diff --git a/ash/components/arc/net/arc_net_utils_unittest.cc b/ash/components/arc/net/arc_net_utils_unittest.cc
index c1d8a745261fb..745d1fdfad10e 100644
--- a/ash/components/arc/net/arc_net_utils_unittest.cc
+++ b/ash/components/arc/net/arc_net_utils_unittest.cc
@@ -7,7 +7,6 @@
 #include <memory>
 #include <string>
 
-#include "base/sys_byteorder.h"
 #include "base/test/task_environment.h"
 #include "chromeos/ash/components/network/device_state.h"
 #include "chromeos/ash/components/network/network_state_test_helper.h"
diff --git a/base/big_endian.h b/base/big_endian.h
index 1a42bd0708cbc..748a01c26b3a1 100644
--- a/base/big_endian.h
+++ b/base/big_endian.h
@@ -17,8 +17,6 @@
 #include "base/containers/span.h"
 #include "base/memory/raw_span.h"
 #include "base/strings/string_piece.h"
-#include "base/sys_byteorder.h"
-#include "build/build_config.h"
 
 namespace base {
 
diff --git a/chrome/browser/metrics/chromeos_metrics_provider.cc b/chrome/browser/metrics/chromeos_metrics_provider.cc
index dac28ee79830d..4b811542c31d9 100644
--- a/chrome/browser/metrics/chromeos_metrics_provider.cc
+++ b/chrome/browser/metrics/chromeos_metrics_provider.cc
@@ -23,7 +23,6 @@
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
-#include "base/sys_byteorder.h"
 #include "base/task/task_traits.h"
 #include "base/task/thread_pool.h"
 #include "chrome/browser/ash/accessibility/accessibility_manager.h"
diff --git a/chrome/browser/webauthn/android/cable_module_android.cc b/chrome/browser/webauthn/android/cable_module_android.cc
index cc4c82f3c68c8..06024e1d37fbd 100644
--- a/chrome/browser/webauthn/android/cable_module_android.cc
+++ b/chrome/browser/webauthn/android/cable_module_android.cc
@@ -10,7 +10,6 @@
 #include "base/logging.h"
 #include "base/memory/raw_ptr_exclusion.h"
 #include "base/no_destructor.h"
-#include "base/sys_byteorder.h"
 #include "base/task/task_traits.h"
 #include "base/task/thread_pool.h"
 #include "chrome/browser/browser_process.h"
diff --git a/chrome/browser/webauthn/chrome_authenticator_request_delegate.cc b/chrome/browser/webauthn/chrome_authenticator_request_delegate.cc
index 76b1cea6861bf..758cfd177d77a 100644
--- a/chrome/browser/webauthn/chrome_authenticator_request_delegate.cc
+++ b/chrome/browser/webauthn/chrome_authenticator_request_delegate.cc
@@ -20,7 +20,6 @@
 #include "base/memory/raw_ptr.h"
 #include "base/ranges/algorithm.h"
 #include "base/strings/string_split.h"
-#include "base/sys_byteorder.h"
 #include "base/task/thread_pool.h"
 #include "base/values.h"
 #include "build/build_config.h"
diff --git a/chrome/services/sharing/webrtc/ipc_network_manager.cc b/chrome/services/sharing/webrtc/ipc_network_manager.cc
index 17fa3ca146b44..68b1e64d8bdb0 100644
--- a/chrome/services/sharing/webrtc/ipc_network_manager.cc
+++ b/chrome/services/sharing/webrtc/ipc_network_manager.cc
@@ -10,7 +10,6 @@
 
 #include "base/functional/bind.h"
 #include "base/location.h"
-#include "base/sys_byteorder.h"
 #include "base/task/single_thread_task_runner.h"
 #include "components/webrtc/net_address_utils.h"
 #include "net/base/ip_address.h"
diff --git a/components/gcm_driver/crypto/gcm_message_cryptographer.cc b/components/gcm_driver/crypto/gcm_message_cryptographer.cc
index 5387ba45d5342..31a5803d8979a 100644
--- a/components/gcm_driver/crypto/gcm_message_cryptographer.cc
+++ b/components/gcm_driver/crypto/gcm_message_cryptographer.cc
@@ -18,7 +18,6 @@
 #include "base/numerics/safe_conversions.h"
 #include "base/numerics/safe_math.h"
 #include "base/strings/strcat.h"
-#include "base/sys_byteorder.h"
 #include "crypto/hkdf.h"
 #include "third_party/boringssl/src/include/openssl/aead.h"
 
diff --git a/components/gcm_driver/fake_gcm_client.cc b/components/gcm_driver/fake_gcm_client.cc
index d21235a39a907..33c0f36eba5c5 100644
--- a/components/gcm_driver/fake_gcm_client.cc
+++ b/components/gcm_driver/fake_gcm_client.cc
@@ -12,7 +12,6 @@
 #include "base/functional/bind.h"
 #include "base/location.h"
 #include "base/strings/string_number_conversions.h"
-#include "base/sys_byteorder.h"
 #include "base/task/sequenced_task_runner.h"
 #include "base/task/single_thread_task_runner.h"
 #include "base/time/time.h"
diff --git a/components/media_router/common/providers/cast/channel/cast_socket.cc b/components/media_router/common/providers/cast/channel/cast_socket.cc
index bb66bf8604b5e..9b77c81bd8674 100644
--- a/components/media_router/common/providers/cast/channel/cast_socket.cc
+++ b/components/media_router/common/providers/cast/channel/cast_socket.cc
@@ -19,7 +19,6 @@
 #include "base/numerics/safe_conversions.h"
 #include "base/observer_list.h"
 #include "base/strings/string_number_conversions.h"
-#include "base/sys_byteorder.h"
 #include "base/task/single_thread_task_runner.h"
 #include "base/time/time.h"
 #include "components/media_router/common/providers/cast/channel/cast_auth_util.h"
diff --git a/components/media_router/common/providers/cast/channel/cast_socket_unittest.cc b/components/media_router/common/providers/cast/channel/cast_socket_unittest.cc
index 0e2313b10ae72..bd8cedef745de 100644
--- a/components/media_router/common/providers/cast/channel/cast_socket_unittest.cc
+++ b/components/media_router/common/providers/cast/channel/cast_socket_unittest.cc
@@ -20,7 +20,6 @@
 #include "base/path_service.h"
 #include "base/run_loop.h"
 #include "base/strings/string_number_conversions.h"
-#include "base/sys_byteorder.h"
 #include "base/task/single_thread_task_runner.h"
 #include "base/test/bind.h"
 #include "base/timer/mock_timer.h"
diff --git a/components/policy/core/common/policy_loader_win_unittest.cc b/components/policy/core/common/policy_loader_win_unittest.cc
index 8a1fe1ecaa4df..ea8ad18322dfa 100644
--- a/components/policy/core/common/policy_loader_win_unittest.cc
+++ b/components/policy/core/common/policy_loader_win_unittest.cc
@@ -23,7 +23,6 @@
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
-#include "base/sys_byteorder.h"
 #include "base/task/sequenced_task_runner.h"
 #include "base/values.h"
 #include "base/win/registry.h"
diff --git a/components/policy/core/common/registry_dict.cc b/components/policy/core/common/registry_dict.cc
index ea4e052c6a669..845e73d35eab5 100644
--- a/components/policy/core/common/registry_dict.cc
+++ b/components/policy/core/common/registry_dict.cc
@@ -10,10 +10,10 @@
 
 #include "base/json/json_reader.h"
 #include "base/logging.h"
+#include "base/numerics/byte_conversions.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
-#include "base/sys_byteorder.h"
 #include "base/values.h"
 #include "build/build_config.h"
 #include "components/policy/core/common/schema.h"
diff --git a/components/segmentation_platform/internal/database/ukm_url_table.cc b/components/segmentation_platform/internal/database/ukm_url_table.cc
index c557cb616bda5..4bf099f66b294 100644
--- a/components/segmentation_platform/internal/database/ukm_url_table.cc
+++ b/components/segmentation_platform/internal/database/ukm_url_table.cc
@@ -9,7 +9,6 @@
 #include "base/containers/span.h"
 #include "base/hash/md5.h"
 #include "base/logging.h"
-#include "base/sys_byteorder.h"
 #include "components/database_utils/url_converter.h"
 #include "sql/database.h"
 #include "sql/statement.h"
diff --git a/content/child/font_warmup_win_unittest.cc b/content/child/font_warmup_win_unittest.cc
index 051af55e65a2c..ad0e2101dc785 100644
--- a/content/child/font_warmup_win_unittest.cc
+++ b/content/child/font_warmup_win_unittest.cc
@@ -17,7 +17,6 @@
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/path_service.h"
-#include "base/sys_byteorder.h"
 #include "base/test/task_environment.h"
 
 #include "content/child/dwrite_font_proxy/dwrite_font_proxy_win.h"
diff --git a/crypto/encryptor.cc b/crypto/encryptor.cc
index 0677147f9aad8..ade03b28ffb96 100644
--- a/crypto/encryptor.cc
+++ b/crypto/encryptor.cc
@@ -9,7 +9,6 @@
 
 #include "base/logging.h"
 #include "base/strings/string_util.h"
-#include "base/sys_byteorder.h"
 #include "crypto/openssl_util.h"
 #include "crypto/symmetric_key.h"
 #include "third_party/boringssl/src/include/openssl/aes.h"
diff --git a/device/fido/cable/v2_handshake.cc b/device/fido/cable/v2_handshake.cc
index 7776e711d7761..755702e6ed237 100644
--- a/device/fido/cable/v2_handshake.cc
+++ b/device/fido/cable/v2_handshake.cc
@@ -12,12 +12,12 @@
 #include <type_traits>
 
 #include "base/base64url.h"
+#include "base/numerics/byte_conversions.h"
 #include "base/numerics/safe_conversions.h"
 #include "base/numerics/safe_math.h"
 #include "base/ranges/algorithm.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
-#include "base/sys_byteorder.h"
 #include "components/cbor/reader.h"
 #include "components/cbor/values.h"
 #include "components/cbor/writer.h"
diff --git a/media/base/android/media_drm_bridge.cc b/media/base/android/media_drm_bridge.cc
index 9c2df9b65d7a5..bddc2f62b0d68 100644
--- a/media/base/android/media_drm_bridge.cc
+++ b/media/base/android/media_drm_bridge.cc
@@ -23,7 +23,6 @@
 #include "base/ranges/algorithm.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
-#include "base/sys_byteorder.h"
 #include "base/system/sys_info.h"
 #include "base/task/single_thread_task_runner.h"
 #include "media/base/android/android_util.h"
diff --git a/media/cast/encoding/audio_encoder.cc b/media/cast/encoding/audio_encoder.cc
index b22b66d686aae..d6151862f607e 100644
--- a/media/cast/encoding/audio_encoder.cc
+++ b/media/cast/encoding/audio_encoder.cc
@@ -19,7 +19,6 @@
 #include "base/logging.h"
 #include "base/memory/raw_ptr.h"
 #include "base/numerics/byte_conversions.h"
-#include "base/sys_byteorder.h"
 #include "base/time/time.h"
 #include "base/trace_event/trace_event.h"
 #include "build/build_config.h"
diff --git a/media/cast/test/receiver/audio_decoder.cc b/media/cast/test/receiver/audio_decoder.cc
index d4694f723e498..b82bcdef06c09 100644
--- a/media/cast/test/receiver/audio_decoder.cc
+++ b/media/cast/test/receiver/audio_decoder.cc
@@ -17,7 +17,6 @@
 #include "base/memory/raw_ptr.h"
 #include "base/numerics/byte_conversions.h"
 #include "base/numerics/safe_conversions.h"
-#include "base/sys_byteorder.h"
 #include "build/build_config.h"
 #include "media/cast/common/encoded_frame.h"
 #include "third_party/opus/src/include/opus.h"
diff --git a/media/cast/test/receiver/audio_decoder_unittest.cc b/media/cast/test/receiver/audio_decoder_unittest.cc
index 4a71c00095de3..782a2db15d1e5 100644
--- a/media/cast/test/receiver/audio_decoder_unittest.cc
+++ b/media/cast/test/receiver/audio_decoder_unittest.cc
@@ -11,9 +11,9 @@
 
 #include "base/functional/bind.h"
 #include "base/functional/callback_helpers.h"
+#include "base/numerics/byte_conversions.h"
 #include "base/synchronization/condition_variable.h"
 #include "base/synchronization/lock.h"
-#include "base/sys_byteorder.h"
 #include "base/time/time.h"
 #include "build/build_config.h"
 #include "media/cast/cast_config.h"
diff --git a/media/filters/audio_decoder_unittest.cc b/media/filters/audio_decoder_unittest.cc
index e43f408b79e5c..6a77f64374dab 100644
--- a/media/filters/audio_decoder_unittest.cc
+++ b/media/filters/audio_decoder_unittest.cc
@@ -16,7 +16,6 @@
 #include "base/hash/md5.h"
 #include "base/run_loop.h"
 #include "base/strings/stringprintf.h"
-#include "base/sys_byteorder.h"
 #include "base/test/task_environment.h"
 #include "base/threading/platform_thread.h"
 #include "base/time/time.h"
diff --git a/media/filters/mac/audio_toolbox_audio_decoder.cc b/media/filters/mac/audio_toolbox_audio_decoder.cc
index 5427bc5d289a6..293446f567397 100644
--- a/media/filters/mac/audio_toolbox_audio_decoder.cc
+++ b/media/filters/mac/audio_toolbox_audio_decoder.cc
@@ -12,7 +12,6 @@
 #include "base/logging.h"
 #include "base/memory/raw_ptr.h"
 #include "base/ranges/algorithm.h"
-#include "base/sys_byteorder.h"
 #include "base/task/bind_post_task.h"
 #include "media/base/audio_buffer.h"
 #include "media/base/audio_codecs.h"
diff --git a/media/filters/vp9_parser.cc b/media/filters/vp9_parser.cc
index 432628d49fea6..3e51d76c2790a 100644
--- a/media/filters/vp9_parser.cc
+++ b/media/filters/vp9_parser.cc
@@ -18,8 +18,8 @@
 #include "base/functional/bind.h"
 #include "base/functional/callback_helpers.h"
 #include "base/logging.h"
+#include "base/numerics/byte_conversions.h"
 #include "base/numerics/safe_conversions.h"
-#include "base/sys_byteorder.h"
 #include "media/filters/vp9_compressed_header_parser.h"
 #include "media/filters/vp9_uncompressed_header_parser.h"
 
diff --git a/media/filters/vpx_video_decoder.cc b/media/filters/vpx_video_decoder.cc
index 682da52bf6fc1..869464ef0c2f4 100644
--- a/media/filters/vpx_video_decoder.cc
+++ b/media/filters/vpx_video_decoder.cc
@@ -19,7 +19,6 @@
 #include "base/logging.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/numerics/byte_conversions.h"
-#include "base/sys_byteorder.h"
 #include "base/task/bind_post_task.h"
 #include "base/trace_event/trace_event.h"
 #include "media/base/decoder_buffer.h"
diff --git a/media/video/gpu_memory_buffer_video_frame_pool.cc b/media/video/gpu_memory_buffer_video_frame_pool.cc
index 0442784dd6535..9d5b9426013e5 100644
--- a/media/video/gpu_memory_buffer_video_frame_pool.cc
+++ b/media/video/gpu_memory_buffer_video_frame_pool.cc
@@ -26,7 +26,6 @@
 #include "base/metrics/histogram_macros.h"
 #include "base/ranges/algorithm.h"
 #include "base/strings/stringprintf.h"
-#include "base/sys_byteorder.h"
 #include "base/task/sequenced_task_runner.h"
 #include "base/time/default_tick_clock.h"
 #include "base/time/time.h"
diff --git a/pdf/pdfium/pdfium_font_linux.cc b/pdf/pdfium/pdfium_font_linux.cc
index 48743a7a01fac..37b33a9bb0600 100644
--- a/pdf/pdfium/pdfium_font_linux.cc
+++ b/pdf/pdfium/pdfium_font_linux.cc
@@ -27,7 +27,6 @@
 #include "base/posix/eintr_wrapper.h"
 #include "base/sequence_checker.h"
 #include "base/strings/string_util.h"
-#include "base/sys_byteorder.h"
 #include "components/services/font/public/cpp/font_loader.h"
 #include "pdf/pdfium/pdfium_engine.h"
 #include "third_party/blink/public/platform/web_font_description.h"
diff --git a/remoting/protocol/stun_tcp_packet_processor.cc b/remoting/protocol/stun_tcp_packet_processor.cc
index 1e861994aab66..b88b1ede0e0d9 100644
--- a/remoting/protocol/stun_tcp_packet_processor.cc
+++ b/remoting/protocol/stun_tcp_packet_processor.cc
@@ -8,7 +8,6 @@
 #include "base/no_destructor.h"
 #include "base/notreached.h"
 #include "base/numerics/byte_conversions.h"
-#include "base/sys_byteorder.h"
 #include "net/base/io_buffer.h"
 #include "third_party/webrtc/media/base/rtp_utils.h"
 #include "third_party/webrtc/rtc_base/time_utils.h"
diff --git a/services/network/mdns_responder.cc b/services/network/mdns_responder.cc
index ebd733589d311..6feb2081c7e97 100644
--- a/services/network/mdns_responder.cc
+++ b/services/network/mdns_responder.cc
@@ -12,7 +12,6 @@
 #include <string>
 #include <utility>
 
-#include "base/big_endian.h"
 #include "base/functional/bind.h"
 #include "base/logging.h"
 #include "base/memory/raw_ptr.h"
@@ -20,7 +19,6 @@
 #include "base/numerics/safe_conversions.h"
 #include "base/rand_util.h"
 #include "base/strings/stringprintf.h"
-#include "base/sys_byteorder.h"
 #include "base/time/default_tick_clock.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
diff --git a/services/network/p2p/socket_udp_unittest.cc b/services/network/p2p/socket_udp_unittest.cc
index c36a8fbbe8b0d..b03ce075b1f9d 100644
--- a/services/network/p2p/socket_udp_unittest.cc
+++ b/services/network/p2p/socket_udp_unittest.cc
@@ -16,7 +16,6 @@
 #include "base/memory/raw_ptr.h"
 #include "base/notreached.h"
 #include "base/run_loop.h"
-#include "base/sys_byteorder.h"
 #include "base/test/task_environment.h"
 #include "base/time/time.h"
 #include "base/unguessable_token.h"
diff --git a/services/network/public/cpp/server/web_socket.cc b/services/network/public/cpp/server/web_socket.cc
index 3caa4dc891ccf..40c43c67566dc 100644
--- a/services/network/public/cpp/server/web_socket.cc
+++ b/services/network/public/cpp/server/web_socket.cc
@@ -11,7 +11,6 @@
 #include "base/hash/sha1.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/stringprintf.h"
-#include "base/sys_byteorder.h"
 #include "net/websockets/websocket_deflate_parameters.h"
 #include "net/websockets/websocket_extension.h"
 #include "net/websockets/websocket_handshake_constants.h"
diff --git a/third_party/blink/common/origin_trials/trial_token.cc b/third_party/blink/common/origin_trials/trial_token.cc
index 5fbe7ba84bbee..be1fa6c754ebb 100644
--- a/third_party/blink/common/origin_trials/trial_token.cc
+++ b/third_party/blink/common/origin_trials/trial_token.cc
@@ -8,10 +8,10 @@
 #include <optional>
 
 #include "base/base64.h"
-#include "base/big_endian.h"
 #include "base/json/json_reader.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
+#include "base/numerics/byte_conversions.h"
 #include "base/strings/strcat.h"
 #include "base/strings/string_piece.h"
 #include "base/time/time.h"
diff --git a/third_party/blink/public/common/privacy_budget/identifiable_token_builder.h b/third_party/blink/public/common/privacy_budget/identifiable_token_builder.h
index 4e6135c559b9d..d028526ba6fab 100644
--- a/third_party/blink/public/common/privacy_budget/identifiable_token_builder.h
+++ b/third_party/blink/public/common/privacy_budget/identifiable_token_builder.h
@@ -9,7 +9,6 @@
 
 #include "base/containers/span.h"
 #include "base/strings/string_piece.h"
-#include "base/sys_byteorder.h"
 #include "base/template_util.h"
 #include "third_party/blink/public/common/common_export.h"
 #include "third_party/blink/public/common/privacy_budget/identifiability_internal_templates.h"
diff --git a/third_party/blink/renderer/bindings/core/v8/serialization/serialized_script_value.cc b/third_party/blink/renderer/bindings/core/v8/serialization/serialized_script_value.cc
index e836c7092b6cc..0111a34ce9833 100644
--- a/third_party/blink/renderer/bindings/core/v8/serialization/serialized_script_value.cc
+++ b/third_party/blink/renderer/bindings/core/v8/serialization/serialized_script_value.cc
@@ -37,7 +37,6 @@
 #include "base/numerics/checked_math.h"
 #include "base/numerics/safe_conversions.h"
 #include "base/ranges/algorithm.h"
-#include "base/sys_byteorder.h"
 #include "base/types/expected_macros.h"
 #include "third_party/blink/public/web/web_serialized_script_value_version.h"
 #include "third_party/blink/renderer/bindings/core/v8/idl_types.h"
diff --git a/third_party/blink/renderer/bindings/core/v8/serialization/v8_script_value_serializer.cc b/third_party/blink/renderer/bindings/core/v8/serialization/v8_script_value_serializer.cc
index 1c5e474eb12c2..a6cdd42c18221 100644
--- a/third_party/blink/renderer/bindings/core/v8/serialization/v8_script_value_serializer.cc
+++ b/third_party/blink/renderer/bindings/core/v8/serialization/v8_script_value_serializer.cc
@@ -6,7 +6,7 @@
 
 #include "base/auto_reset.h"
 #include "base/feature_list.h"
-#include "base/sys_byteorder.h"
+#include "base/numerics/byte_conversions.h"
 #include "third_party/blink/public/common/features.h"
 #include "third_party/blink/public/mojom/use_counter/metrics/web_feature.mojom-blink.h"
 #include "third_party/blink/public/platform/web_blob_info.h"
diff --git a/third_party/blink/renderer/core/html/canvas/image_data.cc b/third_party/blink/renderer/core/html/canvas/image_data.cc
index 6bfe3079d6b51..4522815ce9e86 100644
--- a/third_party/blink/renderer/core/html/canvas/image_data.cc
+++ b/third_party/blink/renderer/core/html/canvas/image_data.cc
@@ -28,7 +28,6 @@
 
 #include "third_party/blink/renderer/core/html/canvas/image_data.h"
 
-#include "base/sys_byteorder.h"
 #include "third_party/blink/renderer/bindings/core/v8/to_v8_traits.h"
 #include "third_party/blink/renderer/bindings/core/v8/v8_image_bitmap_options.h"
 #include "third_party/blink/renderer/bindings/core/v8/v8_union_float32array_uint16array_uint8clampedarray.h"
diff --git a/third_party/blink/renderer/modules/font_access/font_metadata.cc b/third_party/blink/renderer/modules/font_access/font_metadata.cc
index ea2f708249200..b870f6d7699bc 100644
--- a/third_party/blink/renderer/modules/font_access/font_metadata.cc
+++ b/third_party/blink/renderer/modules/font_access/font_metadata.cc
@@ -7,10 +7,8 @@
 #include <memory>
 #include <utility>
 
-#include "base/big_endian.h"
 #include "base/metrics/histogram_functions.h"
 #include "base/numerics/safe_conversions.h"
-#include "base/sys_byteorder.h"
 #include "build/build_config.h"
 #include "third_party/blink/renderer/bindings/core/v8/script_promise_resolver.h"
 #include "third_party/blink/renderer/core/fileapi/blob.h"
diff --git a/third_party/blink/renderer/platform/fonts/simple_font_data.cc b/third_party/blink/renderer/platform/fonts/simple_font_data.cc
index a1eba66d079ae..6b94dc56dfa7f 100644
--- a/third_party/blink/renderer/platform/fonts/simple_font_data.cc
+++ b/third_party/blink/renderer/platform/fonts/simple_font_data.cc
@@ -36,7 +36,7 @@
 #include <utility>
 
 #include "base/memory/ptr_util.h"
-#include "base/sys_byteorder.h"
+#include "base/numerics/byte_conversions.h"
 #include "build/build_config.h"
 #include "skia/ext/font_utils.h"
 #include "third_party/blink/renderer/platform/font_family_names.h"
diff --git a/third_party/blink/renderer/platform/graphics/color_correction_test_utils.cc b/third_party/blink/renderer/platform/graphics/color_correction_test_utils.cc
index c13a076b53e8f..8383dffd6f82f 100644
--- a/third_party/blink/renderer/platform/graphics/color_correction_test_utils.cc
+++ b/third_party/blink/renderer/platform/graphics/color_correction_test_utils.cc
@@ -6,7 +6,6 @@
 
 #include "base/containers/heap_array.h"
 #include "base/notreached.h"
-#include "base/sys_byteorder.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/skia/modules/skcms/skcms.h"
 
diff --git a/third_party/blink/renderer/platform/graphics/logging_canvas.cc b/third_party/blink/renderer/platform/graphics/logging_canvas.cc
index d5ebaecebf98d..23b3fcfd2f2a1 100644
--- a/third_party/blink/renderer/platform/graphics/logging_canvas.cc
+++ b/third_party/blink/renderer/platform/graphics/logging_canvas.cc
@@ -33,7 +33,6 @@
 #include <unicode/unistr.h>
 
 #include "base/logging.h"
-#include "base/sys_byteorder.h"
 #include "build/build_config.h"
 #include "third_party/blink/renderer/platform/graphics/skia/skia_utils.h"
 #include "third_party/blink/renderer/platform/image-encoders/image_encoder.h"
diff --git a/third_party/blink/renderer/platform/p2p/ipc_network_manager.cc b/third_party/blink/renderer/platform/p2p/ipc_network_manager.cc
index c6db51b0d5419..2ffbccded61a3 100644
--- a/third_party/blink/renderer/platform/p2p/ipc_network_manager.cc
+++ b/third_party/blink/renderer/platform/p2p/ipc_network_manager.cc
@@ -12,7 +12,6 @@
 #include "base/logging.h"
 #include "base/memory/weak_ptr.h"
 #include "base/metrics/histogram_macros.h"
-#include "base/sys_byteorder.h"
 #include "base/task/single_thread_task_runner.h"
 #include "components/webrtc/net_address_utils.h"
 #include "net/base/ip_address.h"
diff --git a/third_party/zlib/google/compression_utils.cc b/third_party/zlib/google/compression_utils.cc
index c2b17e4ced6f2..0ba31101489fd 100644
--- a/third_party/zlib/google/compression_utils.cc
+++ b/third_party/zlib/google/compression_utils.cc
@@ -6,7 +6,6 @@
 
 #include "base/check_op.h"
 #include "base/process/memory.h"
-#include "base/sys_byteorder.h"
 
 #include "third_party/zlib/google/compression_utils_portable.h"
 
diff --git a/ui/base/resource/data_pack.cc b/ui/base/resource/data_pack.cc
index 57b7f19a3b18f..f500fa3cbbcc2 100644
--- a/ui/base/resource/data_pack.cc
+++ b/ui/base/resource/data_pack.cc
@@ -22,8 +22,6 @@
 #include "base/memory/ref_counted_memory.h"
 #include "base/strings/string_piece.h"
 #include "base/synchronization/lock.h"
-#include "base/sys_byteorder.h"
-#include "build/build_config.h"
 #include "net/filter/gzip_header.h"
 #include "third_party/zlib/google/compression_utils.h"
 #include "ui/base/resource/resource_scale_factor.h"
@@ -378,12 +376,6 @@ base::StringPiece DataPack::GetStringPieceFromOffset(
 
 std::optional<base::StringPiece> DataPack::GetStringPiece(
     uint16_t resource_id) const {
-  // It won't be hard to make this endian-agnostic, but it's not worth
-  // bothering to do right now.
-#if !defined(ARCH_CPU_LITTLE_ENDIAN)
-#error "datapack assumes little endian"
-#endif
-
   const Entry* target = LookupEntryById(resource_id);
   if (!target)
     return std::nullopt;
@@ -455,9 +447,6 @@ void DataPack::CheckForDuplicateResources(
 bool DataPack::WritePack(const base::FilePath& path,
                          const std::map<uint16_t, base::StringPiece>& resources,
                          TextEncodingType text_encoding_type) {
-#if !defined(ARCH_CPU_LITTLE_ENDIAN)
-#error "datapack assumes little endian"
-#endif
   if (text_encoding_type != UTF8 && text_encoding_type != UTF16 &&
       text_encoding_type != BINARY) {
     LOG(ERROR) << "Invalid text encoding type, got " << text_encoding_type
diff --git a/ui/base/x/x11_cursor_loader_unittest.cc b/ui/base/x/x11_cursor_loader_unittest.cc
index fd445b86e7688..082f3e5eb0798 100644
--- a/ui/base/x/x11_cursor_loader_unittest.cc
+++ b/ui/base/x/x11_cursor_loader_unittest.cc
@@ -6,8 +6,9 @@
 
 #undef Bool
 
+#include "base/containers/span.h"
 #include "base/memory/ref_counted_memory.h"
-#include "base/sys_byteorder.h"
+#include "base/numerics/byte_conversions.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace ui {
diff --git a/ui/base/x/x11_pointer_grab.cc b/ui/base/x/x11_pointer_grab.cc
index 1b4e28e7db095..b64b320e1228a 100644
--- a/ui/base/x/x11_pointer_grab.cc
+++ b/ui/base/x/x11_pointer_grab.cc
@@ -8,7 +8,6 @@
 #include "base/check.h"
 #include "base/functional/bind.h"
 #include "base/no_destructor.h"
-#include "base/sys_byteorder.h"
 #include "ui/base/x/x11_util.h"
 #include "ui/events/devices/x11/device_data_manager_x11.h"
 #include "ui/gfx/x/connection.h"