diff --git a/analysis_options.yaml b/analysis_options.yaml
index 2156d3804df6..d384eac0e616 100644
--- a/analysis_options.yaml
+++ b/analysis_options.yaml
@@ -6,7 +6,6 @@ include: all_lint_rules.yaml
 analyzer:
   # TODO(rrousselGit): disable implicit-cast/implicit-dynamic
   errors:
-    import_of_legacy_library_into_null_safe: ignore
     # Otherwise cause the import of all_lint_rules to warn because of some rules conflicts.
     # We explicitly enabled even conflicting rules and are fixing the conflict
     # in this file
@@ -43,6 +42,8 @@ linter:
     prefer_mixin: false
     public_member_api_docs: false
 
+    invalid_runtime_check_with_js_interop_types: true
+
     #############
 
     # Far too verbose, and not that big of a deal when using parameter_assignments
diff --git a/packages/_flutterfire_internals/pubspec.yaml b/packages/_flutterfire_internals/pubspec.yaml
index 2e4a2093c68c..e69f3b968cfe 100755
--- a/packages/_flutterfire_internals/pubspec.yaml
+++ b/packages/_flutterfire_internals/pubspec.yaml
@@ -5,7 +5,7 @@ repository: https://github.com/firebase/flutterfire/tree/master/packages/_flutte
 version: 1.3.35
 
 environment:
-  sdk: '>=3.2.0 <4.0.0'
+  sdk: ^3.4.0
   flutter: '>=3.3.0'
 
 dependencies:
diff --git a/packages/cloud_firestore/cloud_firestore_web/lib/src/interop/firestore.dart b/packages/cloud_firestore/cloud_firestore_web/lib/src/interop/firestore.dart
index 7f05e9e5e41c..a9bc71a3000a 100644
--- a/packages/cloud_firestore/cloud_firestore_web/lib/src/interop/firestore.dart
+++ b/packages/cloud_firestore/cloud_firestore_web/lib/src/interop/firestore.dart
@@ -257,11 +257,11 @@ class LoadBundleTaskProgress
   LoadBundleTaskProgress._fromJsObject(
     firestore_interop.LoadBundleTaskProgressJsImpl jsObject,
   )   : taskState = convertToTaskState(jsObject.taskState.toDart.toLowerCase()),
-        bytesLoaded = jsObject.bytesLoaded is JSNumber
+        bytesLoaded = jsObject.bytesLoaded.isA<JSNumber>()
             ? (jsObject.bytesLoaded as JSNumber).toDartInt
             : int.parse((jsObject.bytesLoaded as JSString).toDart),
         documentsLoaded = jsObject.documentsLoaded.toDartInt,
-        totalBytes = jsObject.totalBytes is JSNumber
+        totalBytes = jsObject.totalBytes.isA<JSNumber>()
             ? (jsObject.totalBytes as JSNumber).toDartInt
             : int.parse((jsObject.totalBytes as JSString).toDart),
         totalDocuments = jsObject.totalDocuments.toDartInt,
diff --git a/packages/cloud_firestore/cloud_firestore_web/lib/src/interop/firestore_interop.dart b/packages/cloud_firestore/cloud_firestore_web/lib/src/interop/firestore_interop.dart
index b1c4890235b4..ffbdb9b4256f 100644
--- a/packages/cloud_firestore/cloud_firestore_web/lib/src/interop/firestore_interop.dart
+++ b/packages/cloud_firestore/cloud_firestore_web/lib/src/interop/firestore_interop.dart
@@ -396,16 +396,9 @@ extension FieldPathExtension on FieldPath {
 }
 
 @JS('GeoPoint')
-@staticInterop
-external GeoPointJsImpl get GeoPointConstructor;
-
-@JS('GeoPoint')
-@staticInterop
-class GeoPointJsImpl {
+extension type GeoPointJsImpl._(JSObject _) implements JSObject {
   external factory GeoPointJsImpl(JSNumber latitude, JSNumber longitude);
-}
 
-extension GeoPointJsImplExtension on GeoPointJsImpl {
   /// The latitude of this GeoPoint instance.
   external JSNumber get latitude;
 
@@ -417,19 +410,11 @@ extension GeoPointJsImplExtension on GeoPointJsImpl {
 }
 
 @JS('Bytes')
-@staticInterop
-external BytesJsImpl get BytesConstructor;
-
-@JS('Bytes')
-@staticInterop
-@anonymous
-abstract class BytesJsImpl {
+extension type BytesJsImpl(JSObject _) implements JSObject {
   external static BytesJsImpl fromBase64JSString(JSString base64);
 
   external static BytesJsImpl fromUint8Array(JSUint8Array list);
-}
 
-extension BytesJsImplExtension on BytesJsImpl {
   external JSString toBase64();
 
   external JSUint8Array toUint8Array();
diff --git a/packages/cloud_firestore/cloud_firestore_web/lib/src/interop/utils/utils.dart b/packages/cloud_firestore/cloud_firestore_web/lib/src/interop/utils/utils.dart
index 33d3a5a132de..0b74f4ba2ef6 100644
--- a/packages/cloud_firestore/cloud_firestore_web/lib/src/interop/utils/utils.dart
+++ b/packages/cloud_firestore/cloud_firestore_web/lib/src/interop/utils/utils.dart
@@ -12,7 +12,7 @@ import '../firestore.dart';
 /// Returns Dart representation from JS Object.
 dynamic dartify(dynamic object) {
   // Convert JSObject to Dart equivalents directly
-  if (object is! JSObject) {
+  if (object.isA<JSObject>()) {
     return object;
   }
 
@@ -21,7 +21,7 @@ dynamic dartify(dynamic object) {
   if (jsObject.instanceof(DocumentReferenceJsConstructor as JSFunction)) {
     return DocumentReference.getInstance(jsObject as DocumentReferenceJsImpl);
   }
-  if (jsObject.instanceof(GeoPointConstructor as JSFunction)) {
+  if (jsObject.isA<GeoPointJsImpl>()) {
     return jsObject;
   }
   if (jsObject.instanceof(TimestampJsConstructor as JSFunction)) {
@@ -29,7 +29,7 @@ dynamic dartify(dynamic object) {
     return Timestamp(
         castedJSObject.seconds.toDartInt, castedJSObject.nanoseconds.toDartInt);
   }
-  if (jsObject.instanceof(BytesConstructor as JSFunction)) {
+  if (jsObject.isA<BytesJsImpl>()) {
     return jsObject as BytesJsImpl;
   }
 
@@ -85,11 +85,12 @@ JSAny? jsify(Object? dartObject) {
     return jsifyFieldValue(dartObject);
   }
 
+  // ignore: invalid_runtime_check_with_js_interop_types
   if (dartObject is BytesJsImpl) {
     return dartObject as JSAny;
   }
 
-  // NOTE: if the firestore JS lib is not imported, we'll get a DDC warning here
+  // ignore: invalid_runtime_check_with_js_interop_types
   if (dartObject is GeoPointJsImpl) {
     return dartObject as JSAny;
   }
diff --git a/packages/cloud_firestore/cloud_firestore_web/lib/src/utils/decode_utility.dart b/packages/cloud_firestore/cloud_firestore_web/lib/src/utils/decode_utility.dart
index d434466cc64e..132b900a5956 100644
--- a/packages/cloud_firestore/cloud_firestore_web/lib/src/utils/decode_utility.dart
+++ b/packages/cloud_firestore/cloud_firestore_web/lib/src/utils/decode_utility.dart
@@ -13,7 +13,7 @@ import 'package:cloud_firestore_web/src/interop/firestore.dart';
 import '../interop/firestore.dart' as firestore_interop;
 
 /// Class containing static utility methods to decode firestore data.
-class DecodeUtility {
+abstract final class DecodeUtility {
   /// Decodes the values on an incoming Map to their proper types.
   static Map<String, dynamic>? decodeMapData(
       Map<String, dynamic>? data, FirebaseFirestorePlatform firestore) {
@@ -35,14 +35,12 @@ class DecodeUtility {
   /// Decodes an incoming value to its proper type.
   static dynamic valueDecode(
       dynamic value, FirebaseFirestorePlatform firestore) {
-    if (value is JSObject &&
-        value.instanceof(GeoPointConstructor as JSFunction)) {
-      return GeoPoint((value as GeoPointJsImpl).latitude.toDartDouble,
-          (value as GeoPointJsImpl).longitude.toDartDouble);
+    if (value.isA<GeoPointJsImpl>()) {
+      final val = value! as GeoPointJsImpl;
+      return GeoPoint(val.latitude.toDartDouble, val.longitude.toDartDouble);
     } else if (value is DateTime) {
       return Timestamp.fromDate(value);
-    } else if (value is JSObject &&
-        value.instanceof(BytesConstructor as JSFunction)) {
+    } else if (value.isA<BytesJsImpl>()) {
       return Blob((value as BytesJsImpl).toUint8Array().toDart);
     } else if (value is firestore_interop.DocumentReference) {
       return (firestore as FirebaseFirestoreWeb).doc(value.path);
diff --git a/packages/cloud_firestore/cloud_firestore_web/pubspec.yaml b/packages/cloud_firestore/cloud_firestore_web/pubspec.yaml
index ce2e7b3c8a00..7d65ee6dda09 100644
--- a/packages/cloud_firestore/cloud_firestore_web/pubspec.yaml
+++ b/packages/cloud_firestore/cloud_firestore_web/pubspec.yaml
@@ -6,7 +6,7 @@ repository: https://github.com/firebase/flutterfire/tree/master/packages/cloud_f
 version: 3.12.5
 
 environment:
-  sdk: '>=3.2.0 <4.0.0'
+  sdk: ^3.4.0
   flutter: '>=3.3.0'
 
 dependencies:
diff --git a/packages/cloud_functions/cloud_functions_web/lib/interop/functions.dart b/packages/cloud_functions/cloud_functions_web/lib/interop/functions.dart
index a5af9f909b04..70ac693a43e3 100644
--- a/packages/cloud_functions/cloud_functions_web/lib/interop/functions.dart
+++ b/packages/cloud_functions/cloud_functions_web/lib/interop/functions.dart
@@ -89,7 +89,7 @@ class HttpsCallable extends JsObjectWrapper<JSFunction> {
 /// Returns Dart representation from JS Object.
 dynamic _dartify(dynamic object) {
   // Convert JSObject to Dart equivalents directly
-  if (object is! JSObject) {
+  if (object.isA<JSObject>()) {
     return object;
   }
 
diff --git a/packages/cloud_functions/cloud_functions_web/pubspec.yaml b/packages/cloud_functions/cloud_functions_web/pubspec.yaml
index 7dbf51f7df9d..2ee027bdb27b 100644
--- a/packages/cloud_functions/cloud_functions_web/pubspec.yaml
+++ b/packages/cloud_functions/cloud_functions_web/pubspec.yaml
@@ -6,7 +6,7 @@ repository: https://github.com/firebase/flutterfire/tree/master/packages/cloud_f
 version: 4.9.6
 
 environment:
-  sdk: '>=3.2.0 <4.0.0'
+  sdk: ^3.4.0
   flutter: '>=3.3.0'
 
 dependencies:
diff --git a/packages/firebase_analytics/firebase_analytics_web/lib/interop/analytics.dart b/packages/firebase_analytics/firebase_analytics_web/lib/interop/analytics.dart
index a178e700c712..37fcbc24def4 100644
--- a/packages/firebase_analytics/firebase_analytics_web/lib/interop/analytics.dart
+++ b/packages/firebase_analytics/firebase_analytics_web/lib/interop/analytics.dart
@@ -34,7 +34,7 @@ class Analytics extends JsObjectWrapper<analytics_interop.AnalyticsJsImpl> {
 
   static Future<bool> isSupported() async {
     final result = await analytics_interop.isSupported().toDart;
-    return result! as bool;
+    return (result! as JSBoolean).toDart;
   }
 
   /// Non-null App for this instance of analytics service.
diff --git a/packages/firebase_analytics/firebase_analytics_web/pubspec.yaml b/packages/firebase_analytics/firebase_analytics_web/pubspec.yaml
index 473037503889..4867673696b6 100644
--- a/packages/firebase_analytics/firebase_analytics_web/pubspec.yaml
+++ b/packages/firebase_analytics/firebase_analytics_web/pubspec.yaml
@@ -5,7 +5,7 @@ repository: https://github.com/firebase/flutterfire/tree/master/packages/firebas
 version: 0.5.7+7
 
 environment:
-  sdk: '>=3.2.0 <4.0.0'
+  sdk: ^3.4.0
   flutter: '>=3.3.0'
 
 dependencies:
diff --git a/packages/firebase_app_check/firebase_app_check_web/pubspec.yaml b/packages/firebase_app_check/firebase_app_check_web/pubspec.yaml
index 52f802789e03..ee6d21b1fe44 100644
--- a/packages/firebase_app_check/firebase_app_check_web/pubspec.yaml
+++ b/packages/firebase_app_check/firebase_app_check_web/pubspec.yaml
@@ -4,7 +4,7 @@ homepage: https://github.com/firebase/flutterfire/tree/master/packages/firebase_
 version: 0.1.2+7
 
 environment:
-  sdk: '>=3.2.0 <4.0.0'
+  sdk: ^3.4.0
   flutter: '>=3.3.0'
 
 dependencies:
diff --git a/packages/firebase_app_installations/firebase_app_installations_web/pubspec.yaml b/packages/firebase_app_installations/firebase_app_installations_web/pubspec.yaml
index b9dcfe5bf590..942e3ec40189 100644
--- a/packages/firebase_app_installations/firebase_app_installations_web/pubspec.yaml
+++ b/packages/firebase_app_installations/firebase_app_installations_web/pubspec.yaml
@@ -5,7 +5,7 @@ homepage: https://github.com/firebase/flutterfire/tree/master/packages/firebase_
 repository: https://github.com/firebase/flutterfire/tree/master/packages/firebase_app_installations/firebase_app_installations_web
 
 environment:
-  sdk: '>=3.2.0 <4.0.0'
+  sdk: ^3.4.0
   flutter: '>=3.3.0'
 
 dependencies:
diff --git a/packages/firebase_auth/firebase_auth/pubspec.yaml b/packages/firebase_auth/firebase_auth/pubspec.yaml
index 2496268e0f3c..417d6df9824c 100755
--- a/packages/firebase_auth/firebase_auth/pubspec.yaml
+++ b/packages/firebase_auth/firebase_auth/pubspec.yaml
@@ -10,7 +10,7 @@ false_secrets:
   - example/**
 
 environment:
-  sdk: '>=3.2.0 <4.0.0'
+  sdk: ^3.4.0
   flutter: '>=3.16.0'
 
 dependencies:
diff --git a/packages/firebase_auth/firebase_auth_platform_interface/pubspec.yaml b/packages/firebase_auth/firebase_auth_platform_interface/pubspec.yaml
index 4abe29447396..e28f81aea402 100644
--- a/packages/firebase_auth/firebase_auth_platform_interface/pubspec.yaml
+++ b/packages/firebase_auth/firebase_auth_platform_interface/pubspec.yaml
@@ -7,7 +7,7 @@ repository: https://github.com/firebase/flutterfire/tree/master/packages/firebas
 version: 7.3.0
 
 environment:
-  sdk: '>=3.2.0 <4.0.0'
+  sdk: ^3.4.0
   flutter: '>=3.16.0'
 
 dependencies:
diff --git a/packages/firebase_auth/firebase_auth_web/lib/firebase_auth_web.dart b/packages/firebase_auth/firebase_auth_web/lib/firebase_auth_web.dart
index 257e866244cb..0770f522113c 100644
--- a/packages/firebase_auth/firebase_auth_web/lib/firebase_auth_web.dart
+++ b/packages/firebase_auth/firebase_auth_web/lib/firebase_auth_web.dart
@@ -489,8 +489,8 @@ class FirebaseAuthWeb extends FirebaseAuthPlatform {
             .setItem(getOriginName(delegate.app.name), origin);
       }
     } catch (e) {
-      if (e is auth_interop.AuthError) {
-        final String code = e.code.toDart;
+      if ((e as JSObject).isA<auth_interop.AuthError>()) {
+        final String code = (e as auth_interop.AuthError).code.toDart;
         // this catches Firebase Error from web that occurs after hot reloading & hot restarting
         if (code != 'auth/emulator-config-failed') {
           throw getFirebaseAuthException(e);
diff --git a/packages/firebase_auth/firebase_auth_web/lib/src/firebase_auth_web_recaptcha_verifier_factory.dart b/packages/firebase_auth/firebase_auth_web/lib/src/firebase_auth_web_recaptcha_verifier_factory.dart
index 90ea2f89a109..116ba413b75e 100644
--- a/packages/firebase_auth/firebase_auth_web/lib/src/firebase_auth_web_recaptcha_verifier_factory.dart
+++ b/packages/firebase_auth/firebase_auth_web/lib/src/firebase_auth_web_recaptcha_verifier_factory.dart
@@ -154,7 +154,7 @@ class RecaptchaVerifierFactoryWeb extends RecaptchaVerifierFactoryPlatform {
   @override
   Future<int> render() async {
     try {
-      return (await _delegate.render()).toInt();
+      return await _delegate.render();
     } catch (e) {
       throw getFirebaseAuthException(e);
     }
diff --git a/packages/firebase_auth/firebase_auth_web/lib/src/interop/auth.dart b/packages/firebase_auth/firebase_auth_web/lib/src/interop/auth.dart
index 2a4ba442da89..5acfc406fdac 100644
--- a/packages/firebase_auth/firebase_auth_web/lib/src/interop/auth.dart
+++ b/packages/firebase_auth/firebase_auth_web/lib/src/interop/auth.dart
@@ -127,7 +127,7 @@ class User extends UserInfo<auth_interop.UserJsImpl> {
   Future<String> getIdToken([bool forceRefresh = false]) => jsObject
       .getIdToken(forceRefresh.toJS)
       .toDart
-      .then((value) => value! as String);
+      .then((value) => (value! as JSString).toDart);
 
   /// Links the user account with the given credentials, and returns any
   /// available additional user information, such as user name.
@@ -526,7 +526,7 @@ class Auth extends JsObjectWrapper<auth_interop.AuthJsImpl> {
   Future<List<String>> fetchSignInMethodsForEmail(String email) => auth_interop
       .fetchSignInMethodsForEmail(jsObject, email.toJS)
       .toDart
-      .then((value) => List<String>.from(value! as List<dynamic>));
+      .then((value) => List<String>.from((value! as JSArray).toDart));
 
   /// Checks if an incoming link is a sign-in with email link.
   bool isSignInWithEmailLink(String emailLink) =>
@@ -753,7 +753,7 @@ class Auth extends JsObjectWrapper<auth_interop.AuthJsImpl> {
   Future<String> verifyPasswordResetCode(String code) => auth_interop
       .verifyPasswordResetCode(jsObject, code.toJS)
       .toDart
-      .then((value) => value! as String);
+      .then((value) => (value! as JSString).toDart);
 }
 
 /// Represents an auth provider.
@@ -1054,7 +1054,7 @@ class PhoneAuthProvider
       jsObject
           .verifyPhoneNumber(phoneOptions, applicationVerifier.jsObject)
           .toDart
-          .then((value) => value! as String);
+          .then((value) => (value! as JSString).toDart);
 
   /// Creates a phone auth credential given the verification ID
   /// from [verifyPhoneNumber] and the [verificationCode] that was sent to the
@@ -1081,7 +1081,7 @@ abstract class ApplicationVerifier<
   /// Returns a Future containing string for a token that can be used to
   /// assert the validity of a request.
   Future<String> verify() =>
-      jsObject.verify().toDart.then((value) => value! as String);
+      jsObject.verify().toDart.then((value) => (value! as JSString).toDart);
 }
 
 /// reCAPTCHA verifier.
@@ -1137,8 +1137,8 @@ class RecaptchaVerifier
 
   /// Renders the reCAPTCHA widget on the page.
   /// Returns a Future that resolves with the reCAPTCHA widget ID.
-  Future<num> render() =>
-      jsObject.render().toDart.then((value) => value! as num);
+  Future<int> render() =>
+      jsObject.render().toDart.then((value) => (value! as JSNumber).toDartInt);
 }
 
 /// A result from a phone number sign-in, link, or reauthenticate call.
diff --git a/packages/firebase_auth/firebase_auth_web/lib/src/interop/auth_interop.dart b/packages/firebase_auth/firebase_auth_web/lib/src/interop/auth_interop.dart
index 9af18267e88e..9e48ec0756d3 100644
--- a/packages/firebase_auth/firebase_auth_web/lib/src/interop/auth_interop.dart
+++ b/packages/firebase_auth/firebase_auth_web/lib/src/interop/auth_interop.dart
@@ -650,14 +650,10 @@ extension UserProfileExtension on UserProfile {
   external set photoURL(JSString s);
 }
 
-@JS()
-@staticInterop
-abstract class AuthError {}
-
 /// An authentication error.
 ///
 /// See: <https://firebase.google.com/docs/reference/js/firebase.auth.Error>.
-extension AuthErrorExtension on AuthError {
+extension type AuthError(JSObject _) implements JSObject {
   external JSString get code;
   external set code(JSString s);
   external JSString get message;
diff --git a/packages/firebase_auth/firebase_auth_web/pubspec.yaml b/packages/firebase_auth/firebase_auth_web/pubspec.yaml
index b5c221e81385..80f0f409b135 100644
--- a/packages/firebase_auth/firebase_auth_web/pubspec.yaml
+++ b/packages/firebase_auth/firebase_auth_web/pubspec.yaml
@@ -5,7 +5,7 @@ repository: https://github.com/firebase/flutterfire/tree/master/packages/firebas
 version: 5.12.0
 
 environment:
-  sdk: '>=3.2.0 <4.0.0'
+  sdk: ^3.4.0
   flutter: '>=3.16.0'
 
 dependencies:
diff --git a/packages/firebase_core/firebase_core_web/lib/src/firebase_core_web.dart b/packages/firebase_core/firebase_core_web/lib/src/firebase_core_web.dart
index bca05f6a6b25..6bd44d7201c5 100644
--- a/packages/firebase_core/firebase_core_web/lib/src/firebase_core_web.dart
+++ b/packages/firebase_core/firebase_core_web/lib/src/firebase_core_web.dart
@@ -87,8 +87,9 @@ class FirebaseCoreWeb extends FirebasePlatform {
       JSObject? ignored =
           globalContext.getProperty('flutterfire_ignore_scripts'.toJS);
 
-      if (ignored is Iterable) {
-        return (ignored! as Iterable)
+      if (ignored.isA<JSArray>()) {
+        return (ignored! as JSArray)
+            .toDart
             .map((e) => e.toString())
             .toList(growable: false);
       }
diff --git a/packages/firebase_core/firebase_core_web/pubspec.yaml b/packages/firebase_core/firebase_core_web/pubspec.yaml
index 92ad04d83453..fd140e9cf63d 100644
--- a/packages/firebase_core/firebase_core_web/pubspec.yaml
+++ b/packages/firebase_core/firebase_core_web/pubspec.yaml
@@ -5,7 +5,7 @@ repository: https://github.com/firebase/flutterfire/tree/master/packages/firebas
 version: 2.17.0
 
 environment:
-  sdk: '>=3.2.0 <4.0.0'
+  sdk: ^3.4.0
   flutter: '>=3.3.0'
 
 dependencies:
diff --git a/packages/firebase_database/firebase_database_web/pubspec.yaml b/packages/firebase_database/firebase_database_web/pubspec.yaml
index de8013a0ac88..e01dfde5d5a9 100644
--- a/packages/firebase_database/firebase_database_web/pubspec.yaml
+++ b/packages/firebase_database/firebase_database_web/pubspec.yaml
@@ -4,7 +4,7 @@ version: 0.2.5+7
 homepage: https://github.com/firebase/flutterfire/tree/master/packages/firebase_database/firebase_database_web
 
 environment:
-  sdk: '>=3.2.0 <4.0.0'
+  sdk: ^3.4.0
   flutter: '>=3.3.0'
 
 dependencies:
diff --git a/packages/firebase_messaging/firebase_messaging_web/lib/firebase_messaging_web.dart b/packages/firebase_messaging/firebase_messaging_web/lib/firebase_messaging_web.dart
index 8f9d2750cf6b..72ad7c258991 100644
--- a/packages/firebase_messaging/firebase_messaging_web/lib/firebase_messaging_web.dart
+++ b/packages/firebase_messaging/firebase_messaging_web/lib/firebase_messaging_web.dart
@@ -145,7 +145,7 @@ class FirebaseMessagingWeb extends FirebaseMessagingPlatform {
   }) {
     return convertWebExceptions(() async {
       String status =
-          (await web.Notification.requestPermission().toDart) as String;
+         (await web.Notification.requestPermission().toDart).toDart;
       return utils.getNotificationSettings(status);
     });
   }
diff --git a/packages/firebase_messaging/firebase_messaging_web/lib/src/interop/messaging.dart b/packages/firebase_messaging/firebase_messaging_web/lib/src/interop/messaging.dart
index a9d199a5c589..5e8de3c68ad7 100644
--- a/packages/firebase_messaging/firebase_messaging_web/lib/src/interop/messaging.dart
+++ b/packages/firebase_messaging/firebase_messaging_web/lib/src/interop/messaging.dart
@@ -31,8 +31,10 @@ class Messaging extends JsObjectWrapper<messaging_interop.MessagingJsImpl> {
     return _expando[jsObject] ??= Messaging._fromJsObject(jsObject);
   }
 
-  static Future<bool> isSupported() =>
-      messaging_interop.isSupported().toDart.then((value) => value! as bool);
+  static Future<bool> isSupported() => messaging_interop
+      .isSupported()
+      .toDart
+      .then((value) => (value! as JSBoolean).toDart);
 
   Messaging._fromJsObject(messaging_interop.MessagingJsImpl jsObject)
       : super.fromJsObject(jsObject);
@@ -45,13 +47,15 @@ class Messaging extends JsObjectWrapper<messaging_interop.MessagingJsImpl> {
   /// that can be used to send push messages to this user.
   Future<String> getToken({String? vapidKey}) async {
     try {
-      final token = (await messaging_interop
-          .getToken(
-              jsObject,
-              vapidKey == null
-                  ? null
-                  : messaging_interop.GetTokenOptions(vapidKey: vapidKey.toJS))
-          .toDart)! as String;
+      final token = ((await messaging_interop
+              .getToken(
+                  jsObject,
+                  vapidKey == null
+                      ? null
+                      : messaging_interop.GetTokenOptions(
+                          vapidKey: vapidKey.toJS))
+              .toDart)! as JSString)
+          .toDart;
       return token;
     } catch (err) {
       // A race condition can happen in which the service worker get registered
diff --git a/packages/firebase_messaging/firebase_messaging_web/pubspec.yaml b/packages/firebase_messaging/firebase_messaging_web/pubspec.yaml
index e403129c4a27..9e64e92c423f 100644
--- a/packages/firebase_messaging/firebase_messaging_web/pubspec.yaml
+++ b/packages/firebase_messaging/firebase_messaging_web/pubspec.yaml
@@ -5,7 +5,7 @@ repository: https://github.com/firebase/flutterfire/tree/master/packages/firebas
 version: 3.8.7
 
 environment:
-  sdk: '>=3.2.0 <4.0.0'
+  sdk: ^3.4.0
   flutter: '>=3.3.0'
 
 dependencies:
diff --git a/packages/firebase_remote_config/firebase_remote_config_web/lib/src/interop/firebase_remote_config.dart b/packages/firebase_remote_config/firebase_remote_config_web/lib/src/interop/firebase_remote_config.dart
index 569be577a9be..156ef59dc6a3 100644
--- a/packages/firebase_remote_config/firebase_remote_config_web/lib/src/interop/firebase_remote_config.dart
+++ b/packages/firebase_remote_config/firebase_remote_config_web/lib/src/interop/firebase_remote_config.dart
@@ -86,7 +86,7 @@ class RemoteConfig
   Future<bool> activate() async => remote_config_interop
       .activate(jsObject)
       .toDart
-      .then((value) => value! as bool);
+      .then((value) => (value! as JSBoolean).toDart);
 
   ///  Ensures the last activated config are available to the getters.
   Future<void> ensureInitialized() async =>
@@ -101,7 +101,7 @@ class RemoteConfig
   /// If the fetched configs were already activated, the promise will resolve to false.
   Future<bool> fetchAndActivate() async =>
       remote_config_interop.fetchAndActivate(jsObject).toDart.then(
-            (value) => value! as bool,
+            (value) => (value! as JSBoolean).toDart,
           );
 
   /// Returns all config values.
diff --git a/packages/firebase_remote_config/firebase_remote_config_web/pubspec.yaml b/packages/firebase_remote_config/firebase_remote_config_web/pubspec.yaml
index c937048468a5..5e7ad81874fb 100644
--- a/packages/firebase_remote_config/firebase_remote_config_web/pubspec.yaml
+++ b/packages/firebase_remote_config/firebase_remote_config_web/pubspec.yaml
@@ -6,7 +6,7 @@ repository: https://github.com/firebase/flutterfire/tree/master/packages/firebas
 version: 1.6.7
 
 environment:
-  sdk: '>=3.2.0 <4.0.0'
+  sdk: ^3.4.0
   flutter: '>=3.3.0'
 
 dependencies:
diff --git a/packages/firebase_storage/firebase_storage_web/pubspec.yaml b/packages/firebase_storage/firebase_storage_web/pubspec.yaml
index 26ae24e21a41..6070aa0e330a 100644
--- a/packages/firebase_storage/firebase_storage_web/pubspec.yaml
+++ b/packages/firebase_storage/firebase_storage_web/pubspec.yaml
@@ -5,7 +5,7 @@ repository: https://github.com/firebase/flutterfire/tree/master/packages/firebas
 version: 3.9.7
 
 environment:
-  sdk: '>=3.2.0 <4.0.0'
+  sdk: ^3.4.0
   flutter: '>=3.3.0'
 
 dependencies:
diff --git a/packages/firebase_vertexai/firebase_vertexai/example/pubspec.yaml b/packages/firebase_vertexai/firebase_vertexai/example/pubspec.yaml
index e7fd589f84a6..14908bc330c2 100644
--- a/packages/firebase_vertexai/firebase_vertexai/example/pubspec.yaml
+++ b/packages/firebase_vertexai/firebase_vertexai/example/pubspec.yaml
@@ -7,7 +7,7 @@ publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 version: 1.0.0+1
 
 environment:
-  sdk: '>=3.2.0 <4.0.0'
+  sdk: ^3.4.0
 
 # Dependencies specify other packages that your package needs in order to work.
 # To automatically upgrade your package dependencies to the latest versions
diff --git a/packages/firebase_vertexai/firebase_vertexai/pubspec.yaml b/packages/firebase_vertexai/firebase_vertexai/pubspec.yaml
index 65b483e6dc3a..731f1e81d44a 100644
--- a/packages/firebase_vertexai/firebase_vertexai/pubspec.yaml
+++ b/packages/firebase_vertexai/firebase_vertexai/pubspec.yaml
@@ -4,7 +4,7 @@ version: 0.1.1
 homepage: https://firebase.google.com/docs/vertex-ai/get-started?platform=flutter
 
 environment:
-  sdk: '>=3.2.0 <4.0.0'
+  sdk: ^3.4.0
   flutter: ">=3.16.0"
 
 dependencies: