diff --git a/sdk/core/azure-core/CHANGELOG.md b/sdk/core/azure-core/CHANGELOG.md
index 21b434168..074ee032e 100644
--- a/sdk/core/azure-core/CHANGELOG.md
+++ b/sdk/core/azure-core/CHANGELOG.md
@@ -2,6 +2,9 @@
 
 ## 1.0.0-beta.5 (Unreleased)
 
+### Breaking Changes
+
+- Make `ToLower` and `LocaleInvariantCaseInsensitiveEqual` internal by moving them from `Azure::Core::Strings` to `Azure::Core::Internal::Strings`.
 
 ## 1.0.0-beta.4 (2021-01-13)
 
diff --git a/sdk/core/azure-core/CMakeLists.txt b/sdk/core/azure-core/CMakeLists.txt
index 53d83716d..fdad1a44a 100644
--- a/sdk/core/azure-core/CMakeLists.txt
+++ b/sdk/core/azure-core/CMakeLists.txt
@@ -63,6 +63,7 @@ set(
     inc/azure/core/http/transport.hpp
     inc/azure/core/internal/contract.hpp
     inc/azure/core/internal/log.hpp
+    inc/azure/core/internal/strings.hpp
     inc/azure/core/logging/logging.hpp
     inc/azure/core/base64.hpp
     inc/azure/core/context.hpp
@@ -74,7 +75,6 @@ set(
     inc/azure/core/operation_status.hpp
     inc/azure/core/platform.hpp
     inc/azure/core/response.hpp
-    inc/azure/core/strings.hpp
     inc/azure/core/uuid.hpp
     inc/azure/core/version.hpp
     inc/azure/core.hpp
diff --git a/sdk/core/azure-core/inc/azure/core.hpp b/sdk/core/azure-core/inc/azure/core.hpp
index 0b1930c78..748440b05 100644
--- a/sdk/core/azure-core/inc/azure/core.hpp
+++ b/sdk/core/azure-core/inc/azure/core.hpp
@@ -16,7 +16,6 @@
 #include "azure/core/datetime.hpp"
 #include "azure/core/nullable.hpp"
 #include "azure/core/response.hpp"
-#include "azure/core/strings.hpp"
 #include "azure/core/uuid.hpp"
 #include "azure/core/version.hpp"
 
diff --git a/sdk/core/azure-core/inc/azure/core/strings.hpp b/sdk/core/azure-core/inc/azure/core/internal/strings.hpp
similarity index 67%
rename from sdk/core/azure-core/inc/azure/core/strings.hpp
rename to sdk/core/azure-core/inc/azure/core/internal/strings.hpp
index a4df0e195..0e121adcb 100644
--- a/sdk/core/azure-core/inc/azure/core/strings.hpp
+++ b/sdk/core/azure-core/inc/azure/core/internal/strings.hpp
@@ -2,17 +2,17 @@
 // SPDX-License-Identifier: MIT
 
 /**
- * @brief Public utility functions for strings.
+ * @brief Internal utility functions for strings.
  *
  */
 #pragma once
 
 #include <string>
 
-namespace Azure { namespace Core { namespace Strings {
+namespace Azure { namespace Core { namespace Internal { namespace Strings {
 
   bool LocaleInvariantCaseInsensitiveEqual(const std::string& lhs, const std::string& rhs) noexcept;
   std::string const ToLower(const std::string& src) noexcept;
   unsigned char ToLower(const unsigned char src) noexcept;
 
-}}} // namespace Azure::Core::Strings
+}}}} // namespace Azure::Core::Internal::Strings
diff --git a/sdk/core/azure-core/inc/azure/core/operation_status.hpp b/sdk/core/azure-core/inc/azure/core/operation_status.hpp
index 342836d69..f30ca3842 100644
--- a/sdk/core/azure-core/inc/azure/core/operation_status.hpp
+++ b/sdk/core/azure-core/inc/azure/core/operation_status.hpp
@@ -12,7 +12,7 @@
 #include <string>
 #include <utility> // for std::move
 
-#include "azure/core/strings.hpp"
+#include "azure/core/internal/strings.hpp"
 
 namespace Azure { namespace Core {
 
@@ -51,7 +51,7 @@ namespace Azure { namespace Core {
      */
     bool operator==(const OperationStatus& other) const noexcept
     {
-      return Strings::LocaleInvariantCaseInsensitiveEqual(m_value, other.m_value);
+      return Internal::Strings::LocaleInvariantCaseInsensitiveEqual(m_value, other.m_value);
     }
 
     /**
diff --git a/sdk/core/azure-core/src/http/raw_response.cpp b/sdk/core/azure-core/src/http/raw_response.cpp
index add21062b..6ab0e6d09 100644
--- a/sdk/core/azure-core/src/http/raw_response.cpp
+++ b/sdk/core/azure-core/src/http/raw_response.cpp
@@ -2,7 +2,7 @@
 // SPDX-License-Identifier: MIT
 
 #include "azure/core/http/http.hpp"
-#include "azure/core/strings.hpp"
+#include "azure/core/internal/strings.hpp"
 
 #include <cctype>
 #include <map>
@@ -32,7 +32,7 @@ void RawResponse::AddHeader(uint8_t const* const first, uint8_t const* const las
   }
 
   // Always toLower() headers
-  auto headerName = Azure::Core::Strings::ToLower(std::string(start, end));
+  auto headerName = Azure::Core::Internal::Strings::ToLower(std::string(start, end));
   start = end + 1; // start value
   while (start < last && (*start == ' ' || *start == '\t'))
   {
diff --git a/sdk/core/azure-core/src/http/request.cpp b/sdk/core/azure-core/src/http/request.cpp
index f317c8535..0e17bbccb 100644
--- a/sdk/core/azure-core/src/http/request.cpp
+++ b/sdk/core/azure-core/src/http/request.cpp
@@ -2,7 +2,7 @@
 // SPDX-License-Identifier: MIT
 
 #include "azure/core/http/http.hpp"
-#include "azure/core/strings.hpp"
+#include "azure/core/internal/strings.hpp"
 
 #include <map>
 #include <string>
@@ -24,7 +24,7 @@ static std::map<std::string, std::string> MergeMaps(
 
 void Request::AddHeader(std::string const& name, std::string const& value)
 {
-  auto headerNameLowerCase = Azure::Core::Strings::ToLower(name);
+  auto headerNameLowerCase = Azure::Core::Internal::Strings::ToLower(name);
   return this->m_retryModeEnabled
       ? Details::InsertHeaderWithValidation(this->m_retryHeaders, headerNameLowerCase, value)
       : Details::InsertHeaderWithValidation(this->m_headers, headerNameLowerCase, value);
diff --git a/sdk/core/azure-core/src/http/url.cpp b/sdk/core/azure-core/src/http/url.cpp
index 967ff50af..8672f2f80 100644
--- a/sdk/core/azure-core/src/http/url.cpp
+++ b/sdk/core/azure-core/src/http/url.cpp
@@ -2,7 +2,7 @@
 // SPDX-License-Identifier: MIT
 
 #include "azure/core/http/http.hpp"
-#include "azure/core/strings.hpp"
+#include "azure/core/internal/strings.hpp"
 
 #include <algorithm>
 #include <cctype>
@@ -21,7 +21,8 @@ Url::Url(const std::string& url)
   if (schemeIter != std::string::npos)
   {
     std::transform(url.begin(), url.begin() + schemeIter, std::back_inserter(m_scheme), [](char c) {
-      return static_cast<char>(Azure::Core::Strings::ToLower(static_cast<unsigned char>(c)));
+      return static_cast<char>(
+          Azure::Core::Internal::Strings::ToLower(static_cast<unsigned char>(c)));
     });
 
     pos = url.begin() + schemeIter + schemeEnd.length();
diff --git a/sdk/core/azure-core/src/strings.cpp b/sdk/core/azure-core/src/strings.cpp
index cac9021ad..6e0e01c81 100644
--- a/sdk/core/azure-core/src/strings.cpp
+++ b/sdk/core/azure-core/src/strings.cpp
@@ -1,7 +1,7 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // SPDX-License-Identifier: MIT
 
-#include "azure/core/strings.hpp"
+#include "azure/core/internal/strings.hpp"
 
 #include <algorithm>
 
@@ -67,7 +67,7 @@ const unsigned char c_LocaleInvariantLowercaseTable[256] = {
 };
 } // unnamed namespace
 
-namespace Azure { namespace Core { namespace Strings {
+namespace Azure { namespace Core { namespace Internal { namespace Strings {
 
   unsigned char ToLower(const unsigned char symbol) noexcept
   {
@@ -97,4 +97,4 @@ namespace Azure { namespace Core { namespace Strings {
         });
   }
 
-}}} // namespace Azure::Core::Strings
+}}}} // namespace Azure::Core::Internal::Strings
diff --git a/sdk/core/azure-core/test/ut/simplified_header.cpp b/sdk/core/azure-core/test/ut/simplified_header.cpp
index 4900aa567..f3e70f921 100644
--- a/sdk/core/azure-core/test/ut/simplified_header.cpp
+++ b/sdk/core/azure-core/test/ut/simplified_header.cpp
@@ -20,7 +20,6 @@ TEST(Logging, simplifiedHeader)
   EXPECT_NO_THROW(Azure::Core::Nullable<int> n);
   EXPECT_NO_THROW(Azure::Core::Http::RawResponse r(
       1, 1, Azure::Core::Http::HttpStatusCode::Accepted, "phrase"));
-  EXPECT_NO_THROW(Azure::Core::Strings::ToLower("A"));
   EXPECT_NO_THROW(Azure::Core::Uuid::CreateUuid());
   EXPECT_NO_THROW(Azure::Core::Details::Version::VersionString());
 
diff --git a/sdk/core/azure-core/test/ut/string.cpp b/sdk/core/azure-core/test/ut/string.cpp
index d15f44fe2..2744adf1d 100644
--- a/sdk/core/azure-core/test/ut/string.cpp
+++ b/sdk/core/azure-core/test/ut/string.cpp
@@ -1,13 +1,13 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // SPDX-License-Identifier: MIT
 
-#include <azure/core/strings.hpp>
+#include <azure/core/internal/strings.hpp>
 #include <gtest/gtest.h>
 #include <string>
 
 TEST(String, invariantCompare)
 {
-  using Azure::Core::Strings::LocaleInvariantCaseInsensitiveEqual;
+  using Azure::Core::Internal::Strings::LocaleInvariantCaseInsensitiveEqual;
   EXPECT_TRUE(LocaleInvariantCaseInsensitiveEqual("", ""));
   EXPECT_TRUE(LocaleInvariantCaseInsensitiveEqual("a", "a"));
   EXPECT_TRUE(LocaleInvariantCaseInsensitiveEqual("A", "a"));
@@ -22,7 +22,7 @@ TEST(String, invariantCompare)
 
 TEST(String, toLower)
 {
-  using Azure::Core::Strings::ToLower;
+  using Azure::Core::Internal::Strings::ToLower;
   EXPECT_TRUE(ToLower("") == "");
   EXPECT_TRUE(ToLower("a") == "a");
   EXPECT_TRUE(ToLower("A") == "a");
diff --git a/sdk/storage/azure-storage-blobs/inc/azure/storage/blobs/protocol/blob_rest_client.hpp b/sdk/storage/azure-storage-blobs/inc/azure/storage/blobs/protocol/blob_rest_client.hpp
index f2d061ea1..7b464912b 100644
--- a/sdk/storage/azure-storage-blobs/inc/azure/storage/blobs/protocol/blob_rest_client.hpp
+++ b/sdk/storage/azure-storage-blobs/inc/azure/storage/blobs/protocol/blob_rest_client.hpp
@@ -18,7 +18,6 @@
 #include <azure/core/http/pipeline.hpp>
 #include <azure/core/nullable.hpp>
 #include <azure/core/response.hpp>
-#include <azure/core/strings.hpp>
 #include <azure/storage/common/crypt.hpp>
 #include <azure/storage/common/storage_common.hpp>
 #include <azure/storage/common/storage_exception.hpp>
diff --git a/sdk/storage/azure-storage-common/inc/azure/storage/common/storage_common.hpp b/sdk/storage/azure-storage-common/inc/azure/storage/common/storage_common.hpp
index 45a6b94ce..5fef87a7c 100644
--- a/sdk/storage/azure-storage-common/inc/azure/storage/common/storage_common.hpp
+++ b/sdk/storage/azure-storage-common/inc/azure/storage/common/storage_common.hpp
@@ -9,7 +9,7 @@
 #include <string>
 #include <vector>
 
-#include <azure/core/strings.hpp>
+#include <azure/core/internal/strings.hpp>
 
 namespace Azure { namespace Storage {
 
@@ -57,7 +57,7 @@ namespace Azure { namespace Storage {
       {
         return std::lexicographical_compare(
             lhs.begin(), lhs.end(), rhs.begin(), rhs.end(), [](char c1, char c2) {
-              return Core::Strings::ToLower(c1) < Core::Strings::ToLower(c2);
+              return Core::Internal::Strings::ToLower(c1) < Core::Internal::Strings::ToLower(c2);
             });
       }
     };
diff --git a/sdk/storage/azure-storage-common/src/shared_key_policy.cpp b/sdk/storage/azure-storage-common/src/shared_key_policy.cpp
index 018607fd2..defc8f4ad 100644
--- a/sdk/storage/azure-storage-common/src/shared_key_policy.cpp
+++ b/sdk/storage/azure-storage-common/src/shared_key_policy.cpp
@@ -7,7 +7,7 @@
 #include <cctype>
 
 #include <azure/core/http/http.hpp>
-#include <azure/core/strings.hpp>
+#include <azure/core/internal/strings.hpp>
 
 #include "azure/storage/common/crypt.hpp"
 
@@ -32,7 +32,7 @@ namespace Azure { namespace Storage { namespace Details {
           "If-Unmodified-Since",
           "Range"})
     {
-      auto ite = headers.find(Azure::Core::Strings::ToLower(headerName));
+      auto ite = headers.find(Azure::Core::Internal::Strings::ToLower(headerName));
       if (ite != headers.end())
       {
         if (headerName == "Content-Length" && ite->second == "0")
@@ -54,7 +54,7 @@ namespace Azure { namespace Storage { namespace Details {
          ite != headers.end() && ite->first.substr(0, prefix.length()) == prefix;
          ++ite)
     {
-      std::string key = Azure::Core::Strings::ToLower(ite->first);
+      std::string key = Azure::Core::Internal::Strings::ToLower(ite->first);
       ordered_kv.emplace_back(std::make_pair(std::move(key), ite->second));
     }
     std::sort(ordered_kv.begin(), ordered_kv.end());
@@ -68,7 +68,7 @@ namespace Azure { namespace Storage { namespace Details {
     string_to_sign += "/" + m_credential->AccountName + "/" + request.GetUrl().GetPath() + "\n";
     for (const auto& query : request.GetUrl().GetQueryParameters())
     {
-      std::string key = Azure::Core::Strings::ToLower(query.first);
+      std::string key = Azure::Core::Internal::Strings::ToLower(query.first);
       ordered_kv.emplace_back(std::make_pair(
           Azure::Core::Http::Url::Decode(key), Azure::Core::Http::Url::Decode(query.second)));
     }
diff --git a/sdk/storage/azure-storage-common/test/test_base.cpp b/sdk/storage/azure-storage-common/test/test_base.cpp
index 6e8ab9858..7555be901 100644
--- a/sdk/storage/azure-storage-common/test/test_base.cpp
+++ b/sdk/storage/azure-storage-common/test/test_base.cpp
@@ -20,8 +20,8 @@
 #include <string>
 
 #include <azure/core/http/http.hpp>
+#include <azure/core/internal/strings.hpp>
 #include <azure/core/platform.hpp>
-#include <azure/core/strings.hpp>
 
 namespace Azure { namespace Storage { namespace Test {
 
@@ -166,7 +166,7 @@ namespace Azure { namespace Storage { namespace Test {
 
   std::string LowercaseRandomString(size_t size)
   {
-    return Azure::Core::Strings::ToLower(RandomString(size));
+    return Azure::Core::Internal::Strings::ToLower(RandomString(size));
   }
 
   Storage::Metadata RandomMetadata(size_t size)