diff --git a/autotest/Utf/Utf.cpp b/autotest/Utf/Utf.cpp
new file mode 100644
index 000000000..1ed1b30e4
--- /dev/null
+++ b/autotest/Utf/Utf.cpp
@@ -0,0 +1,87 @@
+#include <Core/Core.h>
+
+using namespace Upp;
+
+CONSOLE_APP_MAIN
+{
+	StdLogSetup(LOG_COUT|LOG_FILE);
+
+	for(dword code = 0; code <= 0x10ffff; code++) {
+		if(code < 0xee00 || code > 0xeeff) {
+			String s = ToUtf8(&code, 1);
+			Vector<dword> t = ToUtf32(s);
+			ASSERT(t[0] == code);
+			ASSERT(Utf32Len(s) == 1);
+			
+			WString ws = ToUtf16(&code, 1);
+			t = ToUtf32(ws);
+			ASSERT(t[0] == code);
+			ASSERT(Utf32Len(ws) == 1);
+			
+			ws = ToUtf16(s);
+			t = ToUtf32(ws);
+			ASSERT(t[0] == code);
+			ASSERT(Utf32Len(ws) == 1);
+			
+			s = ToUtf8(ws);
+			t = ToUtf32(s);
+			ASSERT(t[0] == code);
+			ASSERT(Utf32Len(ws) == 1);
+		}
+	}
+	
+	LOG("Single code test passed");
+	
+	SeedRandom(0);
+	for(int i = 0; i < 10000; i++) {
+		int n = Random(1000);
+		Vector<dword> text;
+		while(text.GetCount() < n) {
+			int code = Random(0x110000);
+			if(!(code >= 0xee00 && code < 0xeeff || code >= 0xD800 && code < 0xe000))
+				text.Add(code);
+		}
+
+		String s = ToUtf8(text);
+		Vector<dword> t = ToUtf32(s);
+		ASSERT(t == text);
+		ASSERT(Utf32Len(s) == n);
+		
+		WString ws = ToUtf16(text);
+		t = ToUtf32(ws);
+		if(t != text) {
+			DUMP(text);
+			DUMP(t);
+			DUMP(ws);
+		}
+		ASSERT(t == text);
+		ASSERT(Utf32Len(ws) == n);
+		
+		ws = ToUtf16(s);
+		t = ToUtf32(ws);
+		ASSERT(t == text);
+		ASSERT(Utf32Len(ws) == n);
+		
+		s = ToUtf8(ws);
+		t = ToUtf32(s);
+		ASSERT(t == text);
+		ASSERT(Utf32Len(ws) == n);
+	}
+
+	LOG("Text test passed");
+
+	SeedRandom(0);
+	for(int i = 0; i < 30000; i++) {
+		int n = Random(1000);
+		String text;
+		while(text.GetCount() < n)
+			text.Cat(Random(256));
+		
+		ASSERT(ToUtf8(ToUtf32(text)) == text);
+		ASSERT(ToUtf8(ToUtf16(text)) == text);
+	}
+
+	LOG("Error escape test passed");
+
+	LOG("========== OK");
+}
diff --git a/autotest/Utf/Utf.upp b/autotest/Utf/Utf.upp
new file mode 100644
index 000000000..c9f3fc00c
--- /dev/null
+++ b/autotest/Utf/Utf.upp
@@ -0,0 +1,9 @@
+uses
+	Core;
+
+file
+	Utf.cpp;
+
+mainconfig
+	"" = "";
+