diff --git a/content/browser/loader/navigation_url_loader_impl.cc b/content/browser/loader/navigation_url_loader_impl.cc
index 6fb346b..af25aee 100644
--- a/content/browser/loader/navigation_url_loader_impl.cc
+++ b/content/browser/loader/navigation_url_loader_impl.cc
@@ -72,6 +72,7 @@
 #include "content/public/browser/url_loader_throttles.h"
 #include "content/public/browser/web_ui_url_loader_factory.h"
 #include "content/public/common/content_client.h"
+#include "content/public/common/content_features.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/referrer.h"
 #include "content/public/common/url_constants.h"
@@ -1263,7 +1264,13 @@
   LogQueueTimeHistogram("Navigation.QueueTime.OnReceiveRedirect",
                         resource_request_->is_outermost_main_frame);
   net::Error error = net::OK;
-  if (!bypass_redirect_checks_ &&
+
+  bool bypass_redirect_checks =
+      base::FeatureList::IsEnabled(features::kBypassRedirectChecksPerRequest)
+          ? head->bypass_redirect_checks
+          : bypass_redirect_checks_;
+
+  if (!bypass_redirect_checks &&
       !IsSafeRedirectTarget(url_, redirect_info.new_url)) {
     error = net::ERR_UNSAFE_REDIRECT;
   } else if (--redirect_limit_ == 0) {
diff --git a/content/public/common/content_features.cc b/content/public/common/content_features.cc
index 60d0d0c4..dd32364b 100644
--- a/content/public/common/content_features.cc
+++ b/content/public/common/content_features.cc
@@ -184,6 +184,12 @@
              "BrokerFileOperationsOnDiskCacheInNetworkService",
              base::FEATURE_DISABLED_BY_DEFAULT);
 
+// Allows the decision to bypass redirect checks to be made based on the
+// specific request.
+BASE_FEATURE(kBypassRedirectChecksPerRequest,
+             "BypassRedirectChecksPerRequest",
+             base::FEATURE_ENABLED_BY_DEFAULT);
+
 // Allows pages with cache-control:no-store to enter the back/forward cache.
 // Feature params can specify whether pages with cache-control:no-store can be
 // restored if cookies change / if HTTPOnly cookies change.
diff --git a/content/public/common/content_features.h b/content/public/common/content_features.h
index f53fa32..fa304b8c 100644
--- a/content/public/common/content_features.h
+++ b/content/public/common/content_features.h
@@ -63,6 +63,7 @@
     kBlockInsecurePrivateNetworkRequestsDeprecationTrial);
 CONTENT_EXPORT BASE_DECLARE_FEATURE(
     kBrokerFileOperationsOnDiskCacheInNetworkService);
+CONTENT_EXPORT BASE_DECLARE_FEATURE(kBypassRedirectChecksPerRequest);
 CONTENT_EXPORT BASE_DECLARE_FEATURE(kCacheControlNoStoreEnterBackForwardCache);
 CONTENT_EXPORT BASE_DECLARE_FEATURE(kCapturedSurfaceControlKillswitch);
 CONTENT_EXPORT BASE_DECLARE_FEATURE(
diff --git a/extensions/browser/api/web_request/web_request_proxying_url_loader_factory.cc b/extensions/browser/api/web_request/web_request_proxying_url_loader_factory.cc
index e9a9f23..0e15df2 100644
--- a/extensions/browser/api/web_request/web_request_proxying_url_loader_factory.cc
+++ b/extensions/browser/api/web_request/web_request_proxying_url_loader_factory.cc
@@ -452,7 +452,19 @@
                           TRACE_ID_LOCAL(request_id_)),
       TRACE_EVENT_FLAG_FLOW_IN | TRACE_EVENT_FLAG_FLOW_OUT);
 
-  if (redirect_url_ != redirect_info.new_url &&
+  // An extension can intercept the headers of a response and issue a redirect
+  // to a different URL. In that case `redirect_url_` was set by the proxying
+  // extension and passed to the Network Service to synthesize a redirect.
+  // `redirect_info.new_url` is part of the synthesized redirect coming from the
+  // Network Service. If the two match, we know the extension initiated the
+  // redirect, so we can trust it.
+  bool redirect_url_comes_from_extension =
+      redirect_url_ == redirect_info.new_url;
+  if (redirect_url_comes_from_extension) {
+    head->bypass_redirect_checks = true;
+  }
+
+  if (!redirect_url_comes_from_extension &&
       !IsRedirectSafe(request_.url, redirect_info.new_url,
                       info_->is_navigation_request)) {
     OnNetworkError(CreateURLLoaderCompletionStatus(net::ERR_UNSAFE_REDIRECT));
@@ -708,6 +720,7 @@
   head->headers = base::MakeRefCounted<net::HttpResponseHeaders>(
       net::HttpUtil::AssembleRawHeaders(headers));
   head->encoded_data_length = 0;
+  head->bypass_redirect_checks = true;
 
   current_response_ = std::move(head);
   ContinueToBeforeRedirect(redirect_info, net::OK);
@@ -1212,6 +1225,10 @@
         request_, new_url, override_headers_->response_code(),
         net::RedirectUtil::GetReferrerPolicyHeader(override_headers_.get()));
 
+    // Since this is an extension-generated redirect, we need to tell
+    // the client to bypass redirect checks.
+    current_response_->bypass_redirect_checks = true;
+
     // These will get re-bound if a new request is initiated by
     // |FollowRedirect()|.
     proxied_client_receiver_.reset();
diff --git a/services/network/public/mojom/url_response_head.mojom b/services/network/public/mojom/url_response_head.mojom
index c177443..c77d065 100644
--- a/services/network/public/mojom/url_response_head.mojom
+++ b/services/network/public/mojom/url_response_head.mojom
@@ -325,4 +325,7 @@
   // True if the synthetic response is used. This indicates the response headers
   // are returned with the locally storead headers. See crbug.com/352578800.
   bool from_synthetic_response = false;
+
+  // True when a proxy will handle the redirect checks.
+  bool bypass_redirect_checks = false;
 };
diff --git a/chrome/browser/extensions/api/web_request/web_request_apitest.cc b/chrome/browser/extensions/api/web_request/web_request_apitest.cc
index 48495fa..17b7b8fb 100644
--- a/chrome/browser/extensions/api/web_request/web_request_apitest.cc
+++ b/chrome/browser/extensions/api/web_request/web_request_apitest.cc
@@ -31,6 +31,7 @@
 #include "base/test/run_until.h"
 #include "base/test/scoped_feature_list.h"
 #include "base/test/test_future.h"
+#include "base/test/with_feature_override.h"
 #include "base/time/time.h"
 #include "base/time/time_override.h"
 #include "base/values.h"
@@ -7263,6 +7264,69 @@
   EXPECT_TRUE(navigation_observer.last_navigation_succeeded());
 }
 
+class ManifestV3WebRequestApiTestWithBypassRedirectChecksPerRequest
+    : public ManifestV3WebRequestApiTest,
+      public base::test::WithFeatureOverride {
+ public:
+  ManifestV3WebRequestApiTestWithBypassRedirectChecksPerRequest()
+      : WithFeatureOverride(features::kBypassRedirectChecksPerRequest) {}
+};
+
+// Tests service workers can't redirect to unsafe URLs when WebRequest
+// extensions are proxying requests. Regression test for crbug.com/379337758.
+IN_PROC_BROWSER_TEST_P(
+    ManifestV3WebRequestApiTestWithBypassRedirectChecksPerRequest,
+    ServiceWorkerCantRedirectToUnsafeUrls) {
+  ASSERT_TRUE(StartEmbeddedTestServer());
+
+  static constexpr char kManifest[] =
+      R"({
+           "name": "MV3 WebRequest",
+           "version": "0.1",
+           "manifest_version": 3,
+           "permissions": ["webRequest", "webRequestBlocking"],
+           "host_permissions": ["<all_urls>"],
+           "background": {"service_worker": "background.js"}
+         })";
+  // Listen to all requests to ensure they're proxied.
+  static constexpr char kBackgroundJs[] =
+      R"(chrome.webRequest.onBeforeRequest.addListener(
+             (details) => { return {}; },
+             {urls: ['<all_urls>'], types: ['main_frame']},
+             ['blocking']);
+         chrome.test.sendMessage('ready');)";
+
+  TestExtensionDir test_dir;
+  test_dir.WriteManifest(kManifest);
+  test_dir.WriteFile(FILE_PATH_LITERAL("background.js"), kBackgroundJs);
+  const Extension* extension = LoadPolicyExtension(test_dir);
+  ASSERT_TRUE(extension);
+
+  // Setup a service worker that redirects all requests to a "data:" URL.
+  content::WebContents* web_contents = GetActiveWebContents();
+  const GURL sw_url = embedded_test_server()->GetURL(
+      "/service_worker/service_worker_setup_data_redirect.html");
+  EXPECT_TRUE(NavigateToURL(sw_url));
+  EXPECT_EQ("ok", EvalJs(web_contents, "setup();"));
+
+  // Navigate to a URL that the service worker is monitoring.
+  content::TestNavigationObserver nav_observer(web_contents);
+  const GURL url = embedded_test_server()->GetURL("/service_worker/test");
+
+  const bool per_request_bypass = IsParamFeatureEnabled();
+  if (per_request_bypass) {
+    EXPECT_FALSE(NavigateToURL(url));
+    EXPECT_EQ(net::ERR_UNSAFE_REDIRECT, nav_observer.last_net_error_code());
+  } else {
+    EXPECT_TRUE(NavigateToURL(url));
+    EXPECT_EQ(net::OK, nav_observer.last_net_error_code());
+  }
+}
+
+// Toggle `features::BypassRedirectChecksPerRequest`.
+INSTANTIATE_FEATURE_OVERRIDE_TEST_SUITE(
+    ManifestV3WebRequestApiTestWithBypassRedirectChecksPerRequest);
+
 class OnAuthRequiredApiTest : public ExtensionApiTest {
  public:
   static constexpr char kTestDomain[] = "a.test";
diff --git a/chrome/test/data/service_worker/service_worker_data_redirect.js b/chrome/test/data/service_worker/service_worker_data_redirect.js
new file mode 100644
index 0000000..0c0d9df
--- /dev/null
+++ b/chrome/test/data/service_worker/service_worker_data_redirect.js
@@ -0,0 +1,8 @@
+// Copyright 2025 The Chromium Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+self.addEventListener('fetch', event => {
+  event.respondWith(Response.redirect(
+    'data:text/html,<script>console.log("data")</script>'));
+});
diff --git a/chrome/test/data/service_worker/service_worker_setup_data_redirect.html b/chrome/test/data/service_worker/service_worker_setup_data_redirect.html
new file mode 100644
index 0000000..61b93f6
--- /dev/null
+++ b/chrome/test/data/service_worker/service_worker_setup_data_redirect.html
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Register a service worker that redirects to data: URLs</title>
+<script>
+async function setup() {
+  let script_file = 'service_worker_data_redirect.js';
+  await navigator.serviceWorker.register(script_file);
+  await navigator.serviceWorker.ready;
+  return 'ok';
+}
+</script>

diff --git a/chrome/browser/extensions/api/web_request/web_request_apitest.cc b/chrome/browser/extensions/api/web_request/web_request_apitest.cc
index 48495fa..17b7b8fb 100644
--- a/chrome/browser/extensions/api/web_request/web_request_apitest.cc
+++ b/chrome/browser/extensions/api/web_request/web_request_apitest.cc
@@ -31,6 +31,7 @@
 #include "base/test/run_until.h"
 #include "base/test/scoped_feature_list.h"
 #include "base/test/test_future.h"
+#include "base/test/with_feature_override.h"
 #include "base/time/time.h"
 #include "base/time/time_override.h"
 #include "base/values.h"
@@ -7263,6 +7264,69 @@
   EXPECT_TRUE(navigation_observer.last_navigation_succeeded());
 }
 
+class ManifestV3WebRequestApiTestWithBypassRedirectChecksPerRequest
+    : public ManifestV3WebRequestApiTest,
+      public base::test::WithFeatureOverride {
+ public:
+  ManifestV3WebRequestApiTestWithBypassRedirectChecksPerRequest()
+      : WithFeatureOverride(features::kBypassRedirectChecksPerRequest) {}
+};
+
+// Tests service workers can't redirect to unsafe URLs when WebRequest
+// extensions are proxying requests. Regression test for crbug.com/379337758.
+IN_PROC_BROWSER_TEST_P(
+    ManifestV3WebRequestApiTestWithBypassRedirectChecksPerRequest,
+    ServiceWorkerCantRedirectToUnsafeUrls) {
+  ASSERT_TRUE(StartEmbeddedTestServer());
+
+  static constexpr char kManifest[] =
+      R"({
+           "name": "MV3 WebRequest",
+           "version": "0.1",
+           "manifest_version": 3,
+           "permissions": ["webRequest", "webRequestBlocking"],
+           "host_permissions": ["<all_urls>"],
+           "background": {"service_worker": "background.js"}
+         })";
+  // Listen to all requests to ensure they're proxied.
+  static constexpr char kBackgroundJs[] =
+      R"(chrome.webRequest.onBeforeRequest.addListener(
+             (details) => { return {}; },
+             {urls: ['<all_urls>'], types: ['main_frame']},
+             ['blocking']);
+         chrome.test.sendMessage('ready');)";
+
+  TestExtensionDir test_dir;
+  test_dir.WriteManifest(kManifest);
+  test_dir.WriteFile(FILE_PATH_LITERAL("background.js"), kBackgroundJs);
+  const Extension* extension = LoadPolicyExtension(test_dir);
+  ASSERT_TRUE(extension);
+
+  // Setup a service worker that redirects all requests to a "data:" URL.
+  content::WebContents* web_contents = GetActiveWebContents();
+  const GURL sw_url = embedded_test_server()->GetURL(
+      "/service_worker/service_worker_setup_data_redirect.html");
+  EXPECT_TRUE(NavigateToURL(sw_url));
+  EXPECT_EQ("ok", EvalJs(web_contents, "setup();"));
+
+  // Navigate to a URL that the service worker is monitoring.
+  content::TestNavigationObserver nav_observer(web_contents);
+  const GURL url = embedded_test_server()->GetURL("/service_worker/test");
+
+  const bool per_request_bypass = IsParamFeatureEnabled();
+  if (per_request_bypass) {
+    EXPECT_FALSE(NavigateToURL(url));
+    EXPECT_EQ(net::ERR_UNSAFE_REDIRECT, nav_observer.last_net_error_code());
+  } else {
+    EXPECT_TRUE(NavigateToURL(url));
+    EXPECT_EQ(net::OK, nav_observer.last_net_error_code());
+  }
+}
+
+// Toggle `features::BypassRedirectChecksPerRequest`.
+INSTANTIATE_FEATURE_OVERRIDE_TEST_SUITE(
+    ManifestV3WebRequestApiTestWithBypassRedirectChecksPerRequest);
+
 class OnAuthRequiredApiTest : public ExtensionApiTest {
  public:
   static constexpr char kTestDomain[] = "a.test";
diff --git a/chrome/test/data/service_worker/service_worker_data_redirect.js b/chrome/test/data/service_worker/service_worker_data_redirect.js
new file mode 100644
index 0000000..0c0d9df
--- /dev/null
+++ b/chrome/test/data/service_worker/service_worker_data_redirect.js
@@ -0,0 +1,8 @@
+// Copyright 2025 The Chromium Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+self.addEventListener('fetch', event => {
+  event.respondWith(Response.redirect(
+    'data:text/html,<script>console.log("data")</script>'));
+});
diff --git a/chrome/test/data/service_worker/service_worker_setup_data_redirect.html b/chrome/test/data/service_worker/service_worker_setup_data_redirect.html
new file mode 100644
index 0000000..61b93f6
--- /dev/null
+++ b/chrome/test/data/service_worker/service_worker_setup_data_redirect.html
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Register a service worker that redirects to data: URLs</title>
+<script>
+async function setup() {
+  let script_file = 'service_worker_data_redirect.js';
+  await navigator.serviceWorker.register(script_file);
+  await navigator.serviceWorker.ready;
+  return 'ok';
+}
+</script>