diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 9801ed2..4a0137d 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -1,13 +1,13 @@
 # Setup file lists up
 set(YYCC_HEADER ${CMAKE_CURRENT_LIST_DIR})
 set(YYCC_SRC
+    ConsoleHelper.cpp
     DialogHelper.cpp
     EncodingHelper.cpp
     ExceptionHelper.cpp
     IOHelper.cpp
     ParserHelper.cpp
     StringHelper.cpp
-    TerminalHelper.cpp
 )
 
 # Create static library
diff --git a/src/TerminalHelper.cpp b/src/ConsoleHelper.cpp
similarity index 95%
rename from src/TerminalHelper.cpp
rename to src/ConsoleHelper.cpp
index 3b3a757..8741514 100644
--- a/src/TerminalHelper.cpp
+++ b/src/ConsoleHelper.cpp
@@ -1,4 +1,4 @@
-#include "TerminalHelper.hpp"
+#include "ConsoleHelper.hpp"
 #if YYCC_OS == YYCC_OS_WINDOWS
 
 #include "EncodingHelper.hpp"
@@ -11,7 +11,7 @@
 #include <fcntl.h>
 #include "WinImportSuffix.hpp"
 
-namespace YYCC::TerminalHelper {
+namespace YYCC::ConsoleHelper {
 
 	bool EnsureTerminalColor(FILE* fs) {
 		if (!_isatty(_fileno(fs))) return false;
diff --git a/src/TerminalHelper.hpp b/src/ConsoleHelper.hpp
similarity index 98%
rename from src/TerminalHelper.hpp
rename to src/ConsoleHelper.hpp
index 17f7608..5ca8964 100644
--- a/src/TerminalHelper.hpp
+++ b/src/ConsoleHelper.hpp
@@ -5,7 +5,7 @@
 #include <cstdio>
 #include <string>
 
-namespace YYCC::TerminalHelper {
+namespace YYCC::ConsoleHelper {
 	
 #define YYCC_TERMCOLHDR_BLACK "\033[30m"
 #define YYCC_TERMCOLHDR_RED "\033[31m"
diff --git a/src/ParserHelper.hpp b/src/ParserHelper.hpp
index 062679c..b23dba7 100644
--- a/src/ParserHelper.hpp
+++ b/src/ParserHelper.hpp
@@ -6,55 +6,45 @@
 #include <cinttypes>
 #include <type_traits>
 #include <stdexcept>
-#include <limits>
+#include <charconv>
+#include <array>
 
 namespace YYCC::ParserHelper {
 
-	template<class>
-	constexpr bool g_AlwaysFalse = false;
+	// Reference: https://zh.cppreference.com/w/cpp/utility/from_chars
 
 	template<typename _Ty, std::enable_if_t<std::is_floating_point_v<_Ty>, int> = 0>
 	bool TryParse(const std::string& strl, _Ty& num) {
-		try {
-			// float types
-			if constexpr (std::is_same_v<_Ty, float>) {
-				num = std::stof(strl, nullptr);
-			} else if constexpr (std::is_same_v<_Ty, double>) {
-				num = std::stod(strl, nullptr);
-			} else if constexpr (std::is_same_v<_Ty, long double>) {
-				num = std::stold(strl, nullptr);
-			} else {
-				static_assert(g_AlwaysFalse<_Ty>, "Invalid float type.");
-			}
-			return true;
-		} catch (const std::invalid_argument&) {
+		auto [ptr, ec] = std::from_chars(strl.c_str(), strl.c_str() + strl.size(), num, std::chars_format::general);
+		if (ec == std::errc()) {
+			// check whether the full string is matched
+			return ptr == strl.c_str() + strl.size();
+		} else if (ec == std::errc::invalid_argument) {
+			// given string is invalid
 			return false;
-		} catch (const std::out_of_range&) {
+		} else if (ec == std::errc::result_out_of_range) {
+			// given string is out of range
 			return false;
+		} else {
+			// unreachable
+			throw std::runtime_error("unreachable code.");
 		}
 	}
 	template<typename _Ty, std::enable_if_t<std::is_integral_v<_Ty> && !std::is_same_v<_Ty, bool>, int> = 0>
 	bool TryParse(const std::string& strl, _Ty& num, int base = 10) {
-		try {
-			// integer type
-			// decide integer type
-			using container_t = std::conditional_t<std::is_unsigned_v<_Ty>, unsigned long long, long long>;
-			// parse it from string according to whether integer type is signed.
-			container_t cache;
-			if constexpr (std::is_unsigned_v<_Ty>) {
-				cache = std::stoull(strl, nullptr, base);
-			} else {
-				cache = std::stoll(strl, nullptr, base);
-			}
-			// check its range
-			if (cache < std::numeric_limits<_Ty>::min() || cache > std::numeric_limits<_Ty>::max())
-				return false;
-			num = static_cast<_Ty>(cache);
-			return true;
-		} catch (const std::invalid_argument&) {
+		auto [ptr, ec] = std::from_chars(strl.c_str(), strl.c_str() + strl.size(), num, base);
+		if (ec == std::errc()) {
+			// check whether the full string is matched
+			return ptr == strl.c_str() + strl.size();
+		} else if (ec == std::errc::invalid_argument) {
+			// given string is invalid
 			return false;
-		} catch (const std::out_of_range&) {
+		} else if (ec == std::errc::result_out_of_range) {
+			// given string is out of range
 			return false;
+		} else {
+			// unreachable
+			throw std::runtime_error("unreachable code.");
 		}
 	}
 	template<typename _Ty, std::enable_if_t<std::is_same_v<_Ty, bool>, int> = 0>
@@ -72,12 +62,25 @@ namespace YYCC::ParserHelper {
 		return ret;
 	}
 
-	template<typename _Ty, std::enable_if_t<std::is_arithmetic_v<_Ty>, int> = 0>
+	// Reference: https://en.cppreference.com/w/cpp/utility/to_chars
+
+	template<typename _Ty, std::enable_if_t<std::is_arithmetic_v<_Ty> && !std::is_same_v<_Ty, bool>, int> = 0>
 	std::string ToString(_Ty num) {
-		return std::to_string(num);
+		std::array<char, 64> buffer;
+		auto [ptr, ec] = std::to_chars(buffer.data(), buffer.data() + buffer.size(), num);
+		if (ec == std::errc()) {
+			return std::string(buffer.data(), ptr - buffer.data());
+		} else if (ec == std::errc::value_too_large) {
+			// too short buffer
+			// this should not happend
+			throw std::out_of_range("ToString() buffer is not sufficient.");
+		} else {
+			// unreachable
+			throw std::runtime_error("unreachable code.");
+		}
 	}
-	template<>
-	std::string ToString<bool>(bool num) {
+	template<typename _Ty, std::enable_if_t<std::is_same_v<_Ty, bool>, int> = 0>
+	std::string ToString(_Ty num) {
 		if (num) return std::string("true");
 		else return std::string("false");
 	}
diff --git a/src/YYCCommonplace.hpp b/src/YYCCommonplace.hpp
index 21180fa..4b375f4 100644
--- a/src/YYCCommonplace.hpp
+++ b/src/YYCCommonplace.hpp
@@ -4,6 +4,6 @@
 
 #include "StringHelper.hpp"
 #include "EncodingHelper.hpp"
-#include "TerminalHelper.hpp"
+#include "ConsoleHelper.hpp"
 #include "DialogHelper.hpp"
 #include "ParserHelper.hpp"
diff --git a/testbench/main.cpp b/testbench/main.cpp
index aff8989..2996234 100644
--- a/testbench/main.cpp
+++ b/testbench/main.cpp
@@ -5,23 +5,44 @@ namespace Testbench {
 
 	static void Assert(bool condition, const char* description) {
 		if (condition) {
-			YYCC::TerminalHelper::FPrintf(stdout, YYCC_TERMCOL_LIGHT_GREEN("OK: %s\n"), description);
+			YYCC::ConsoleHelper::FPrintf(stdout, YYCC_TERMCOL_LIGHT_GREEN("OK: %s\n"), description);
 		} else {
-			YYCC::TerminalHelper::FPrintf(stdout, YYCC_TERMCOL_LIGHT_RED("Failed: %s\n"), description);
+			YYCC::ConsoleHelper::FPrintf(stdout, YYCC_TERMCOL_LIGHT_RED("Failed: %s\n"), description);
 			std::abort();
 		}
 	}
 
 	static void TerminalTestbench() {
-		YYCC::TerminalHelper::EnsureTerminalUTF8(stdout);
-		YYCC::TerminalHelper::FPuts("你好世界\n", stdout);
-		YYCC::TerminalHelper::EnsureTerminalColor(stdout);
-		YYCC::TerminalHelper::FPuts(YYCC_TERMCOL_LIGHT_CYAN("Colorful Terminal\n"), stdout);
+		// UTF8 Test
+		// Ref: https://stackoverflow.com/questions/478201/how-to-test-an-application-for-correct-encoding-e-g-utf-8
+		YYCC::ConsoleHelper::EnsureTerminalUTF8(stdout);
+		YYCC::ConsoleHelper::FPuts("UTF8 Test:\n", stdout);
+		static std::vector<const char*> c_TestStrings {
+			"\u30E6\u30FC\u30B6\u30FC\u5225\u30B5\u30A4\u30C8", // JAPAN
+			"\u7B80\u4F53\u4E2D\u6587", // CHINA
+			"\uD06C\uB85C\uC2A4 \uD50C\uB7AB\uD3FC\uC73C\uB85C", // KOREA
+			"\u05DE\u05D3\u05D5\u05E8\u05D9\u05DD \u05DE\u05D1\u05D5\u05E7\u05E9\u05D9\u05DD", // ISRAEL
+			"\u0623\u0641\u0636\u0644 \u0627\u0644\u0628\u062D\u0648\u062B", // EGYPT
+			"\u03A3\u1F72 \u03B3\u03BD\u03C9\u03C1\u03AF\u03B6\u03C9 \u1F00\u03C0\u1F78", // GREECE
+			"\u0414\u0435\u0441\u044F\u0442\u0443\u044E \u041C\u0435\u0436\u0434\u0443\u043D\u0430\u0440\u043E\u0434\u043D\u0443\u044E", // RUSSIA
+			"\u0E41\u0E1C\u0E48\u0E19\u0E14\u0E34\u0E19\u0E2E\u0E31\u0E48\u0E19\u0E40\u0E2A\u0E37\u0E48\u0E2D\u0E21\u0E42\u0E17\u0E23\u0E21\u0E41\u0E2A\u0E19\u0E2A\u0E31\u0E07\u0E40\u0E27\u0E0A", // THAILAND
+			"fran\u00E7ais langue \u00E9trang\u00E8re", // FRANCE
+			"ma\u00F1ana ol\u00E9", // SPAIN
+			"\u222E E\u22C5da = Q,  n \u2192 \u221E, \u2211 f(i) = \u220F g(i)", // MATHMATICS
+			//"\xF0\x9F\x8D\xA3 \xE2\x9C\x96 \xF0\x9F\x8D\xBA", // EMOJI
+		};
+		for (const auto* ptr : c_TestStrings) {
+			YYCC::ConsoleHelper::FPrintf(stdout, "\t%s\n", ptr);
+		}
+
+		// Color Test
+		YYCC::ConsoleHelper::EnsureTerminalColor(stdout);
+		YYCC::ConsoleHelper::FPuts(YYCC_TERMCOL_LIGHT_CYAN("Colorful Terminal\n"), stdout);
 	}
 
 	static void StringTestbench() {
-		auto test_printf = YYCC::StringHelper::Printf("%s == %s", "Hello World", "你好世界");
-		Assert(test_printf == "Hello World == 你好世界", "YYCC::StringHelper::Printf");
+		auto test_printf = YYCC::StringHelper::Printf("%s == %s", "Hello World", "Hello, world");
+		Assert(test_printf == "Hello World == Hello, world", "YYCC::StringHelper::Printf");
 			
 		auto test_lower = YYCC::StringHelper::Lower("LOWER");
 		Assert(test_lower == "lower", "YYCC::StringHelper::Lower");
@@ -130,20 +151,20 @@ namespace Testbench {
 		filters.Add("All Files (*.*)", {"*.*"});
 		params.SetDefaultFileTypeIndex(0u);
 		if (YYCC::DialogHelper::OpenFileDialog(params, ret)) {
-			YYCC::TerminalHelper::FPrintf(stdout, "Open File: %s\n", ret.c_str());
+			YYCC::ConsoleHelper::FPrintf(stdout, "Open File: %s\n", ret.c_str());
 		}
 		if (YYCC::DialogHelper::OpenMultipleFileDialog(params, rets)) {
-			YYCC::TerminalHelper::FPuts("Open Multiple Files:\n", stdout);
+			YYCC::ConsoleHelper::FPuts("Open Multiple Files:\n", stdout);
 			for (const auto& item : rets) {
-				YYCC::TerminalHelper::FPrintf(stdout, "\t%s\n", item.c_str());
+				YYCC::ConsoleHelper::FPrintf(stdout, "\t%s\n", item.c_str());
 			}
 		}
 		if (YYCC::DialogHelper::SaveFileDialog(params, ret)) {
-			YYCC::TerminalHelper::FPrintf(stdout, "Save File: %s\n", ret.c_str());
+			YYCC::ConsoleHelper::FPrintf(stdout, "Save File: %s\n", ret.c_str());
 		}
 		params.Clear();
 		if (YYCC::DialogHelper::OpenFolderDialog(params, ret)) {
-			YYCC::TerminalHelper::FPrintf(stdout, "Open Folder: %s\n", ret.c_str());
+			YYCC::ConsoleHelper::FPrintf(stdout, "Open Folder: %s\n", ret.c_str());
 		}
 	}