diff --git a/sherpa-onnx/csrc/offline-tts.cc b/sherpa-onnx/csrc/offline-tts.cc
index ec2c69523..d858b71b1 100644
--- a/sherpa-onnx/csrc/offline-tts.cc
+++ b/sherpa-onnx/csrc/offline-tts.cc
@@ -96,7 +96,27 @@ OfflineTts::~OfflineTts() = default;
 GeneratedAudio OfflineTts::Generate(
     const std::string &text, int64_t sid /*=0*/, float speed /*= 1.0*/,
     GeneratedAudioCallback callback /*= nullptr*/) const {
+#if !defined(_WIN32)
   return impl_->Generate(text, sid, speed, std::move(callback));
+#else
+  if (IsUtf8(text)) {
+    return impl_->Generate(text, sid, speed, std::move(callback));
+  } else if (IsGB2312(text)) {
+    auto utf8_text = Gb2312ToUtf8(text);
+    static bool printed = false;
+    if (!printed) {
+      SHERPA_ONNX_LOGE(
+          "Detected GB2312 encoded string! Converting it to UTF8.");
+      printed = true;
+    }
+    return impl_->Generate(utf8_text, sid, speed, std::move(callback));
+  } else {
+    SHERPA_ONNX_LOGE(
+        "Non UTF8 encoded string is received. You would not get expected "
+        "results!");
+    return impl_->Generate(text, sid, speed, std::move(callback));
+  }
+#endif
 }
 
 int32_t OfflineTts::SampleRate() const { return impl_->SampleRate(); }
diff --git a/sherpa-onnx/csrc/text-utils.cc b/sherpa-onnx/csrc/text-utils.cc
index 7259ed7c4..d0a64a8ce 100644
--- a/sherpa-onnx/csrc/text-utils.cc
+++ b/sherpa-onnx/csrc/text-utils.cc
@@ -16,6 +16,10 @@
 #include <utility>
 #include <vector>
 
+#if defined(_WIN32)
+#include <Windows.h>
+#endif
+
 #include "sherpa-onnx/csrc/macros.h"
 
 // This file is copied/modified from
@@ -502,4 +506,123 @@ std::string RemoveInvalidUtf8Sequences(const std::string &text,
   return ans;
 }
 
+bool IsUtf8(const std::string &text) {
+  int32_t n = static_cast<int32_t>(text.size());
+  int32_t i = 0;
+  const uint8_t *p = reinterpret_cast<const uint8_t *>(text.data());
+  while (i < n) {
+    if (p[i] <= 0x7f) {
+      i += 1;
+      continue;
+    }
+
+    if (InRange(p[i], 0xc2, 0xdf) && i + 1 < n &&
+        InRange(p[i + 1], 0x80, 0xbf)) {
+      i += 2;
+      continue;
+    }
+
+    if (p[i] == 0xe0 && i + 2 < n && InRange(p[i + 1], 0xa0, 0xbf) &&
+        InRange(p[i + 2], 0x80, 0xbf)) {
+      i += 3;
+      continue;
+    }
+
+    if (InRange(p[i], 0xe1, 0xec) && i + 2 < n &&
+        InRange(p[i + 1], 0x80, 0xbf) && InRange(p[i + 2], 0x80, 0xbf)) {
+      i += 3;
+      continue;
+    }
+
+    if (p[i] == 0xed && i + 2 < n && InRange(p[i + 1], 0x80, 0x9f) &&
+        InRange(p[i + 2], 0x80, 0xbf)) {
+      i += 3;
+      continue;
+    }
+
+    if (InRange(p[i], 0xee, 0xef) && i + 2 < n &&
+        InRange(p[i + 1], 0x80, 0xbf) && InRange(p[i + 2], 0x80, 0xbf)) {
+      i += 3;
+      continue;
+    }
+
+    if (p[i] == 0xf0 && i + 3 < n && InRange(p[i + 1], 0x90, 0xbf) &&
+        InRange(p[i + 2], 0x80, 0xbf) && InRange(p[i + 3], 0x80, 0xbf)) {
+      i += 4;
+      continue;
+    }
+
+    if (InRange(p[i], 0xf1, 0xf3) && i + 3 < n &&
+        InRange(p[i + 1], 0x80, 0xbf) && InRange(p[i + 2], 0x80, 0xbf) &&
+        InRange(p[i + 3], 0x80, 0xbf)) {
+      i += 4;
+      continue;
+    }
+
+    if (p[i] == 0xf4 && i + 3 < n && InRange(p[i + 1], 0x80, 0x8f) &&
+        InRange(p[i + 2], 0x80, 0xbf) && InRange(p[i + 3], 0x80, 0xbf)) {
+      i += 4;
+      continue;
+    }
+
+    return false;
+  }
+
+  return true;
+}
+
+bool IsGB2312(const std::string &text) {
+  int32_t n = static_cast<int32_t>(text.size());
+  int32_t i = 0;
+  const uint8_t *p = reinterpret_cast<const uint8_t *>(text.data());
+  while (i < n) {
+    if (p[i] <= 0x7f) {
+      i += 1;
+      continue;
+    }
+
+    if (InRange(p[i], 0xa1, 0xf7) && i + 1 < n &&
+        InRange(p[i + 1], 0xa1, 0xfe)) {
+      i += 2;
+      continue;
+    }
+
+    return false;
+  }
+
+  return true;
+}
+
+#if defined(_WIN32)
+std::string Gb2312ToUtf8(const std::string &text) {
+  // https://learn.microsoft.com/en-us/windows/win32/api/stringapiset/nf-stringapiset-multibytetowidechar
+  // 936 is from
+  // https://learn.microsoft.com/en-us/windows/win32/intl/code-page-identifiers
+  // GB2312 -> 936
+  int32_t num_wchars =
+      MultiByteToWideChar(936, 0, text.c_str(), text.size(), nullptr, 0);
+  SHERPA_ONNX_LOGE("num of wchars: %d", num_wchars);
+  if (num_wchars == 0) {
+    return {};
+  }
+
+  std::wstring wstr;
+  wstr.resize(num_wchars);
+  MultiByteToWideChar(936, 0, text.c_str(), text.size(), wstr.data(),
+                      num_wchars);
+  // https://learn.microsoft.com/en-us/windows/win32/api/stringapiset/nf-stringapiset-widechartomultibyte
+  int32_t num_chars = WideCharToMultiByte(CP_UTF8, 0, wstr.c_str(), -1, nullptr,
+                                          0, nullptr, nullptr);
+  if (num_chars == 0) {
+    return {};
+  }
+
+  std::string ans(num_chars, 0);
+  WideCharToMultiByte(CP_UTF8, 0, wstr.c_str(), -1, ans.data(), num_chars,
+                      nullptr, nullptr);
+
+  return ans;
+}
+#endif
+
 }  // namespace sherpa_onnx
diff --git a/sherpa-onnx/csrc/text-utils.h b/sherpa-onnx/csrc/text-utils.h
index a27137060..f0ecdb8e6 100644
--- a/sherpa-onnx/csrc/text-utils.h
+++ b/sherpa-onnx/csrc/text-utils.h
@@ -127,6 +127,18 @@ void ToLowerCase(std::string *in_out);
 std::string RemoveInvalidUtf8Sequences(const std::string &text,
                                        bool show_debug_msg = false);
 
+// Return true if text contains valid utf8 sequence.
+// Return false otherwise
+bool IsUtf8(const std::string &text);
+
+// Return true if text contains valid gb2312 encoded sequence
+// Return false otherwise
+bool IsGB2312(const std::string &text);
+
+#if defined(_WIN32)
+std::string Gb2312ToUtf8(const std::string &text);
+#endif
+
 }  // namespace sherpa_onnx
 
 #endif  // SHERPA_ONNX_CSRC_TEXT_UTILS_H_