diff --git a/.github/workflows/integration_tests.yml b/.github/workflows/integration_tests.yml
index 3ddaea0630..ef989b70c2 100644
--- a/.github/workflows/integration_tests.yml
+++ b/.github/workflows/integration_tests.yml
@@ -39,6 +39,8 @@ on:
         description: 'Optional: Packaging run # to build against?'
       test_pull_request:
         description: 'Optional: Pull request # to build and test? (With optional commit hash, separated by a colon. Specify the FULL hash.)'
+      firestore_dep_source:
+        description: 'Optional: Where to get firestore iOS SDK from: "RELEASED", "TIP" or "<git-commit> from firestore-ios-sdk"'
 
 env:
   triggerLabelPrefix: "tests-requested: "
@@ -330,6 +332,8 @@ jobs:
           if [[ "${{ github.event.schedule }}" == "0 11 * * *" ]]; then
             # at 3am PST/4am PDT. Running firestore desktop integration test aginst tip-of-tree ios repo
             additional_flags+=(--cmake_flag=-DFIRESTORE_DEP_SOURCE=TIP)
+          elif [[ "${{ github.event.inputs.firestore_dep_source }}" ]]; then
+            additional_flags+=(--cmake_flag=-DFIRESTORE_DEP_SOURCE=${{ github.event.inputs.firestore_dep_source }})
           fi
           python scripts/gha/build_testapps.py --p Desktop \
             --t ${{ needs.check_and_prepare.outputs.apis }} \
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 82a1b8c948..4f3b71301d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -16,7 +16,8 @@
 
 cmake_minimum_required (VERSION 3.1)
 
-set (CMAKE_CXX_STANDARD 11)
+set (CMAKE_CXX_STANDARD 14)
+set (CMAKE_CXX_STANDARD_REQUIRED YES)  # Don't fall back to an earlier version.
 
 # Turn on virtual folders for visual studio
 set_property(GLOBAL PROPERTY USE_FOLDERS ON)
diff --git a/admob/integration_test/CMakeLists.txt b/admob/integration_test/CMakeLists.txt
index d84845c6a9..652f45e7e2 100644
--- a/admob/integration_test/CMakeLists.txt
+++ b/admob/integration_test/CMakeLists.txt
@@ -84,8 +84,9 @@ set(FIREBASE_INTEGRATION_TEST_SRCS
 # The include directory for the testapp.
 include_directories(src)
 
-# Integration test uses some features that require C++ 11, such as lambdas.
-set (CMAKE_CXX_STANDARD 11)
+# Firebase C++ SDK requires C++14.
+set (CMAKE_CXX_STANDARD 14)
+set (CMAKE_CXX_STANDARD_REQUIRED YES)  # Don't fall back to an earlier version.
 
 # Download and unpack googletest (and googlemock) at configure time
 set(GOOGLETEST_ROOT ${CMAKE_CURRENT_LIST_DIR}/external/googletest)
diff --git a/admob/src/include/firebase/admob.h b/admob/src/include/firebase/admob.h
index 3f5acae33d..957c86b7e1 100644
--- a/admob/src/include/firebase/admob.h
+++ b/admob/src/include/firebase/admob.h
@@ -28,7 +28,6 @@
 #include "firebase/admob/rewarded_video.h"
 #include "firebase/admob/types.h"
 #include "firebase/app.h"
-#include "firebase/cpp_version_warning.h"
 #include "firebase/internal/common.h"
 
 #if !defined(DOXYGEN) && !defined(SWIG)
diff --git a/analytics/integration_test/CMakeLists.txt b/analytics/integration_test/CMakeLists.txt
index 6ed6442724..956206969d 100644
--- a/analytics/integration_test/CMakeLists.txt
+++ b/analytics/integration_test/CMakeLists.txt
@@ -84,8 +84,9 @@ set(FIREBASE_INTEGRATION_TEST_SRCS
 # The include directory for the testapp.
 include_directories(src)
 
-# Integration test uses some features that require C++ 11, such as lambdas.
-set (CMAKE_CXX_STANDARD 11)
+# Firebase C++ SDK requires C++14.
+set (CMAKE_CXX_STANDARD 14)
+set (CMAKE_CXX_STANDARD_REQUIRED YES)  # Don't fall back to an earlier version.
 
 # Download and unpack googletest (and googlemock) at configure time
 set(GOOGLETEST_ROOT ${CMAKE_CURRENT_LIST_DIR}/external/googletest)
diff --git a/analytics/src/include/firebase/analytics.h b/analytics/src/include/firebase/analytics.h
index 8fd708e3d5..973890b20f 100644
--- a/analytics/src/include/firebase/analytics.h
+++ b/analytics/src/include/firebase/analytics.h
@@ -23,7 +23,6 @@
 #include <string>
 
 #include "firebase/app.h"
-#include "firebase/cpp_version_warning.h"
 #include "firebase/future.h"
 #include "firebase/internal/common.h"
 #include "firebase/variant.h"
diff --git a/app/CMakeLists.txt b/app/CMakeLists.txt
index 5db0a3f90c..93808bfe71 100644
--- a/app/CMakeLists.txt
+++ b/app/CMakeLists.txt
@@ -251,7 +251,6 @@ endif()
 
 set(internal_HDRS
     src/include/firebase/app.h
-        src/include/firebase/cpp_version_warning.h
     src/include/firebase/future.h
     src/include/firebase/internal/common.h
     src/include/firebase/internal/future_impl.h
diff --git a/app/integration_test/CMakeLists.txt b/app/integration_test/CMakeLists.txt
index f8198474ba..5195f99feb 100644
--- a/app/integration_test/CMakeLists.txt
+++ b/app/integration_test/CMakeLists.txt
@@ -84,8 +84,9 @@ set(FIREBASE_INTEGRATION_TEST_SRCS
 # The include directory for the testapp.
 include_directories(src)
 
-# Integration test uses some features that require C++ 11, such as lambdas.
-set (CMAKE_CXX_STANDARD 11)
+# Firebase C++ SDK requires C++14.
+set (CMAKE_CXX_STANDARD 14)
+set (CMAKE_CXX_STANDARD_REQUIRED YES)  # Don't fall back to an earlier version.
 
 # Download and unpack googletest (and googlemock) at configure time
 set(GOOGLETEST_ROOT ${CMAKE_CURRENT_LIST_DIR}/external/googletest)
diff --git a/app/rest/CMakeLists.txt b/app/rest/CMakeLists.txt
index 50bc08e781..8d58c94f96 100644
--- a/app/rest/CMakeLists.txt
+++ b/app/rest/CMakeLists.txt
@@ -15,7 +15,9 @@
 # CMake file for the firebase_rest_lib library
 
 cmake_minimum_required (VERSION 3.1)
-set (CMAKE_CXX_STANDARD 11)
+# Firebase C++ SDK requires C++14.
+set (CMAKE_CXX_STANDARD 14)
+set (CMAKE_CXX_STANDARD_REQUIRED YES)  # Don't fall back to an earlier version.
 
 project(firebase_rest_lib NONE)
 enable_language(C)
diff --git a/app/src/include/firebase/app.h b/app/src/include/firebase/app.h
index 546ad94fb1..5e7399f8e4 100644
--- a/app/src/include/firebase/app.h
+++ b/app/src/include/firebase/app.h
@@ -17,7 +17,6 @@
 #ifndef FIREBASE_APP_SRC_INCLUDE_FIREBASE_APP_H_
 #define FIREBASE_APP_SRC_INCLUDE_FIREBASE_APP_H_
 
-#include "cpp_version_warning.h"
 #include "firebase/internal/platform.h"
 
 #if FIREBASE_PLATFORM_ANDROID
diff --git a/app/src/include/firebase/cpp_version_warning.h b/app/src/include/firebase/cpp_version_warning.h
deleted file mode 100644
index 2341bf7d82..0000000000
--- a/app/src/include/firebase/cpp_version_warning.h
+++ /dev/null
@@ -1,21 +0,0 @@
-/*
- * Copyright 2023 Google LLC
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#if __cplusplus < 201400
-#pragma message                                            \
-    "The next major release of the Firebase C++ SDK will " \
-    "drop support for C++11, setting the new minimum C++ version to C++14."
-#endif
diff --git a/app_check/integration_test/CMakeLists.txt b/app_check/integration_test/CMakeLists.txt
index 7eb6eb8f3d..9a43ee66f1 100644
--- a/app_check/integration_test/CMakeLists.txt
+++ b/app_check/integration_test/CMakeLists.txt
@@ -84,8 +84,9 @@ set(FIREBASE_INTEGRATION_TEST_SRCS
 # The include directory for the testapp.
 include_directories(src)
 
-# Integration test uses some features that require C++ 11, such as lambdas.
-set (CMAKE_CXX_STANDARD 11)
+# Firebase C++ SDK requires C++14.
+set (CMAKE_CXX_STANDARD 14)
+set (CMAKE_CXX_STANDARD_REQUIRED YES)  # Don't fall back to an earlier version.
 
 # Download and unpack googletest (and googlemock) at configure time
 set(GOOGLETEST_ROOT ${CMAKE_CURRENT_LIST_DIR}/external/googletest)
diff --git a/app_check/src/include/firebase/app_check.h b/app_check/src/include/firebase/app_check.h
index 399fcd1b0c..19167bcf3b 100644
--- a/app_check/src/include/firebase/app_check.h
+++ b/app_check/src/include/firebase/app_check.h
@@ -18,7 +18,6 @@
 #include <string>
 
 #include "firebase/app.h"
-#include "firebase/cpp_version_warning.h"
 #include "firebase/future.h"
 
 namespace firebase {
diff --git a/auth/integration_test/CMakeLists.txt b/auth/integration_test/CMakeLists.txt
index c1b3bbd110..ab5be09e71 100644
--- a/auth/integration_test/CMakeLists.txt
+++ b/auth/integration_test/CMakeLists.txt
@@ -84,8 +84,9 @@ set(FIREBASE_INTEGRATION_TEST_SRCS
 # The include directory for the testapp.
 include_directories(src)
 
-# Integration test uses some features that require C++ 11, such as lambdas.
-set (CMAKE_CXX_STANDARD 11)
+# Firebase C++ SDK requires C++14.
+set (CMAKE_CXX_STANDARD 14)
+set (CMAKE_CXX_STANDARD_REQUIRED YES)  # Don't fall back to an earlier version.
 
 # Download and unpack googletest (and googlemock) at configure time
 set(GOOGLETEST_ROOT ${CMAKE_CURRENT_LIST_DIR}/external/googletest)
diff --git a/auth/src/include/firebase/auth.h b/auth/src/include/firebase/auth.h
index 996a53a362..408c34ea90 100644
--- a/auth/src/include/firebase/auth.h
+++ b/auth/src/include/firebase/auth.h
@@ -21,7 +21,6 @@
 
 #include "firebase/app.h"
 #include "firebase/auth/user.h"
-#include "firebase/cpp_version_warning.h"
 #include "firebase/future.h"
 #include "firebase/internal/common.h"
 
diff --git a/cmake/external/firestore.cmake b/cmake/external/firestore.cmake
index befc2e7dd6..0a835c3bcf 100644
--- a/cmake/external/firestore.cmake
+++ b/cmake/external/firestore.cmake
@@ -49,6 +49,7 @@ function(GetTag t)
     DOWNLOAD_DIR ${FIREBASE_DOWNLOAD_DIR}
     GIT_REPOSITORY "https://github.com/firebase/firebase-ios-sdk.git"
     GIT_TAG ${t}
+    GIT_CONFIG "core.autocrlf=input"
     GIT_SHALLOW "ON"
 
     PREFIX ${PROJECT_BINARY_DIR}
diff --git a/database/integration_test/CMakeLists.txt b/database/integration_test/CMakeLists.txt
index cbc21a8617..4a8cc6f19a 100644
--- a/database/integration_test/CMakeLists.txt
+++ b/database/integration_test/CMakeLists.txt
@@ -84,8 +84,9 @@ set(FIREBASE_INTEGRATION_TEST_SRCS
 # The include directory for the testapp.
 include_directories(src)
 
-# Integration test uses some features that require C++ 11, such as lambdas.
-set (CMAKE_CXX_STANDARD 11)
+# Firebase C++ SDK requires C++14.
+set (CMAKE_CXX_STANDARD 14)
+set (CMAKE_CXX_STANDARD_REQUIRED YES)  # Don't fall back to an earlier version.
 
 # Download and unpack googletest (and googlemock) at configure time
 set(GOOGLETEST_ROOT ${CMAKE_CURRENT_LIST_DIR}/external/googletest)
diff --git a/database/src/include/firebase/database.h b/database/src/include/firebase/database.h
index 2b257df632..d0dc904c10 100644
--- a/database/src/include/firebase/database.h
+++ b/database/src/include/firebase/database.h
@@ -16,7 +16,6 @@
 #define FIREBASE_DATABASE_SRC_INCLUDE_FIREBASE_DATABASE_H_
 
 #include "firebase/app.h"
-#include "firebase/cpp_version_warning.h"
 #include "firebase/database/common.h"
 #include "firebase/database/data_snapshot.h"
 #include "firebase/database/database_reference.h"
diff --git a/dynamic_links/integration_test/CMakeLists.txt b/dynamic_links/integration_test/CMakeLists.txt
index 322eaf6d02..5286ceba8c 100644
--- a/dynamic_links/integration_test/CMakeLists.txt
+++ b/dynamic_links/integration_test/CMakeLists.txt
@@ -84,8 +84,9 @@ set(FIREBASE_INTEGRATION_TEST_SRCS
 # The include directory for the testapp.
 include_directories(src)
 
-# Integration test uses some features that require C++ 11, such as lambdas.
-set (CMAKE_CXX_STANDARD 11)
+# Firebase C++ SDK requires C++14.
+set (CMAKE_CXX_STANDARD 14)
+set (CMAKE_CXX_STANDARD_REQUIRED YES)  # Don't fall back to an earlier version.
 
 # Download and unpack googletest (and googlemock) at configure time
 set(GOOGLETEST_ROOT ${CMAKE_CURRENT_LIST_DIR}/external/googletest)
diff --git a/dynamic_links/src/include/firebase/dynamic_links.h b/dynamic_links/src/include/firebase/dynamic_links.h
index 868c289e30..7a96de679f 100644
--- a/dynamic_links/src/include/firebase/dynamic_links.h
+++ b/dynamic_links/src/include/firebase/dynamic_links.h
@@ -18,7 +18,6 @@
 #include <string>
 
 #include "firebase/app.h"
-#include "firebase/cpp_version_warning.h"
 #include "firebase/internal/common.h"
 
 #if !defined(DOXYGEN) && !defined(SWIG)
diff --git a/firestore/integration_test/CMakeLists.txt b/firestore/integration_test/CMakeLists.txt
index b2351f56f8..af2d1b8150 100644
--- a/firestore/integration_test/CMakeLists.txt
+++ b/firestore/integration_test/CMakeLists.txt
@@ -84,8 +84,9 @@ set(FIREBASE_INTEGRATION_TEST_SRCS
 # The include directory for the testapp.
 include_directories(src)
 
-# Integration test uses some features that require C++ 11, such as lambdas.
-set (CMAKE_CXX_STANDARD 11)
+# Firebase C++ SDK requires C++14.
+set (CMAKE_CXX_STANDARD 14)
+set (CMAKE_CXX_STANDARD_REQUIRED YES)  # Don't fall back to an earlier version.
 
 # Download and unpack googletest (and googlemock) at configure time
 set(GOOGLETEST_ROOT ${CMAKE_CURRENT_LIST_DIR}/external/googletest)
diff --git a/firestore/integration_test_internal/CMakeLists.txt b/firestore/integration_test_internal/CMakeLists.txt
index f6e22bd8b1..5aa57311f3 100644
--- a/firestore/integration_test_internal/CMakeLists.txt
+++ b/firestore/integration_test_internal/CMakeLists.txt
@@ -232,8 +232,9 @@ include_directories(${ABSEIL_CPP_ROOT})
 # Allow testing internal Firebase APIs.
 add_definitions(-DINTERNAL_EXPERIMENTAL)
 
-# Integration test uses some features that require C++ 11, such as lambdas.
-set (CMAKE_CXX_STANDARD 11)
+# Firebase C++ SDK requires C++14.
+set (CMAKE_CXX_STANDARD 14)
+set (CMAKE_CXX_STANDARD_REQUIRED YES)  # Don't fall back to an earlier version.
 
 # Download and unpack googletest (and googlemock) at configure time
 set(GOOGLETEST_ROOT ${CMAKE_CURRENT_LIST_DIR}/external/googletest)
diff --git a/firestore/integration_test_internal/integration_test.xcodeproj/project.pbxproj b/firestore/integration_test_internal/integration_test.xcodeproj/project.pbxproj
index ee3b7df2da..4fc6d0ca75 100644
--- a/firestore/integration_test_internal/integration_test.xcodeproj/project.pbxproj
+++ b/firestore/integration_test_internal/integration_test.xcodeproj/project.pbxproj
@@ -680,7 +680,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "gnu++0x";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++14";
 				CLANG_CXX_LIBRARY = "libc++";
 				CLANG_ENABLE_MODULES = YES;
 				CLANG_ENABLE_OBJC_ARC = YES;
@@ -723,7 +723,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "gnu++0x";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++14";
 				CLANG_CXX_LIBRARY = "libc++";
 				CLANG_ENABLE_MODULES = YES;
 				CLANG_ENABLE_OBJC_ARC = YES;
diff --git a/firestore/integration_test_internal/src/android/promise_android_test.cc b/firestore/integration_test_internal/src/android/promise_android_test.cc
index 96615a729d..f5503f4e88 100644
--- a/firestore/integration_test_internal/src/android/promise_android_test.cc
+++ b/firestore/integration_test_internal/src/android/promise_android_test.cc
@@ -31,7 +31,6 @@
 #include "firestore/src/android/exception_android.h"
 #include "firestore/src/android/firestore_android.h"
 #include "firestore/src/android/promise_factory_android.h"
-#include "firestore/src/common/make_unique.h"
 #include "firestore/src/include/firebase/firestore.h"
 #include "firestore/src/jni/env.h"
 #include "firestore/src/jni/integer.h"
@@ -210,7 +209,7 @@ class TestCompletion : public TestCompletionBase<PublicType, InternalType> {
     if (result == nullptr) {
       result_.reset(nullptr);
     } else {
-      result_ = make_unique<PublicType>(*result);
+      result_ = std::make_unique<PublicType>(*result);
     }
   }
 
diff --git a/firestore/integration_test_internal/src/jni/env_test.cc b/firestore/integration_test_internal/src/jni/env_test.cc
index d31992e48e..9e5f04d50f 100644
--- a/firestore/integration_test_internal/src/jni/env_test.cc
+++ b/firestore/integration_test_internal/src/jni/env_test.cc
@@ -22,7 +22,6 @@
 #include "app/meta/move.h"
 #include "firestore/src/android/exception_android.h"
 #include "firestore/src/common/macros.h"
-#include "firestore/src/common/make_unique.h"
 #include "firestore/src/jni/array.h"
 #include "firestore_integration_test.h"
 #include "gtest/gtest.h"
@@ -33,7 +32,7 @@ namespace jni {
 
 class EnvTest : public FirestoreIntegrationTest {
  public:
-  EnvTest() : env_(make_unique<Env>(GetEnv())) {}
+  EnvTest() : env_(std::make_unique<Env>(GetEnv())) {}
 
   ~EnvTest() override {
     // Ensure that after the test is done that any pending exception is cleared
diff --git a/firestore/integration_test_internal/src/util/integration_test_util.cc b/firestore/integration_test_internal/src/util/integration_test_util.cc
index d16dc418d3..3746d0faf4 100644
--- a/firestore/integration_test_internal/src/util/integration_test_util.cc
+++ b/firestore/integration_test_internal/src/util/integration_test_util.cc
@@ -15,9 +15,9 @@
  */
 
 #include <chrono>  // NOLINT(build/c++11)
+#include <memory>
 #include <thread>  // NOLINT(build/c++11)
 
-#include "absl/memory/memory.h"
 #include "app_framework.h"
 #include "firebase/app.h"
 #include "firebase/firestore.h"
@@ -37,8 +37,8 @@ struct TestFriend {
   static FirestoreInternal* CreateTestFirestoreInternal(App* app) {
 #if !defined(__ANDROID__)
     return new FirestoreInternal(
-        app, absl::make_unique<credentials::EmptyAuthCredentialsProvider>(),
-        absl::make_unique<credentials::EmptyAppCheckCredentialsProvider>());
+        app, std::make_unique<credentials::EmptyAuthCredentialsProvider>(),
+        std::make_unique<credentials::EmptyAppCheckCredentialsProvider>());
 #else
     return new FirestoreInternal(app);
 #endif  // !defined(__ANDROID__)
diff --git a/firestore/src/android/firestore_android.cc b/firestore/src/android/firestore_android.cc
index 4b9926ce09..4c0e2a990c 100644
--- a/firestore/src/android/firestore_android.cc
+++ b/firestore/src/android/firestore_android.cc
@@ -60,7 +60,6 @@
 #include "firestore/src/android/wrapper.h"
 #include "firestore/src/android/write_batch_android.h"
 #include "firestore/src/common/hard_assert_common.h"
-#include "firestore/src/common/make_unique.h"
 #include "firestore/src/include/firebase/firestore.h"
 #include "firestore/src/jni/array.h"
 #include "firestore/src/jni/array_list.h"
@@ -285,7 +284,7 @@ FirestoreInternal::FirestoreInternal(App* app) {
   FIREBASE_ASSERT(java_user_callback_executor.get() != nullptr);
   user_callback_executor_ = java_user_callback_executor;
 
-  promises_ = make_unique<PromiseFactory<AsyncFn>>(this);
+  promises_ = std::make_unique<PromiseFactory<AsyncFn>>(this);
 }
 
 /* static */
diff --git a/firestore/src/android/promise_android.h b/firestore/src/android/promise_android.h
index b1f9c6ec5e..04131651e3 100644
--- a/firestore/src/android/promise_android.h
+++ b/firestore/src/android/promise_android.h
@@ -28,7 +28,6 @@
 #include "firestore/src/android/exception_android.h"
 #include "firestore/src/android/firestore_android.h"
 #include "firestore/src/android/query_snapshot_android.h"
-#include "firestore/src/common/make_unique.h"
 #include "firestore/src/jni/env.h"
 #include "firestore/src/jni/object.h"
 #include "firestore/src/jni/task.h"
@@ -98,7 +97,7 @@ class Promise {
           ReferenceCountedFutureImpl* impl,
           Completion* completion)
       : firestore_ref_(firestore_ref),
-        completer_(make_unique<Completer<PublicType, InternalType>>(
+        completer_(std::make_unique<Completer<PublicType, InternalType>>(
             firestore_ref, impl, completion)),
         impl_(impl) {}
 
diff --git a/firestore/src/common/make_unique.h b/firestore/src/common/make_unique.h
deleted file mode 100644
index 0098017076..0000000000
--- a/firestore/src/common/make_unique.h
+++ /dev/null
@@ -1,37 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-// Note: This is needed since std::make_unique is only available starting C++14.
-// TODO(b/191981857): Remove this file when possible.
-
-#ifndef FIREBASE_FIRESTORE_SRC_COMMON_MAKE_UNIQUE_H_
-#define FIREBASE_FIRESTORE_SRC_COMMON_MAKE_UNIQUE_H_
-
-#include <memory>
-#include <utility>
-
-namespace firebase {
-namespace firestore {
-
-template <typename T, typename... Args>
-std::unique_ptr<T> make_unique(Args&&... args) {
-  return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
-}
-
-}  // namespace firestore
-}  // namespace firebase
-
-#endif  // FIREBASE_FIRESTORE_SRC_COMMON_MAKE_UNIQUE_H_
diff --git a/firestore/src/common/settings_apple.mm b/firestore/src/common/settings_apple.mm
index 57856d16fc..5ff4b325df 100644
--- a/firestore/src/common/settings_apple.mm
+++ b/firestore/src/common/settings_apple.mm
@@ -17,9 +17,9 @@
 #include "firestore/src/include/firebase/firestore/settings.h"
 
 #include <dispatch/dispatch.h>
+#include <memory>
 
 #include "Firestore/core/src/util/executor_libdispatch.h"
-#include "absl/memory/memory.h"
 
 namespace firebase {
 namespace firestore {
@@ -39,7 +39,7 @@
           Executor::CreateSerial("com.google.firebase.firestore.callback")) {}
 
 std::unique_ptr<Executor> Settings::CreateExecutor() const {
-  return absl::make_unique<ExecutorLibdispatch>(dispatch_queue());
+  return std::make_unique<ExecutorLibdispatch>(dispatch_queue());
 }
 
 dispatch_queue_t Settings::dispatch_queue() const {
@@ -52,7 +52,7 @@
 }
 
 void Settings::set_dispatch_queue(dispatch_queue_t queue) {
-  executor_ = absl::make_unique<ExecutorLibdispatch>(queue);
+  executor_ = std::make_unique<ExecutorLibdispatch>(queue);
 }
 
 }  // namespace firestore
diff --git a/firestore/src/include/firebase/firestore.h b/firestore/src/include/firebase/firestore.h
index d8a461e7b2..1749a4e3b2 100644
--- a/firestore/src/include/firebase/firestore.h
+++ b/firestore/src/include/firebase/firestore.h
@@ -23,7 +23,6 @@
 #include "firebase/internal/common.h"
 
 #include "firebase/app.h"
-#include "firebase/cpp_version_warning.h"
 #include "firebase/future.h"
 #include "firebase/log.h"
 // Include *all* the public headers to make sure including just "firestore.h" is
diff --git a/firestore/src/main/create_credentials_provider_desktop.cc b/firestore/src/main/create_credentials_provider_desktop.cc
index 1a10375383..fac9e68afb 100644
--- a/firestore/src/main/create_credentials_provider_desktop.cc
+++ b/firestore/src/main/create_credentials_provider_desktop.cc
@@ -14,7 +14,8 @@
  * limitations under the License.
  */
 
-#include "absl/memory/memory.h"
+#include <memory>
+
 #include "auth/src/include/firebase/auth.h"
 #include "firestore/src/main/create_credentials_provider.h"
 #include "firestore/src/main/credentials_provider_desktop.h"
@@ -26,7 +27,7 @@ using credentials::AuthCredentialsProvider;
 using firebase::auth::Auth;
 
 std::unique_ptr<AuthCredentialsProvider> CreateCredentialsProvider(App& app) {
-  return absl::make_unique<FirebaseCppCredentialsProvider>(app);
+  return std::make_unique<FirebaseCppCredentialsProvider>(app);
 }
 
 }  // namespace firestore
diff --git a/firestore/src/main/create_credentials_provider_ios.mm b/firestore/src/main/create_credentials_provider_ios.mm
index 8b5c35cc12..abbf74c5b2 100644
--- a/firestore/src/main/create_credentials_provider_ios.mm
+++ b/firestore/src/main/create_credentials_provider_ios.mm
@@ -16,6 +16,8 @@
 
 #include "firestore/src/main/create_credentials_provider.h"
 
+#include <memory>
+
 #import "FIRAppInternal.h"
 #import "FIRAuthInterop.h"
 #import "FIRComponent.h"
@@ -24,7 +26,6 @@
 #import "FirebaseCore.h"
 
 #include "Firestore/core/src/credentials/firebase_auth_credentials_provider_apple.h"
-#include "absl/memory/memory.h"
 #include "app/src/include/firebase/app.h"
 
 namespace firebase {
@@ -36,7 +37,7 @@
 std::unique_ptr<AuthCredentialsProvider> CreateCredentialsProvider(App& app) {
   FIRApp* ios_app = app.GetPlatformApp();
   auto ios_auth = FIR_COMPONENT(FIRAuthInterop, ios_app.container);
-  return absl::make_unique<FirebaseAuthCredentialsProvider>(ios_app, ios_auth);
+  return std::make_unique<FirebaseAuthCredentialsProvider>(ios_app, ios_auth);
 }
 
 }  // namespace firestore
diff --git a/firestore/src/main/create_firebase_metadata_provider_desktop.cc b/firestore/src/main/create_firebase_metadata_provider_desktop.cc
index a6daace69c..f8d0724b4e 100644
--- a/firestore/src/main/create_firebase_metadata_provider_desktop.cc
+++ b/firestore/src/main/create_firebase_metadata_provider_desktop.cc
@@ -14,7 +14,8 @@
  * limitations under the License.
  */
 
-#include "absl/memory/memory.h"
+#include <memory>
+
 #include "firestore/src/main/create_firebase_metadata_provider.h"
 #include "firestore/src/main/firebase_metadata_provider_desktop.h"
 
@@ -25,7 +26,7 @@ using remote::FirebaseMetadataProvider;
 
 std::unique_ptr<FirebaseMetadataProvider> CreateFirebaseMetadataProvider(
     App& app) {
-  return absl::make_unique<FirebaseMetadataProviderCpp>(app);
+  return std::make_unique<FirebaseMetadataProviderCpp>(app);
 }
 
 }  // namespace firestore
diff --git a/firestore/src/main/create_firebase_metadata_provider_ios.mm b/firestore/src/main/create_firebase_metadata_provider_ios.mm
index 1161bcb836..556c565a17 100644
--- a/firestore/src/main/create_firebase_metadata_provider_ios.mm
+++ b/firestore/src/main/create_firebase_metadata_provider_ios.mm
@@ -16,8 +16,9 @@
 
 #include "firestore/src/main/create_firebase_metadata_provider.h"
 
+#include <memory>
+
 #include "Firestore/core/src/remote/firebase_metadata_provider_apple.h"
-#include "absl/memory/memory.h"
 #include "app/src/include/firebase/app.h"
 
 namespace firebase {
@@ -28,7 +29,7 @@
 
 std::unique_ptr<FirebaseMetadataProvider> CreateFirebaseMetadataProvider(
     App& app) {
-  return absl::make_unique<FirebaseMetadataProviderApple>(app.GetPlatformApp());
+  return std::make_unique<FirebaseMetadataProviderApple>(app.GetPlatformApp());
 }
 
 }  // namespace firestore
diff --git a/firestore/src/main/firestore_main.cc b/firestore/src/main/firestore_main.cc
index 3834ec6a8d..1616e34534 100644
--- a/firestore/src/main/firestore_main.cc
+++ b/firestore/src/main/firestore_main.cc
@@ -17,6 +17,7 @@
 #include "firestore/src/main/firestore_main.h"
 
 #include <cstring>
+#include <memory>
 #include <sstream>
 #include <utility>
 
@@ -387,8 +388,8 @@ Future<LoadBundleTaskProgress> FirestoreInternal::LoadBundle(
     const std::string& bundle) {
   auto promise = promise_factory_.CreatePromise<LoadBundleTaskProgress>(
       AsyncApi::kLoadBundle);
-  auto bundle_stream = absl::make_unique<util::ByteStreamCpp>(
-      absl::make_unique<std::stringstream>(bundle));
+  auto bundle_stream = std::make_unique<util::ByteStreamCpp>(
+      std::make_unique<std::stringstream>(bundle));
 
   std::shared_ptr<api::LoadBundleTask> task =
       firestore_core_->LoadBundle(std::move(bundle_stream));
@@ -412,8 +413,8 @@ Future<LoadBundleTaskProgress> FirestoreInternal::LoadBundle(
     std::function<void(const LoadBundleTaskProgress&)> progress_callback) {
   auto promise = promise_factory_.CreatePromise<LoadBundleTaskProgress>(
       AsyncApi::kLoadBundle);
-  auto bundle_stream = absl::make_unique<util::ByteStreamCpp>(
-      absl::make_unique<std::stringstream>(bundle));
+  auto bundle_stream = std::make_unique<util::ByteStreamCpp>(
+      std::make_unique<std::stringstream>(bundle));
 
   std::shared_ptr<api::LoadBundleTask> task =
       firestore_core_->LoadBundle(std::move(bundle_stream));
diff --git a/functions/integration_test/CMakeLists.txt b/functions/integration_test/CMakeLists.txt
index a220e558aa..dccb88cd50 100644
--- a/functions/integration_test/CMakeLists.txt
+++ b/functions/integration_test/CMakeLists.txt
@@ -84,8 +84,9 @@ set(FIREBASE_INTEGRATION_TEST_SRCS
 # The include directory for the testapp.
 include_directories(src)
 
-# Integration test uses some features that require C++ 11, such as lambdas.
-set (CMAKE_CXX_STANDARD 11)
+# Firebase C++ SDK requires C++14.
+set (CMAKE_CXX_STANDARD 14)
+set (CMAKE_CXX_STANDARD_REQUIRED YES)  # Don't fall back to an earlier version.
 
 # Download and unpack googletest (and googlemock) at configure time
 set(GOOGLETEST_ROOT ${CMAKE_CURRENT_LIST_DIR}/external/googletest)
diff --git a/functions/src/include/firebase/functions.h b/functions/src/include/firebase/functions.h
index b7aa0259c2..500a05cc7a 100644
--- a/functions/src/include/firebase/functions.h
+++ b/functions/src/include/firebase/functions.h
@@ -18,7 +18,6 @@
 #include <string>
 
 #include "firebase/app.h"
-#include "firebase/cpp_version_warning.h"
 #include "firebase/functions/callable_reference.h"
 #include "firebase/functions/callable_result.h"
 #include "firebase/functions/common.h"
diff --git a/gma/integration_test/CMakeLists.txt b/gma/integration_test/CMakeLists.txt
index a4825bdd1e..29c6a6e4d1 100644
--- a/gma/integration_test/CMakeLists.txt
+++ b/gma/integration_test/CMakeLists.txt
@@ -84,8 +84,9 @@ set(FIREBASE_INTEGRATION_TEST_SRCS
 # The include directory for the testapp.
 include_directories(src)
 
-# Integration test uses some features that require C++ 11, such as lambdas.
-set (CMAKE_CXX_STANDARD 11)
+# Firebase C++ SDK requires C++14.
+set (CMAKE_CXX_STANDARD 14)
+set (CMAKE_CXX_STANDARD_REQUIRED YES)  # Don't fall back to an earlier version.
 
 # Download and unpack googletest (and googlemock) at configure time
 set(GOOGLETEST_ROOT ${CMAKE_CURRENT_LIST_DIR}/external/googletest)
diff --git a/gma/src/include/firebase/gma.h b/gma/src/include/firebase/gma.h
index 9a4644b191..b7da2cf569 100644
--- a/gma/src/include/firebase/gma.h
+++ b/gma/src/include/firebase/gma.h
@@ -26,7 +26,6 @@
 #include <vector>
 
 #include "firebase/app.h"
-#include "firebase/cpp_version_warning.h"
 #include "firebase/gma/ad_view.h"
 #include "firebase/gma/interstitial_ad.h"
 #include "firebase/gma/rewarded_ad.h"
diff --git a/installations/integration_test/CMakeLists.txt b/installations/integration_test/CMakeLists.txt
index e0cb95f201..1bc9bc879e 100644
--- a/installations/integration_test/CMakeLists.txt
+++ b/installations/integration_test/CMakeLists.txt
@@ -84,8 +84,9 @@ set(FIREBASE_INTEGRATION_TEST_SRCS
 # The include directory for the testapp.
 include_directories(src)
 
-# Integration test uses some features that require C++ 11, such as lambdas.
-set (CMAKE_CXX_STANDARD 11)
+# Firebase C++ SDK requires C++14.
+set (CMAKE_CXX_STANDARD 14)
+set (CMAKE_CXX_STANDARD_REQUIRED YES)  # Don't fall back to an earlier version.
 
 # Download and unpack googletest (and googlemock) at configure time
 set(GOOGLETEST_ROOT ${CMAKE_CURRENT_LIST_DIR}/external/googletest)
diff --git a/installations/src/include/firebase/installations.h b/installations/src/include/firebase/installations.h
index 0cd1a14615..c9774bc37e 100644
--- a/installations/src/include/firebase/installations.h
+++ b/installations/src/include/firebase/installations.h
@@ -19,7 +19,6 @@
 #include <string>
 
 #include "firebase/app.h"
-#include "firebase/cpp_version_warning.h"
 #include "firebase/future.h"
 #include "firebase/internal/common.h"
 
diff --git a/messaging/integration_test/CMakeLists.txt b/messaging/integration_test/CMakeLists.txt
index cb38e1f31e..3e33aa9bea 100644
--- a/messaging/integration_test/CMakeLists.txt
+++ b/messaging/integration_test/CMakeLists.txt
@@ -84,8 +84,9 @@ set(FIREBASE_INTEGRATION_TEST_SRCS
 # The include directory for the testapp.
 include_directories(src)
 
-# Integration test uses some features that require C++ 11, such as lambdas.
-set (CMAKE_CXX_STANDARD 11)
+# Firebase C++ SDK requires C++14.
+set (CMAKE_CXX_STANDARD 14)
+set (CMAKE_CXX_STANDARD_REQUIRED YES)  # Don't fall back to an earlier version.
 
 # Download and unpack googletest (and googlemock) at configure time
 set(GOOGLETEST_ROOT ${CMAKE_CURRENT_LIST_DIR}/external/googletest)
diff --git a/messaging/src/include/firebase/messaging.h b/messaging/src/include/firebase/messaging.h
index bda6abd6f2..e7c7f57768 100644
--- a/messaging/src/include/firebase/messaging.h
+++ b/messaging/src/include/firebase/messaging.h
@@ -22,7 +22,6 @@
 #include <vector>
 
 #include "firebase/app.h"
-#include "firebase/cpp_version_warning.h"
 #include "firebase/future.h"
 #include "firebase/internal/common.h"
 
diff --git a/performance/src/include/firebase/performance.h b/performance/src/include/firebase/performance.h
index 0ccf6d4d7b..ee7acaeec4 100644
--- a/performance/src/include/firebase/performance.h
+++ b/performance/src/include/firebase/performance.h
@@ -4,7 +4,6 @@
 #define FIREBASE_PERFORMANCE_SRC_INCLUDE_FIREBASE_PERFORMANCE_H_
 
 #include "firebase/app.h"
-#include "firebase/cpp_version_warning.h"
 #include "firebase/performance/http_metric.h"
 #include "firebase/performance/trace.h"
 
diff --git a/release_build_files/readme.md b/release_build_files/readme.md
index a3372bb0d7..029eb59477 100644
--- a/release_build_files/readme.md
+++ b/release_build_files/readme.md
@@ -70,11 +70,9 @@ libs/windows              | Windows static libraries (desktop or stub
 
 ## C++ Language Standards
 
-The Firebase C++ SDK supports the C++11 language standard.
-
-Note: The next major release of the Firebase C++ SDK will set the new minimum
-C++ version to C++14. For more information please see our
-[C++ Language Standard Support Criteria](https://opensource.google/documentation/policies/cplusplus-support#c_language_standard).
+The Firebase C++ SDK supports the C++14 language standard. For more information,
+please see our [C++ Language Standard Support
+Criteria](https://opensource.google/documentation/policies/cplusplus-support#c_language_standard).
 
 ## Library / XCFramework Dependencies
 
@@ -644,6 +642,7 @@ code.
 ## Release Notes
 ### Upcoming Release
 -   Changes
+    - General: Update minimum supported C++ standard to C++14.
     - General (iOS): Update to Firebase Cocoapods version 10.8.0.
     - General (Android): Update to Firebase Android BoM version 31.5.0.
     - GMA (Android): Updated dependency to play-services-ads version 22.0.0.
diff --git a/remote_config/integration_test/CMakeLists.txt b/remote_config/integration_test/CMakeLists.txt
index 828e6f23ae..3b61f6f729 100644
--- a/remote_config/integration_test/CMakeLists.txt
+++ b/remote_config/integration_test/CMakeLists.txt
@@ -84,8 +84,9 @@ set(FIREBASE_INTEGRATION_TEST_SRCS
 # The include directory for the testapp.
 include_directories(src)
 
-# Integration test uses some features that require C++ 11, such as lambdas.
-set (CMAKE_CXX_STANDARD 11)
+# Firebase C++ SDK requires C++14.
+set (CMAKE_CXX_STANDARD 14)
+set (CMAKE_CXX_STANDARD_REQUIRED YES)  # Don't fall back to an earlier version.
 
 # Download and unpack googletest (and googlemock) at configure time
 set(GOOGLETEST_ROOT ${CMAKE_CURRENT_LIST_DIR}/external/googletest)
diff --git a/remote_config/src/include/firebase/remote_config.h b/remote_config/src/include/firebase/remote_config.h
index f201d23ee2..a2bd417757 100644
--- a/remote_config/src/include/firebase/remote_config.h
+++ b/remote_config/src/include/firebase/remote_config.h
@@ -20,7 +20,6 @@
 #include <vector>
 
 #include "firebase/app.h"
-#include "firebase/cpp_version_warning.h"
 #include "firebase/future.h"
 #include "firebase/internal/common.h"
 #include "firebase/internal/platform.h"
diff --git a/storage/integration_test/CMakeLists.txt b/storage/integration_test/CMakeLists.txt
index f2eea4ad79..71011b2138 100644
--- a/storage/integration_test/CMakeLists.txt
+++ b/storage/integration_test/CMakeLists.txt
@@ -84,8 +84,9 @@ set(FIREBASE_INTEGRATION_TEST_SRCS
 # The include directory for the testapp.
 include_directories(src)
 
-# Integration test uses some features that require C++ 11, such as lambdas.
-set (CMAKE_CXX_STANDARD 11)
+# Firebase C++ SDK requires C++14.
+set (CMAKE_CXX_STANDARD 14)
+set (CMAKE_CXX_STANDARD_REQUIRED YES)  # Don't fall back to an earlier version.
 
 # Download and unpack googletest (and googlemock) at configure time
 set(GOOGLETEST_ROOT ${CMAKE_CURRENT_LIST_DIR}/external/googletest)
diff --git a/storage/src/include/firebase/storage.h b/storage/src/include/firebase/storage.h
index e113e2bd25..8d081e4c0e 100644
--- a/storage/src/include/firebase/storage.h
+++ b/storage/src/include/firebase/storage.h
@@ -18,7 +18,6 @@
 #include <string>
 
 #include "firebase/app.h"
-#include "firebase/cpp_version_warning.h"
 #include "firebase/internal/common.h"
 #include "firebase/storage/common.h"
 #include "firebase/storage/controller.h"
diff --git a/testing/CMakeLists.txt b/testing/CMakeLists.txt
index 2bde9285ba..9f3817fbf3 100644
--- a/testing/CMakeLists.txt
+++ b/testing/CMakeLists.txt
@@ -13,7 +13,8 @@
 # limitations under the License.
 
 cmake_minimum_required (VERSION 3.1)
-set (CMAKE_CXX_STANDARD 11)
+set (CMAKE_CXX_STANDARD 14)
+set (CMAKE_CXX_STANDARD_REQUIRED YES)  # Don't fall back to an earlier version.
 
 include(binary_to_array)
 
diff --git a/testlab/src/include/firebase/testlab.h b/testlab/src/include/firebase/testlab.h
index 6fa9b15156..6dfdd95732 100644
--- a/testlab/src/include/firebase/testlab.h
+++ b/testlab/src/include/firebase/testlab.h
@@ -20,7 +20,6 @@
 #include <string>
 
 #include "firebase/app.h"
-#include "firebase/cpp_version_warning.h"
 #include "firebase/internal/common.h"
 
 #if !defined(DOXYGEN) && !defined(SWIG)