
+                    let result = page_vm.vm_mut().eval("globalThis.__blobMethodResult")?;
+                    Ok::<_, anyhow::Error>((result, page_vm.vm_mut().take_network_output()))
+                })
+                .await
+                .expect("blob method probe should run on owner lane");
+            assert_eq!(result, "ok", "worker={worker}");
+            let (records, _, _) = split_network_output_items(network_output);
+            let failures = records
+                .iter()
+                .filter(|record| matches!(record.outcome(), SubresourceNetworkOutcome::Failure { error_text }
+                    if error_text.contains("blob URL fetch requires GET")))
+                .count();
+            assert_eq!(failures, 56, "each rejected request must record a local network error; worker={worker}");
+        }
+    })
+    .await;
+}
+
 #[tokio::test]
 async fn window_fetch_revoked_blob_url_records_file_not_found_failure() {
     run_page_vm_async_test(async move {
diff --git a/moli-renderer-v8/src/worker/global_scope/fetch.rs b/moli-renderer-v8/src/worker/global_scope/fetch.rs
index 998d460e39..38d06b2d19 100644
--- a/moli-renderer-v8/src/worker/global_scope/fetch.rs
+++ b/moli-renderer-v8/src/worker/global_scope/fetch.rs
@@ -166,11 +166,11 @@ pub(in crate::worker) fn spawn_worker_fetch_network(
                 .validate_request_mode(request_mode, &moli_url::WebOrigin::from_url(&document_url))
         {
             (Err(message), None)
-        } else if matches!(resolved_url.scheme(), "blob" | "data") {
+        } else if let Some(result) = local_url_response_result(&resolved_url, &method) {
             (
-                local_url_response(&resolved_url)
+                result
                     .map(|response| WorkerFetchResponse::Materialized(Box::new(response)))
-                    .ok_or_else(|| format!("fetch: local url `{resolved_url}` is unavailable")),
+                    .map_err(|error| format!("fetch: {error}")),
                 None,
             )
         } else {
diff --git a/moli-renderer-v8/src/worker/global_scope/mod.rs b/moli-renderer-v8/src/worker/global_scope/mod.rs
index 350d6dbdf6..89c8399e3f 100644
--- a/moli-renderer-v8/src/worker/global_scope/mod.rs
+++ b/moli-renderer-v8/src/worker/global_scope/mod.rs
@@ -83,7 +83,7 @@ use crate::network_host::{
     fetch_browser_subresource_raw_stream_with_preflight_headers_and_network_metadata,
     fetch_browser_subresource_with_preflight_headers_and_network_metadata,
     filter_cors_exposed_response_headers, filter_headers_for_guard, has_header,
-    is_cors_policy_failure_message, local_url_response, parse_fetch_init,
+    is_cors_policy_failure_message, local_url_response_result, parse_fetch_init,
     prepare_xhr_send_body_from_args, request_input_snapshot, request_object_credentials_mode,
     reset_xhr_response_for_request_error, resolve_context_url, set_xhr_state_bool,
     set_xhr_state_number, throw_synchronous_xhr_failure, validate_fetch_response_security_policy,
diff --git a/moli-renderer-v8/src/worker/global_scope/xhr.rs b/moli-renderer-v8/src/worker/global_scope/xhr.rs
index 78eb732466..09bfad621e 100644
--- a/moli-renderer-v8/src/worker/global_scope/xhr.rs
+++ b/moli-renderer-v8/src/worker/global_scope/xhr.rs
@@ -408,15 +408,32 @@ pub(crate) fn try_worker_xhr_send_callback<'s>(
         return true;
     }
 
-    if let Some(response) = local_url_response(&prepared.resolved_url) {
-        apply_xhr_response(scope, xhr, response);
+    let local_response = local_url_response_result(&prepared.resolved_url, &prepared.method);
+    if !async_request && let Some(result) = local_response {
+        match result {
+            Ok(response) => apply_xhr_response(scope, xhr, response),
+            Err(message) => {
+                record_worker_subresource_failure(
+                    &state.borrow(),
+                    prepared.document_url,
+                    prepared.resolved_url,
+                    prepared.method,
+                    prepared.request_headers,
+                    request_body_text(&prepared.send_body),
+                    SubresourceResourceType::Xhr,
+                    message,
+                );
+                throw_synchronous_xhr_failure(scope, xhr, &request_url, "NetworkError");
+            }
+        }
         return true;
     }
 
     let loader = state.borrow().loader.clone();
 
     let cancel_handle = FetchCancelHandle::new();
-    let intercept_request_stage = fetch_subresource_interception_enabled
+    let intercept_request_stage = local_response.is_none()
+        && fetch_subresource_interception_enabled
         && fetch_subresource_interception_resource_type.is_none_or(|expected| {
             expected.has_same_cdp_fetch_interception_type(SubresourceResourceType::Xhr)
         });
@@ -475,6 +492,17 @@ pub(crate) fn try_worker_xhr_send_callback<'s>(
     set_xhr_state_number(scope, xhr, XHR_ACTIVE_INTERNAL_ID_SLOT, xhr_id as f64);
     schedule_worker_xhr_timeout(scope, &state, xhr, xhr_id);
 
+    if let Some(result) = local_response {
+        // Local responses and network errors still complete asynchronously, so
+        // abort(), open() and timeout processing use the ordinary pending XHR.
+        let _ = state.borrow().xhr_completion_tx.send(WorkerXhrCompletion {
+            xhr_id,
+            network_request_headers: None,
+            result: result.map(|response| WorkerXhrResponse::Materialized(Box::new(response))),
+        });
+        return true;
+    }
+
     if intercept_request_stage {
         let info = PendingSubresourceFetchInfo {
             internal_id: 0,