diff --git a/deps/zlib/CMakeLists.txt b/deps/zlib/CMakeLists.txt
index 471a3a46a09dd6..234eab8db41def 100644
--- a/deps/zlib/CMakeLists.txt
+++ b/deps/zlib/CMakeLists.txt
@@ -24,6 +24,7 @@ check_include_file(stddef.h    HAVE_STDDEF_H)
 option(ENABLE_SIMD_OPTIMIZATIONS "Enable all SIMD optimizations" OFF)
 option(ENABLE_SIMD_AVX512 "Enable SIMD AXV512 optimizations" OFF)
 option(USE_ZLIB_RABIN_KARP_HASH "Enable bitstream compatibility with canonical zlib" OFF)
+option(BUILD_UNITTESTS "Enable standalone unit tests build" OFF)
 
 if (USE_ZLIB_RABIN_KARP_HASH)
    add_definitions(-DUSE_ZLIB_RABIN_KARP_ROLLING_HASH)
@@ -244,6 +245,58 @@ set(CMAKE_CXX_STANDARD 14) # workaround for older compilers (e.g. g++ 5.4).
 add_executable(zlib_bench contrib/bench/zlib_bench.cc)
 target_link_libraries(zlib_bench zlib)
 
+#============================================================================
+# Unit Tests
+#============================================================================
+if (BUILD_UNITTESTS)
+    include (ExternalProject)
+    set_directory_properties(PROPERTIES EP_PREFIX ${CMAKE_BINARY_DIR}/third_party)
+    ExternalProject_add(
+        googletest
+        GIT_REPOSITORY https://github.com/google/googletest.git
+        GIT_TAG d1467f5813f4d363cfd11aba99c4e9fe47a85e99
+        UPDATE_COMMAND ""
+        INSTALL_COMMAND ""
+        LOG_DOWNLOAD ON
+        LOG_CONFIGURE ON
+        LOG_BUILD ON
+    )
+
+    # gtest includedir
+    ExternalProject_Get_Property(googletest source_dir)
+    set(GTEST_INCLUDE_DIRS
+        ${source_dir}/googletest/include
+        ${source_dir}/googletest/include/gtest
+    )
+
+    # gtest library
+    ExternalProject_Get_Property(googletest binary_dir)
+    set(GTEST_LIBRARY_PATH ${binary_dir}/lib/${CMAKE_FIND_LIBRARY_PREFIXES}gtest.a)
+    set(GTEST_LIBRARY gtest)
+    add_library(${GTEST_LIBRARY} UNKNOWN IMPORTED)
+    set_property(TARGET ${GTEST_LIBRARY} PROPERTY IMPORTED_LOCATION ${GTEST_LIBRARY_PATH})
+    add_dependencies(${GTEST_LIBRARY} googletest)
+
+    set(UTEST_SRC
+        ${CMAKE_CURRENT_SOURCE_DIR}/contrib/tests/infcover.cc
+        ${CMAKE_CURRENT_SOURCE_DIR}/contrib/tests/infcover.h
+        ${CMAKE_CURRENT_SOURCE_DIR}/contrib/tests/utils_unittest.cc
+        ${CMAKE_CURRENT_SOURCE_DIR}/contrib/tests/standalone_test_runner.cc
+        ${CMAKE_CURRENT_SOURCE_DIR}/google/compression_utils_portable.cc
+    )
+
+    add_compile_definitions(CMAKE_STANDALONE_UNITTESTS)
+
+    add_executable(zlib_unittests ${UTEST_SRC})
+    target_include_directories(zlib_unittests PUBLIC ${GTEST_INCLUDE_DIRS})
+    target_include_directories(zlib_unittests PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/google)
+
+    target_link_libraries(zlib_unittests ${GTEST_LIBRARY})
+    target_link_libraries(zlib_unittests zlib)
+    # Needed by gtest
+    target_link_libraries(zlib_unittests pthread)
+endif()
+
 #============================================================================
 # Minigzip tool
 #============================================================================
diff --git a/deps/zlib/README.chromium b/deps/zlib/README.chromium
index 663ee0521ed30c..1dfb99666423ea 100644
--- a/deps/zlib/README.chromium
+++ b/deps/zlib/README.chromium
@@ -5,7 +5,7 @@ Version: 1.2.13
 CPEPrefix: cpe:/a:zlib:zlib:1.2.13
 Security Critical: yes
 Shipped: yes
-License: Custom license
+License: Zlib
 License File: LICENSE
 License Android Compatible: yes
 
diff --git a/deps/zlib/contrib/optimizations/inflate.c b/deps/zlib/contrib/optimizations/inflate.c
index 6ed87160f5350d..2a8e0ef76db6ba 100644
--- a/deps/zlib/contrib/optimizations/inflate.c
+++ b/deps/zlib/contrib/optimizations/inflate.c
@@ -1488,8 +1488,9 @@ int ZEXPORT inflateCopy(z_streamp dest, z_streamp source) {
     if (copy == Z_NULL) return Z_MEM_ERROR;
     window = Z_NULL;
     if (state->window != Z_NULL) {
-        window = (unsigned char FAR *)
-                 ZALLOC(source, 1U << state->wbits, sizeof(unsigned char));
+        window = (unsigned char FAR *)ZALLOC(
+            source, (1U << state->wbits) + CHUNKCOPY_CHUNK_SIZE,
+            sizeof(unsigned char));
         if (window == Z_NULL) {
             ZFREE(source, copy);
             return Z_MEM_ERROR;
diff --git a/deps/zlib/contrib/optimizations/insert_string.h b/deps/zlib/contrib/optimizations/insert_string.h
index c6a296aef7390e..260b8268029a8c 100644
--- a/deps/zlib/contrib/optimizations/insert_string.h
+++ b/deps/zlib/contrib/optimizations/insert_string.h
@@ -16,64 +16,7 @@
 #endif
 #endif
 
-#include "cpu_features.h"
-
-// clang-format off
-#if defined(CRC32_SIMD_SSE42_PCLMUL)
-  #include <smmintrin.h>  /* Required to make MSVC bot build pass. */
-
-  #if defined(__clang__) || defined(__GNUC__)
-    #define TARGET_CPU_WITH_CRC __attribute__((target("sse4.2")))
-  #else
-    #define TARGET_CPU_WITH_CRC
-  #endif
-
-  /* CRC32C uint32_t */
-  #define _cpu_crc32c_hash_u32 _mm_crc32_u32
-
-#elif defined(CRC32_ARMV8_CRC32)
-  #if defined(__clang__)
-    #define __crc32cw __builtin_arm_crc32cw
-  #elif defined(__GNUC__)
-    #define __crc32cw __builtin_aarch64_crc32cw
-  #endif
-
-  #if defined(__aarch64__) && defined(__clang__)
-    #define TARGET_CPU_WITH_CRC __attribute__((target("crc")))
-  #elif defined(__aarch64__) && defined(__GNUC__)
-    #define TARGET_CPU_WITH_CRC __attribute__((target("+crc")))
-  #elif defined(__clang__) // !defined(__aarch64__)
-    #define TARGET_CPU_WITH_CRC __attribute__((target("armv8-a,crc")))
-  #endif  // defined(__aarch64__)
-
-  /* CRC32C uint32_t */
-  #define _cpu_crc32c_hash_u32 __crc32cw
-
-#endif
-// clang-format on
-
-#if defined(TARGET_CPU_WITH_CRC)
-
-TARGET_CPU_WITH_CRC
-local INLINE Pos insert_string_simd(deflate_state* const s, const Pos str) {
-  Pos ret;
-  unsigned val, h = 0;
-
-  zmemcpy(&val, &s->window[str], sizeof(val));
-
-  if (s->level >= 6)
-    val &= 0xFFFFFF;
-
-  /* Compute hash from the CRC32C of |val|. */
-  h = _cpu_crc32c_hash_u32(h, val);
-
-  ret = s->head[h & s->hash_mask];
-  s->head[h & s->hash_mask] = str;
-  s->prev[str & s->w_mask] = ret;
-  return ret;
-}
-
-#endif // TARGET_CPU_WITH_CRC
+#include <stdint.h>
 
 /**
  * Some applications need to match zlib DEFLATE output exactly [3]. Use the
@@ -107,10 +50,23 @@ local INLINE Pos insert_string_simd(deflate_state* const s, const Pos str) {
  *    characters and the first MIN_MATCH bytes of str are valid (except for
  *    the last MIN_MATCH-1 bytes of the input file).
  */
-local INLINE Pos insert_string_c(deflate_state* const s, const Pos str) {
+local INLINE Pos insert_string(deflate_state* const s, const Pos str) {
   Pos ret;
-
+/* insert_string dictionary insertion: ANZAC++ hasher
+ * significantly improves data compression speed.
+ *
+ * Note: the generated compressed output is a valid DEFLATE stream, but will
+ * differ from canonical zlib output.
+ */
+#if defined(USE_ZLIB_RABIN_KARP_ROLLING_HASH)
   UPDATE_HASH(s, s->ins_h, s->window[(str) + (MIN_MATCH - 1)]);
+#else
+  uint32_t value;
+  // Validated for little endian archs (i.e. x86, Arm). YMMV for big endian.
+  zmemcpy(&value, &s->window[str], sizeof(value));
+  s->ins_h = ((value * 66521 + 66521) >> 16) & s->hash_mask;
+#endif
+
 #ifdef FASTEST
   ret = s->head[s->ins_h];
 #else
@@ -121,25 +77,4 @@ local INLINE Pos insert_string_c(deflate_state* const s, const Pos str) {
   return ret;
 }
 
-local INLINE Pos insert_string(deflate_state* const s, const Pos str) {
-/* insert_string_simd string dictionary insertion: SIMD crc32c symbol hasher
- * significantly improves data compression speed.
- *
- * Note: the generated compressed output is a valid DEFLATE stream, but will
- * differ from canonical zlib output.
- */
-#if defined(USE_ZLIB_RABIN_KARP_ROLLING_HASH)
-/* So this build-time option can be used to disable the crc32c hash, and use
- * the Rabin-Karp hash instead.
- */ /* FALLTHROUGH Rabin-Karp */
-#elif defined(TARGET_CPU_WITH_CRC) && defined(CRC32_SIMD_SSE42_PCLMUL)
-  if (x86_cpu_enable_simd)
-    return insert_string_simd(s, str);
-#elif defined(TARGET_CPU_WITH_CRC) && defined(CRC32_ARMV8_CRC32)
-  if (arm_cpu_enable_crc32)
-    return insert_string_simd(s, str);
-#endif
-  return insert_string_c(s, str); /* Rabin-Karp */
-}
-
 #endif /* INSERT_STRING_H */
diff --git a/deps/zlib/contrib/tests/standalone_test_runner.cc b/deps/zlib/contrib/tests/standalone_test_runner.cc
new file mode 100644
index 00000000000000..1ec9c30bacba02
--- /dev/null
+++ b/deps/zlib/contrib/tests/standalone_test_runner.cc
@@ -0,0 +1,9 @@
+// Copyright 2023 The Chromium Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the Chromium source repository LICENSE file.
+#include <gtest/gtest.h>
+
+int main(int argc, char** argv) {
+  ::testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}
diff --git a/deps/zlib/contrib/tests/utils_unittest.cc b/deps/zlib/contrib/tests/utils_unittest.cc
index 7270d0af90855f..d06dbc9812ad92 100644
--- a/deps/zlib/contrib/tests/utils_unittest.cc
+++ b/deps/zlib/contrib/tests/utils_unittest.cc
@@ -7,12 +7,17 @@
 #include <cstddef>
 #include <vector>
 
-#include "base/files/file_path.h"
-#include "base/files/scoped_temp_dir.h"
 #include "compression_utils_portable.h"
 #include "gtest.h"
+
+#if !defined(CMAKE_STANDALONE_UNITTESTS)
+#include "base/files/file_path.h"
+#include "base/files/scoped_temp_dir.h"
+
 #include "third_party/zlib/contrib/minizip/unzip.h"
 #include "third_party/zlib/contrib/minizip/zip.h"
+#endif
+
 #include "zlib.h"
 
 void TestPayloads(size_t input_size, zlib_internal::WrapperType type) {
@@ -1020,6 +1025,9 @@ TEST(ZlibTest, DeflateZFixedCorruption) {
       0);
 }
 
+// TODO(gustavoa): make these tests run standalone.
+#ifndef CMAKE_STANDALONE_UNITTESTS
+
 TEST(ZlibTest, ZipFilenameCommentSize) {
   // Check that minizip rejects zip member filenames or comments longer than
   // the zip format can represent.
@@ -1138,3 +1146,5 @@ TEST(ZlibTest, ZipExtraFieldSize) {
   EXPECT_EQ(unzGoToNextFile(uzf), UNZ_END_OF_LIST_OF_FILE);
   EXPECT_EQ(unzClose(uzf), UNZ_OK);
 }
+
+#endif
diff --git a/deps/zlib/deflate.c b/deps/zlib/deflate.c
index 1fa55e5d010618..173ce596be582e 100644
--- a/deps/zlib/deflate.c
+++ b/deps/zlib/deflate.c
@@ -457,15 +457,9 @@ int ZEXPORT deflateInit2_(z_streamp strm, int level, int method,
     s->w_size = 1 << s->w_bits;
     s->w_mask = s->w_size - 1;
 
+    s->chromium_zlib_hash = 1;
+#if defined(USE_ZLIB_RABIN_KARP_ROLLING_HASH)
     s->chromium_zlib_hash = 0;
-#if !defined(USE_ZLIB_RABIN_KARP_ROLLING_HASH)
-  #if defined(TARGET_CPU_WITH_CRC) && defined(CRC32_SIMD_SSE42_PCLMUL)
-    if (x86_cpu_enable_simd)
-      s->chromium_zlib_hash = 1;
-  #elif defined(TARGET_CPU_WITH_CRC) && defined(CRC32_ARMV8_CRC32)
-    if (arm_cpu_enable_crc32)
-      s->chromium_zlib_hash = 1;
-  #endif
 #endif
 
     s->hash_bits = memLevel + 7;
diff --git a/deps/zlib/google/DEPS b/deps/zlib/google/DEPS
index 03f2cb950b9517..7ec5343ee23953 100644
--- a/deps/zlib/google/DEPS
+++ b/deps/zlib/google/DEPS
@@ -2,5 +2,6 @@ include_rules = [
   '+base',
   '+build',
   '+testing',
-  "+third_party/zlib/zlib.h",
+  '+third_party/icu/source/i18n/unicode',
+  '+third_party/zlib/zlib.h',
 ]
diff --git a/deps/zlib/google/zip_internal.cc b/deps/zlib/google/zip_internal.cc
index 9b20b421e24765..b9976d63ee301b 100644
--- a/deps/zlib/google/zip_internal.cc
+++ b/deps/zlib/google/zip_internal.cc
@@ -260,12 +260,13 @@ zip_fileinfo TimeToZipFileInfo(const base::Time& file_time) {
     // It assumes that dates below 1980 are in the double digit format.
     // Hence the fail safe option is to leave the date unset. Some programs
     // might show the unset date as 1980-0-0 which is invalid.
-    zip_info.tmz_date.tm_year = file_time_parts.year;
-    zip_info.tmz_date.tm_mon = file_time_parts.month - 1;
-    zip_info.tmz_date.tm_mday = file_time_parts.day_of_month;
-    zip_info.tmz_date.tm_hour = file_time_parts.hour;
-    zip_info.tmz_date.tm_min = file_time_parts.minute;
-    zip_info.tmz_date.tm_sec = file_time_parts.second;
+    zip_info.tmz_date = {
+        .tm_sec = static_cast<uInt>(file_time_parts.second),
+        .tm_min = static_cast<uInt>(file_time_parts.minute),
+        .tm_hour = static_cast<uInt>(file_time_parts.hour),
+        .tm_mday = static_cast<uInt>(file_time_parts.day_of_month),
+        .tm_mon = static_cast<uInt>(file_time_parts.month - 1),
+        .tm_year = static_cast<uInt>(file_time_parts.year)};
   }
 
   return zip_info;
diff --git a/deps/zlib/google/zip_reader.cc b/deps/zlib/google/zip_reader.cc
index 9b1030a029c8a4..34a815e5f52e9f 100644
--- a/deps/zlib/google/zip_reader.cc
+++ b/deps/zlib/google/zip_reader.cc
@@ -246,14 +246,14 @@ bool ZipReader::OpenEntry() {
 
   // Construct the last modified time. The timezone info is not present in ZIP
   // archives, so we construct the time as UTC.
-  base::Time::Exploded exploded_time = {};
-  exploded_time.year = info.tmu_date.tm_year;
-  exploded_time.month = info.tmu_date.tm_mon + 1;  // 0-based vs 1-based
-  exploded_time.day_of_month = info.tmu_date.tm_mday;
-  exploded_time.hour = info.tmu_date.tm_hour;
-  exploded_time.minute = info.tmu_date.tm_min;
-  exploded_time.second = info.tmu_date.tm_sec;
-  exploded_time.millisecond = 0;
+  const base::Time::Exploded exploded_time = {
+      .year = static_cast<int>(info.tmu_date.tm_year),
+      .month =
+          static_cast<int>(info.tmu_date.tm_mon + 1),  // 0-based vs 1-based
+      .day_of_month = static_cast<int>(info.tmu_date.tm_mday),
+      .hour = static_cast<int>(info.tmu_date.tm_hour),
+      .minute = static_cast<int>(info.tmu_date.tm_min),
+      .second = static_cast<int>(info.tmu_date.tm_sec)};
 
   if (!base::Time::FromUTCExploded(exploded_time, &entry_.last_modified))
     entry_.last_modified = base::Time::UnixEpoch();
diff --git a/deps/zlib/google/zip_reader_unittest.cc b/deps/zlib/google/zip_reader_unittest.cc
index b9175045d07268..6086c97c49b622 100644
--- a/deps/zlib/google/zip_reader_unittest.cc
+++ b/deps/zlib/google/zip_reader_unittest.cc
@@ -19,6 +19,7 @@
 #include "base/files/scoped_temp_dir.h"
 #include "base/functional/bind.h"
 #include "base/hash/md5.h"
+#include "base/i18n/time_formatting.h"
 #include "base/path_service.h"
 #include "base/run_loop.h"
 #include "base/strings/string_piece.h"
@@ -31,6 +32,7 @@
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/platform_test.h"
+#include "third_party/icu/source/i18n/unicode/timezone.h"
 #include "third_party/zlib/google/zip_internal.h"
 
 using ::testing::_;
@@ -288,18 +290,10 @@ TEST_F(ZipReaderTest, RegularFile) {
 
   EXPECT_EQ(target_path, entry->path);
   EXPECT_EQ(13527, entry->original_size);
-
-  // The expected time stamp: 2009-05-29 06:22:20
-  base::Time::Exploded exploded = {};  // Zero-clear.
-  entry->last_modified.UTCExplode(&exploded);
-  EXPECT_EQ(2009, exploded.year);
-  EXPECT_EQ(5, exploded.month);
-  EXPECT_EQ(29, exploded.day_of_month);
-  EXPECT_EQ(6, exploded.hour);
-  EXPECT_EQ(22, exploded.minute);
-  EXPECT_EQ(20, exploded.second);
-  EXPECT_EQ(0, exploded.millisecond);
-
+  EXPECT_EQ("2009-05-29 06:22:20.000",
+            base::UnlocalizedTimeFormatWithPattern(entry->last_modified,
+                                                   "y-MM-dd HH:mm:ss.SSS",
+                                                   icu::TimeZone::getGMT()));
   EXPECT_FALSE(entry->is_unsafe);
   EXPECT_FALSE(entry->is_directory);
 }
@@ -396,18 +390,10 @@ TEST_F(ZipReaderTest, Directory) {
   EXPECT_EQ(target_path, entry->path);
   // The directory size should be zero.
   EXPECT_EQ(0, entry->original_size);
-
-  // The expected time stamp: 2009-05-31 15:49:52
-  base::Time::Exploded exploded = {};  // Zero-clear.
-  entry->last_modified.UTCExplode(&exploded);
-  EXPECT_EQ(2009, exploded.year);
-  EXPECT_EQ(5, exploded.month);
-  EXPECT_EQ(31, exploded.day_of_month);
-  EXPECT_EQ(15, exploded.hour);
-  EXPECT_EQ(49, exploded.minute);
-  EXPECT_EQ(52, exploded.second);
-  EXPECT_EQ(0, exploded.millisecond);
-
+  EXPECT_EQ("2009-05-31 15:49:52.000",
+            base::UnlocalizedTimeFormatWithPattern(entry->last_modified,
+                                                   "y-MM-dd HH:mm:ss.SSS",
+                                                   icu::TimeZone::getGMT()));
   EXPECT_FALSE(entry->is_unsafe);
   EXPECT_TRUE(entry->is_directory);
 }
diff --git a/doc/contributing/maintaining/maintaining-dependencies.md b/doc/contributing/maintaining/maintaining-dependencies.md
index 4cec1dce2c0a3e..eb0e5960a7c5b8 100644
--- a/doc/contributing/maintaining/maintaining-dependencies.md
+++ b/doc/contributing/maintaining/maintaining-dependencies.md
@@ -30,7 +30,7 @@ This a list of all the dependencies:
 * [uv][]
 * [uvwasi 0.0.19][]
 * [V8][]
-* [zlib 1.2.13.1-motley-f5fd0ad][]
+* [zlib 1.2.13.1-motley-fef5869][]
 
 Any code which meets one or more of these conditions should
 be managed as a dependency:
@@ -304,7 +304,7 @@ See [maintaining-web-assembly][] for more informations.
 high-performance JavaScript and WebAssembly engine, written in C++.
 See [maintaining-V8][] for more informations.
 
-### zlib 1.2.13.1-motley-f5fd0ad
+### zlib 1.2.13.1-motley-fef5869
 
 The [zlib](https://chromium.googlesource.com/chromium/src/+/refs/heads/main/third_party/zlib)
 dependency lossless data-compression library,
@@ -341,4 +341,4 @@ performance improvements not currently available in standard zlib.
 [uv]: #uv
 [uvwasi 0.0.19]: #uvwasi-0019
 [v8]: #v8
-[zlib 1.2.13.1-motley-f5fd0ad]: #zlib-12131-motley-f5fd0ad
+[zlib 1.2.13.1-motley-fef5869]: #zlib-12131-motley-fef5869