diff --git a/Userland/Libraries/LibWeb/HTML/Navigable.cpp b/Userland/Libraries/LibWeb/HTML/Navigable.cpp
index a9e421ef28..6c2af8e4ad 100644
--- a/Userland/Libraries/LibWeb/HTML/Navigable.cpp
+++ b/Userland/Libraries/LibWeb/HTML/Navigable.cpp
@@ -674,8 +674,7 @@ static WebIDL::ExceptionOr<Variant<Empty, NavigationParams, NonFetchSchemeNaviga
     request->set_credentials_mode(Fetch::Infrastructure::Request::CredentialsMode::Include);
     request->set_use_url_credentials(true);
     request->set_redirect_mode(Fetch::Infrastructure::Request::RedirectMode::Manual);
-    auto replaces_client_id = TRY_OR_THROW_OOM(vm, String::from_byte_string(active_document.relevant_settings_object().id));
-    request->set_replaces_client_id(replaces_client_id);
+    request->set_replaces_client_id(active_document.relevant_settings_object().id);
     request->set_mode(Fetch::Infrastructure::Request::Mode::Navigate);
     request->set_referrer(entry->document_state->request_referrer());
 
diff --git a/Userland/Libraries/LibWeb/HTML/Scripting/Environments.cpp b/Userland/Libraries/LibWeb/HTML/Scripting/Environments.cpp
index 117b9c5861..4214fb6693 100644
--- a/Userland/Libraries/LibWeb/HTML/Scripting/Environments.cpp
+++ b/Userland/Libraries/LibWeb/HTML/Scripting/Environments.cpp
@@ -308,7 +308,7 @@ bool EnvironmentSettingsObject::is_scripting_disabled() const
 }
 
 // https://html.spec.whatwg.org/multipage/webappapis.html#module-type-allowed
-bool EnvironmentSettingsObject::module_type_allowed(AK::ByteString const& module_type) const
+bool EnvironmentSettingsObject::module_type_allowed(StringView module_type) const
 {
     // 1. If moduleType is not "javascript", "css", or "json", then return false.
     if (module_type != "javascript"sv && module_type != "css"sv && module_type != "json"sv)
diff --git a/Userland/Libraries/LibWeb/HTML/Scripting/Environments.h b/Userland/Libraries/LibWeb/HTML/Scripting/Environments.h
index 28d7800cd3..ca99e14fc1 100644
--- a/Userland/Libraries/LibWeb/HTML/Scripting/Environments.h
+++ b/Userland/Libraries/LibWeb/HTML/Scripting/Environments.h
@@ -20,7 +20,7 @@ struct Environment {
     virtual ~Environment() = default;
 
     // An id https://html.spec.whatwg.org/multipage/webappapis.html#concept-environment-id
-    ByteString id;
+    String id;
 
     // https://html.spec.whatwg.org/multipage/webappapis.html#concept-environment-creation-url
     AK::URL creation_url;
@@ -69,7 +69,7 @@ struct EnvironmentSettingsObject
     virtual JS::GCPtr<DOM::Document> responsible_document() = 0;
 
     // https://html.spec.whatwg.org/multipage/webappapis.html#api-url-character-encoding
-    virtual ByteString api_url_character_encoding() = 0;
+    virtual String api_url_character_encoding() = 0;
 
     // https://html.spec.whatwg.org/multipage/webappapis.html#api-base-url
     virtual AK::URL api_base_url() = 0;
@@ -111,7 +111,7 @@ struct EnvironmentSettingsObject
     bool is_scripting_enabled() const;
     bool is_scripting_disabled() const;
 
-    bool module_type_allowed(ByteString const& module_type) const;
+    bool module_type_allowed(StringView module_type) const;
 
     void disallow_further_import_maps();
 
diff --git a/Userland/Libraries/LibWeb/HTML/Scripting/WindowEnvironmentSettingsObject.cpp b/Userland/Libraries/LibWeb/HTML/Scripting/WindowEnvironmentSettingsObject.cpp
index 4d3a767233..4f70181571 100644
--- a/Userland/Libraries/LibWeb/HTML/Scripting/WindowEnvironmentSettingsObject.cpp
+++ b/Userland/Libraries/LibWeb/HTML/Scripting/WindowEnvironmentSettingsObject.cpp
@@ -51,7 +51,7 @@ void WindowEnvironmentSettingsObject::setup(Page& page, AK::URL const& creation_
         settings_object->target_browsing_context = reserved_environment->target_browsing_context;
 
         // 2. Set reservedEnvironment's id to the empty string.
-        reserved_environment->id = ByteString::empty();
+        reserved_environment->id = String {};
     }
 
     // 5. Otherwise, ...
@@ -60,7 +60,7 @@ void WindowEnvironmentSettingsObject::setup(Page& page, AK::URL const& creation_
         //        settings object's target browsing context to null,
         //        and settings object's active service worker to null.
         static i64 next_id = 1;
-        settings_object->id = ByteString::number(next_id++);
+        settings_object->id = MUST(String::number(next_id++));
         settings_object->target_browsing_context = nullptr;
     }
 
@@ -68,8 +68,8 @@ void WindowEnvironmentSettingsObject::setup(Page& page, AK::URL const& creation_
     //    settings object's top-level creation URL to topLevelCreationURL,
     //    and settings object's top-level origin to topLevelOrigin.
     settings_object->creation_url = creation_url;
-    settings_object->top_level_creation_url = top_level_creation_url;
-    settings_object->top_level_origin = top_level_origin;
+    settings_object->top_level_creation_url = move(top_level_creation_url);
+    settings_object->top_level_origin = move(top_level_origin);
 
     // 7. Set realm's [[HostDefined]] field to settings object.
     // Non-Standard: We store the ESO next to the web intrinsics in a custom HostDefined object
@@ -90,10 +90,10 @@ JS::GCPtr<DOM::Document> WindowEnvironmentSettingsObject::responsible_document()
 }
 
 // https://html.spec.whatwg.org/multipage/window-object.html#script-settings-for-window-objects:api-url-character-encoding
-ByteString WindowEnvironmentSettingsObject::api_url_character_encoding()
+String WindowEnvironmentSettingsObject::api_url_character_encoding()
 {
     // Return the current character encoding of window's associated Document.
-    return m_window->associated_document().encoding_or_default().to_byte_string();
+    return m_window->associated_document().encoding_or_default();
 }
 
 // https://html.spec.whatwg.org/multipage/window-object.html#script-settings-for-window-objects:api-base-url
diff --git a/Userland/Libraries/LibWeb/HTML/Scripting/WindowEnvironmentSettingsObject.h b/Userland/Libraries/LibWeb/HTML/Scripting/WindowEnvironmentSettingsObject.h
index 8a66e1b165..13b7489c16 100644
--- a/Userland/Libraries/LibWeb/HTML/Scripting/WindowEnvironmentSettingsObject.h
+++ b/Userland/Libraries/LibWeb/HTML/Scripting/WindowEnvironmentSettingsObject.h
@@ -21,7 +21,7 @@ public:
     virtual ~WindowEnvironmentSettingsObject() override;
 
     virtual JS::GCPtr<DOM::Document> responsible_document() override;
-    virtual ByteString api_url_character_encoding() override;
+    virtual String api_url_character_encoding() override;
     virtual AK::URL api_base_url() override;
     virtual Origin origin() override;
     virtual PolicyContainer policy_container() override;
diff --git a/Userland/Libraries/LibWeb/HTML/Scripting/WorkerEnvironmentSettingsObject.h b/Userland/Libraries/LibWeb/HTML/Scripting/WorkerEnvironmentSettingsObject.h
index d35fd468e3..6d55cb2d34 100644
--- a/Userland/Libraries/LibWeb/HTML/Scripting/WorkerEnvironmentSettingsObject.h
+++ b/Userland/Libraries/LibWeb/HTML/Scripting/WorkerEnvironmentSettingsObject.h
@@ -29,7 +29,7 @@ public:
     virtual ~WorkerEnvironmentSettingsObject() override = default;
 
     JS::GCPtr<DOM::Document> responsible_document() override { return nullptr; }
-    ByteString api_url_character_encoding() override { return m_api_url_character_encoding; }
+    String api_url_character_encoding() override { return m_api_url_character_encoding; }
     AK::URL api_base_url() override { return m_url; }
     Origin origin() override { return m_origin; }
     PolicyContainer policy_container() override { return m_policy_container; }
@@ -38,7 +38,7 @@ public:
 private:
     virtual void visit_edges(JS::Cell::Visitor&) override;
 
-    ByteString m_api_url_character_encoding;
+    String m_api_url_character_encoding;
     AK::URL m_url;
     HTML::Origin m_origin;
     HTML::PolicyContainer m_policy_container;