diff --git a/egs/ljspeech/TTS/vits/export-onnx.py b/egs/ljspeech/TTS/vits/export-onnx.py
new file mode 100755
index 000000000..154de4bf4
--- /dev/null
+++ b/egs/ljspeech/TTS/vits/export-onnx.py
@@ -0,0 +1,261 @@
+#!/usr/bin/env python3
+#
+# Copyright      2023 Xiaomi Corporation     (Author: Zengwei Yao)
+#
+# See ../../../../LICENSE for clarification regarding multiple authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""
+This script exports a VITS model from PyTorch to ONNX.
+
+Export the model to ONNX:
+./vits/export-onnx.py \
+  --epoch 1000 \
+  --exp-dir vits/exp \
+  --tokens data/tokens.txt
+
+It will generate two files inside vits/exp:
+  - vits-epoch-1000.onnx
+  - vits-epoch-1000.int8.onnx (quantizated model)
+
+See ./test_onnx.py for how to use the exported ONNX models.
+"""
+
+import argparse
+import logging
+from pathlib import Path
+from typing import Dict, Tuple
+
+import onnx
+import torch
+import torch.nn as nn
+from onnxruntime.quantization import QuantType, quantize_dynamic
+from tokenizer import Tokenizer
+from train import get_model, get_params
+
+from icefall.checkpoint import load_checkpoint
+
+
+def get_parser():
+    parser = argparse.ArgumentParser(
+        formatter_class=argparse.ArgumentDefaultsHelpFormatter
+    )
+
+    parser.add_argument(
+        "--epoch",
+        type=int,
+        default=1000,
+        help="""It specifies the checkpoint to use for decoding.
+        Note: Epoch counts from 1.
+        """,
+    )
+
+    parser.add_argument(
+        "--exp-dir",
+        type=str,
+        default="vits/exp",
+        help="The experiment dir",
+    )
+
+    parser.add_argument(
+        "--tokens",
+        type=str,
+        default="data/tokens.txt",
+        help="""Path to vocabulary.""",
+    )
+
+    return parser
+
+
+def add_meta_data(filename: str, meta_data: Dict[str, str]):
+    """Add meta data to an ONNX model. It is changed in-place.
+
+    Args:
+      filename:
+        Filename of the ONNX model to be changed.
+      meta_data:
+        Key-value pairs.
+    """
+    model = onnx.load(filename)
+    for key, value in meta_data.items():
+        meta = model.metadata_props.add()
+        meta.key = key
+        meta.value = value
+
+    onnx.save(model, filename)
+
+
+class OnnxModel(nn.Module):
+    """A wrapper for VITS generator."""
+
+    def __init__(self, model: nn.Module):
+        """
+        Args:
+          model:
+            A VITS generator.
+          frame_shift:
+            The frame shift in samples.
+        """
+        super().__init__()
+        self.model = model
+
+    def forward(
+        self,
+        tokens: torch.Tensor,
+        tokens_lens: torch.Tensor,
+        noise_scale: float = 0.667,
+        noise_scale_dur: float = 0.8,
+        alpha: float = 1.0,
+    ) -> Tuple[torch.Tensor, torch.Tensor]:
+        """Please see the help information of VITS.inference_batch
+
+        Args:
+          tokens:
+            Input text token indexes (1, T_text)
+          tokens_lens:
+            Number of tokens of shape (1,)
+          noise_scale (float):
+            Noise scale parameter for flow.
+          noise_scale_dur (float):
+            Noise scale parameter for duration predictor.
+          alpha (float):
+            Alpha parameter to control the speed of generated speech.
+
+        Returns:
+          Return a tuple containing:
+            - audio, generated wavform tensor, (B, T_wav)
+        """
+        audio, _, _ = self.model.inference(
+            text=tokens,
+            text_lengths=tokens_lens,
+            noise_scale=noise_scale,
+            noise_scale_dur=noise_scale_dur,
+            alpha=alpha,
+        )
+        return audio
+
+
+def export_model_onnx(
+    model: nn.Module,
+    model_filename: str,
+    opset_version: int = 11,
+) -> None:
+    """Export the given generator model to ONNX format.
+    The exported model has one input:
+
+        - tokens, a tensor of shape (1, T_text); dtype is torch.int64
+
+    and it has one output:
+
+        - audio, a tensor of shape (1, T'); dtype is torch.float32
+
+    Args:
+      model:
+        The VITS generator.
+      model_filename:
+        The filename to save the exported ONNX model.
+      opset_version:
+        The opset version to use.
+    """
+    tokens = torch.randint(low=0, high=79, size=(1, 13), dtype=torch.int64)
+    tokens_lens = torch.tensor([tokens.shape[1]], dtype=torch.int64)
+    noise_scale = torch.tensor([1], dtype=torch.float32)
+    noise_scale_dur = torch.tensor([1], dtype=torch.float32)
+    alpha = torch.tensor([1], dtype=torch.float32)
+
+    torch.onnx.export(
+        model,
+        (tokens, tokens_lens, noise_scale, noise_scale_dur, alpha),
+        model_filename,
+        verbose=False,
+        opset_version=opset_version,
+        input_names=["tokens", "tokens_lens", "noise_scale", "noise_scale_dur", "alpha"],
+        output_names=["audio"],
+        dynamic_axes={
+            "tokens": {0: "N", 1: "T"},
+            "tokens_lens": {0: "N"},
+            "audio": {0: "N", 1: "T"},
+        },
+    )
+
+    meta_data = {
+        "model_type": "VITS",
+        "version": "1",
+        "model_author": "k2-fsa",
+        "comment": "VITS generator",
+    }
+    logging.info(f"meta_data: {meta_data}")
+
+    add_meta_data(filename=model_filename, meta_data=meta_data)
+
+
+@torch.no_grad()
+def main():
+    args = get_parser().parse_args()
+    args.exp_dir = Path(args.exp_dir)
+
+    params = get_params()
+    params.update(vars(args))
+
+    tokenizer = Tokenizer(params.tokens)
+    params.blank_id = tokenizer.blank_id
+    params.oov_id = tokenizer.oov_id
+    params.vocab_size = tokenizer.vocab_size
+
+    logging.info(params)
+
+    logging.info("About to create model")
+    model = get_model(params)
+
+    load_checkpoint(f"{params.exp_dir}/epoch-{params.epoch}.pt", model)
+
+    model = model.generator
+    model.to("cpu")
+    model.eval()
+
+    model = OnnxModel(model=model)
+
+    num_param = sum([p.numel() for p in model.parameters()])
+    logging.info(f"generator parameters: {num_param}")
+
+    suffix = f"epoch-{params.epoch}"
+
+    opset_version = 13
+
+    logging.info("Exporting encoder")
+    model_filename = params.exp_dir / f"vits-{suffix}.onnx"
+    export_model_onnx(
+        model,
+        model_filename,
+        opset_version=opset_version,
+    )
+    logging.info(f"Exported generator to {model_filename}")
+
+    # Generate int8 quantization models
+    # See https://onnxruntime.ai/docs/performance/model-optimizations/quantization.html#data-type-selection
+
+    logging.info("Generate int8 quantization models")
+
+    model_filename_int8 = params.exp_dir / f"vits-{suffix}.int8.onnx"
+    quantize_dynamic(
+        model_input=model_filename,
+        model_output=model_filename_int8,
+        weight_type=QuantType.QUInt8,
+    )
+
+
+if __name__ == "__main__":
+    formatter = "%(asctime)s %(levelname)s [%(filename)s:%(lineno)d] %(message)s"
+    logging.basicConfig(format=formatter, level=logging.INFO)
+    main()
diff --git a/egs/ljspeech/TTS/vits/generator.py b/egs/ljspeech/TTS/vits/generator.py
index 664d8064f..efb0e254c 100644
--- a/egs/ljspeech/TTS/vits/generator.py
+++ b/egs/ljspeech/TTS/vits/generator.py
@@ -403,6 +403,7 @@ class VITSGenerator(torch.nn.Module):
         """
         # encoder
         x, m_p, logs_p, x_mask = self.text_encoder(text, text_lengths)
+        x_mask = x_mask.to(x.dtype)
         g = None
         if self.spks is not None:
             # (B, global_channels, 1)
@@ -480,6 +481,7 @@ class VITSGenerator(torch.nn.Module):
                 dur = torch.ceil(w)
             y_lengths = torch.clamp_min(torch.sum(dur, [1, 2]), 1).long()
             y_mask = (~make_pad_mask(y_lengths)).unsqueeze(1).to(text.device)
+            y_mask = y_mask.to(x.dtype)
             attn_mask = torch.unsqueeze(x_mask, 2) * torch.unsqueeze(y_mask, -1)
             attn = self._generate_path(dur, attn_mask)
 
diff --git a/egs/ljspeech/TTS/vits/test_onnx.py b/egs/ljspeech/TTS/vits/test_onnx.py
new file mode 100755
index 000000000..8acca7c02
--- /dev/null
+++ b/egs/ljspeech/TTS/vits/test_onnx.py
@@ -0,0 +1,123 @@
+#!/usr/bin/env python3
+#
+# Copyright      2023 Xiaomi Corporation     (Author: Zengwei Yao)
+#
+# See ../../../../LICENSE for clarification regarding multiple authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""
+This script is used to test the exported onnx model by vits/export-onnx.py
+
+Use the onnx model to generate a wav:
+./vits/test_onnx.py \
+  --model-filename vits/exp/vits-epoch-1000.onnx \
+  --tokens data/tokens.txt
+"""
+
+
+import argparse
+import logging
+import onnxruntime as ort
+import torch
+import torchaudio
+
+from tokenizer import Tokenizer
+
+
+def get_parser():
+    parser = argparse.ArgumentParser(
+        formatter_class=argparse.ArgumentDefaultsHelpFormatter
+    )
+
+    parser.add_argument(
+        "--model-filename",
+        type=str,
+        required=True,
+        help="Path to the onnx model.",
+    )
+
+    parser.add_argument(
+        "--tokens",
+        type=str,
+        default="data/tokens.txt",
+        help="""Path to vocabulary.""",
+    )
+
+    return parser
+
+
+class OnnxModel:
+    def __init__(self, model_filename: str):
+        session_opts = ort.SessionOptions()
+        session_opts.inter_op_num_threads = 1
+        session_opts.intra_op_num_threads = 4
+
+        self.session_opts = session_opts
+
+        self.model = ort.InferenceSession(
+            model_filename,
+            sess_options=self.session_opts,
+            providers=["CPUExecutionProvider"],
+        )
+        logging.info(f"{self.model.get_modelmeta().custom_metadata_map}")
+
+    def __call__(self, tokens: torch.Tensor, tokens_lens: torch.Tensor) -> torch.Tensor:
+        """
+        Args:
+          tokens:
+            A 1-D tensor of shape (1, T)
+        Returns:
+            A tensor of shape (1, T')
+        """
+        noise_scale = torch.tensor([0.667], dtype=torch.float32)
+        noise_scale_dur = torch.tensor([0.8], dtype=torch.float32)
+        alpha = torch.tensor([1.0], dtype=torch.float32)
+
+        out = self.model.run(
+            [
+                self.model.get_outputs()[0].name,
+            ],
+            {
+                self.model.get_inputs()[0].name: tokens.numpy(),
+                self.model.get_inputs()[1].name: tokens_lens.numpy(),
+                self.model.get_inputs()[2].name: noise_scale.numpy(),
+                self.model.get_inputs()[3].name: noise_scale_dur.numpy(),
+                self.model.get_inputs()[4].name: alpha.numpy(),
+            },
+        )[0]
+        return torch.from_numpy(out)
+
+
+def main():
+    args = get_parser().parse_args()
+
+    tokenizer = Tokenizer(args.tokens)
+
+    logging.info("About to create onnx model")
+    model = OnnxModel(args.model_filename)
+
+    text = "I went there to see the land, the people and how their system works, end quote."
+    tokens = tokenizer.texts_to_token_ids([text])
+    tokens = torch.tensor(tokens)  # (1, T)
+    tokens_lens = torch.tensor([tokens.shape[1]], dtype=torch.int64)  # (1, T)
+    audio = model(tokens, tokens_lens)  # (1, T')
+
+    torchaudio.save(str("test_onnx.wav"), audio, sample_rate=22050)
+    logging.info("Saved to test_onnx.wav")
+
+
+if __name__ == "__main__":
+    formatter = "%(asctime)s %(levelname)s [%(filename)s:%(lineno)d] %(message)s"
+    logging.basicConfig(format=formatter, level=logging.INFO)
+    main()
diff --git a/egs/ljspeech/TTS/vits/text_encoder.py b/egs/ljspeech/TTS/vits/text_encoder.py
index 419fd6162..9f337e45b 100644
--- a/egs/ljspeech/TTS/vits/text_encoder.py
+++ b/egs/ljspeech/TTS/vits/text_encoder.py
@@ -30,7 +30,7 @@ from typing import Optional, Tuple
 import torch
 from torch import Tensor, nn
 
-from icefall.utils import make_pad_mask
+from icefall.utils import is_jit_tracing, make_pad_mask
 
 
 class TextEncoder(torch.nn.Module):
@@ -440,18 +440,30 @@ class RelPositionMultiheadAttention(nn.Module):
         """
         (batch_size, num_heads, seq_len, n) = x.shape
 
-        assert n == 2 * seq_len - 1, f"{n} == 2 * {seq_len} - 1"
+        if not is_jit_tracing():
+            assert n == 2 * seq_len - 1, f"{n} == 2 * {seq_len} - 1"
 
-        # Note: TorchScript requires explicit arg for stride()
-        batch_stride = x.stride(0)
-        head_stride = x.stride(1)
-        time_stride = x.stride(2)
-        n_stride = x.stride(3)
-        return x.as_strided(
-            (batch_size, num_heads, seq_len, seq_len),
-            (batch_stride, head_stride, time_stride - n_stride, n_stride),
-            storage_offset=n_stride * (seq_len - 1),
-        )
+        if is_jit_tracing():
+            rows = torch.arange(start=seq_len - 1, end=-1, step=-1)
+            cols = torch.arange(seq_len)
+            rows = rows.repeat(batch_size * num_heads).unsqueeze(-1)
+            indexes = rows + cols
+
+            x = x.reshape(-1, n)
+            x = torch.gather(x, dim=1, index=indexes)
+            x = x.reshape(batch_size, num_heads, seq_len, seq_len)
+            return x
+        else:
+            # Note: TorchScript requires explicit arg for stride()
+            batch_stride = x.stride(0)
+            head_stride = x.stride(1)
+            time_stride = x.stride(2)
+            n_stride = x.stride(3)
+            return x.as_strided(
+                (batch_size, num_heads, seq_len, seq_len),
+                (batch_stride, head_stride, time_stride - n_stride, n_stride),
+                storage_offset=n_stride * (seq_len - 1),
+            )
 
     def forward(
         self,