diff --git a/deepspeech/exps/deepspeech2/bin/test_hub.py b/deepspeech/exps/deepspeech2/bin/test_hub.py
index 7d98e0b1..38760c28 100644
--- a/deepspeech/exps/deepspeech2/bin/test_hub.py
+++ b/deepspeech/exps/deepspeech2/bin/test_hub.py
@@ -58,8 +58,7 @@ class DeepSpeech2Tester_hub():
             num_processes=cfg.num_proc_bsearch)
         #replace the '<space>' with ' '
         result_transcripts = [
-            self._text_featurizer.detokenize(sentence)
-            for sentence in result_transcripts
+            sentence.replace("<space>", " ") for sentence in result_transcripts
         ]
 
         return result_transcripts
@@ -167,9 +166,8 @@ def check(audio_file):
 
 def main_sp(config, args):
     exp = DeepSpeech2Tester_hub(config, args)
-    with exp.eval():
-        exp.setup()
-        exp.run_test()
+    exp.setup()
+    exp.run_test()
 
 
 def main(config, args):
diff --git a/deepspeech/exps/u2/bin/test_hub.py b/deepspeech/exps/u2/bin/test_hub.py
new file mode 100644
index 00000000..8c006ebe
--- /dev/null
+++ b/deepspeech/exps/u2/bin/test_hub.py
@@ -0,0 +1,187 @@
+# Copyright (c) 2021 PaddlePaddle Authors. All Rights Reserved.
+#
+# 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.
+"""Evaluation for U2 model."""
+import cProfile
+import os
+import sys
+
+import paddle
+import soundfile
+
+from deepspeech.exps.u2.config import get_cfg_defaults
+from deepspeech.frontend.featurizer.text_featurizer import TextFeaturizer
+from deepspeech.io.collator import SpeechCollator
+from deepspeech.models.u2 import U2Model
+from deepspeech.training.cli import default_argument_parser
+from deepspeech.training.trainer import Trainer
+from deepspeech.utils import layer_tools
+from deepspeech.utils import mp_tools
+from deepspeech.utils.log import Log
+from deepspeech.utils.utility import print_arguments
+from deepspeech.utils.utility import UpdateConfig
+logger = Log(__name__).getlog()
+
+# TODO(hui zhang): dynamic load
+
+
+class U2Tester_Hub(Trainer):
+    def __init__(self, config, args):
+        # super().__init__(config, args)
+        self.args = args
+        self.config = config
+        self.audio_file = args.audio_file
+        self.collate_fn_test = SpeechCollator.from_config(config)
+        self._text_featurizer = TextFeaturizer(
+            unit_type=config.collator.unit_type,
+            vocab_filepath=None,
+            spm_model_prefix=config.collator.spm_model_prefix)
+
+    def setup_model(self):
+        config = self.config
+        model_conf = config.model
+
+        with UpdateConfig(model_conf):
+            model_conf.input_dim = self.collate_fn_test.feature_size
+            model_conf.output_dim = self.collate_fn_test.vocab_size
+
+        model = U2Model.from_config(model_conf)
+
+        if self.parallel:
+            model = paddle.DataParallel(model)
+
+        logger.info(f"{model}")
+        layer_tools.print_params(model, logger.info)
+
+        self.model = model
+        logger.info("Setup model")
+
+    @mp_tools.rank_zero_only
+    @paddle.no_grad()
+    def test(self):
+        self.model.eval()
+        cfg = self.config.decoding
+        audio_file = self.audio_file
+        collate_fn_test = self.collate_fn_test
+        audio, _ = collate_fn_test.process_utterance(
+            audio_file=audio_file, transcript="Hello")
+        audio_len = audio.shape[0]
+        audio = paddle.to_tensor(audio, dtype='float32')
+        audio_len = paddle.to_tensor(audio_len)
+        audio = paddle.unsqueeze(audio, axis=0)
+        vocab_list = collate_fn_test.vocab_list
+
+        text_feature = self.collate_fn_test.text_feature
+        result_transcripts = self.model.decode(
+            audio,
+            audio_len,
+            text_feature=text_feature,
+            decoding_method=cfg.decoding_method,
+            lang_model_path=cfg.lang_model_path,
+            beam_alpha=cfg.alpha,
+            beam_beta=cfg.beta,
+            beam_size=cfg.beam_size,
+            cutoff_prob=cfg.cutoff_prob,
+            cutoff_top_n=cfg.cutoff_top_n,
+            num_processes=cfg.num_proc_bsearch,
+            ctc_weight=cfg.ctc_weight,
+            decoding_chunk_size=cfg.decoding_chunk_size,
+            num_decoding_left_chunks=cfg.num_decoding_left_chunks,
+            simulate_streaming=cfg.simulate_streaming)
+        logger.info("The result_transcripts: " + result_transcripts[0][0])
+
+    def run_test(self):
+        self.resume()
+        try:
+            self.test()
+        except KeyboardInterrupt:
+            sys.exit(-1)
+
+    def setup(self):
+        """Setup the experiment.
+        """
+        paddle.set_device('gpu' if self.args.nprocs > 0 else 'cpu')
+
+        #self.setup_output_dir()
+        #self.setup_checkpointer()
+
+        #self.setup_dataloader()
+        self.setup_model()
+
+        self.iteration = 0
+        self.epoch = 0
+
+    def resume(self):
+        """Resume from the checkpoint at checkpoints in the output
+        directory or load a specified checkpoint.
+        """
+        params_path = self.args.checkpoint_path + ".pdparams"
+        model_dict = paddle.load(params_path)
+        self.model.set_state_dict(model_dict)
+
+
+def check(audio_file):
+    logger.info("checking the audio file format......")
+    try:
+        sig, sample_rate = soundfile.read(audio_file)
+    except Exception as e:
+        logger.error(str(e))
+        logger.error(
+            "can not open the wav file, please check the audio file format")
+        sys.exit(-1)
+    logger.info("The sample rate is %d" % sample_rate)
+    assert (sample_rate == 16000)
+    logger.info("The audio file format is right")
+
+
+def main_sp(config, args):
+    exp = U2Tester_Hub(config, args)
+    with exp.eval():
+        exp.setup()
+        exp.run_test()
+
+
+def main(config, args):
+    main_sp(config, args)
+
+
+if __name__ == "__main__":
+    parser = default_argument_parser()
+    # save asr result to
+    parser.add_argument(
+        "--result_file", type=str, help="path of save the asr result")
+    parser.add_argument(
+        "--audio_file", type=str, help="path of the input audio file")
+    args = parser.parse_args()
+    print_arguments(args, globals())
+
+    if not os.path.isfile(args.audio_file):
+        print("Please input the right audio file path")
+        sys.exit(-1)
+    check(args.audio_file)
+    # https://yaml.org/type/float.html
+    config = get_cfg_defaults()
+    if args.config:
+        config.merge_from_file(args.config)
+    if args.opts:
+        config.merge_from_list(args.opts)
+    config.freeze()
+    print(config)
+    if args.dump_config:
+        with open(args.dump_config, 'w') as f:
+            print(config, file=f)
+
+    # Setting for profiling
+    pr = cProfile.Profile()
+    pr.runcall(main, config, args)
+    pr.dump_stats('test.profile')
diff --git a/examples/aishell/s1/local/test_hub.sh b/examples/aishell/s1/local/test_hub.sh
new file mode 100755
index 00000000..99b141c8
--- /dev/null
+++ b/examples/aishell/s1/local/test_hub.sh
@@ -0,0 +1,47 @@
+#!/bin/bash
+
+if [ $# != 3 ];then
+    echo "usage: ${0} config_path ckpt_path_prefix audio_file"
+    exit -1
+fi
+
+ngpu=$(echo $CUDA_VISIBLE_DEVICES | awk -F "," '{print NF}')
+echo "using $ngpu gpus..."
+
+config_path=$1
+ckpt_prefix=$2
+audio_file=$3
+
+chunk_mode=false
+if [[ ${config_path} =~ ^.*chunk_.*yaml$ ]];then
+    chunk_mode=true
+fi
+
+# download language model
+#bash local/download_lm_ch.sh
+#if [ $? -ne 0 ]; then
+#    exit 1
+#fi
+
+
+
+for type in  attention_rescoring; do
+    echo "decoding ${type}"
+    batch_size=1
+    output_dir=${ckpt_prefix}
+    mkdir -p ${output_dir}
+    python3 -u ${BIN_DIR}/test_hub.py \
+    --nproc ${ngpu} \
+    --config ${config_path} \
+    --result_file ${output_dir}/${type}.rsl \
+    --checkpoint_path ${ckpt_prefix} \
+    --opts decoding.decoding_method ${type} \
+    --opts decoding.batch_size ${batch_size} \
+    --audio_file ${audio_file}
+
+    if [ $? -ne 0 ]; then
+        echo "Failed in evaluation!"
+        exit 1
+    fi
+done
+exit 0
diff --git a/examples/aishell/s1/run.sh b/examples/aishell/s1/run.sh
index 054fdd46..126c8e4e 100644
--- a/examples/aishell/s1/run.sh
+++ b/examples/aishell/s1/run.sh
@@ -13,6 +13,8 @@ avg_ckpt=avg_${avg_num}
 ckpt=$(basename ${conf_path} | awk -F'.' '{print $1}')
 echo "checkpoint name ${ckpt}"
 
+audio_file="data/tmp.wav"
+
 if [ ${stage} -le 0 ] && [ ${stop_stage} -ge 0 ]; then
     # prepare data
     bash ./local/data.sh || exit -1
@@ -48,3 +50,8 @@ fi
     # train lm and build TLG
     ./local/tlg.sh --corpus aishell --lmtype srilm
  fi
+
+if [ ${stage} -le 7 ] && [ ${stop_stage} -ge 7 ]; then
+    # test a single .wav file
+    CUDA_VISIBLE_DEVICES=3 ./local/test_hub.sh ${conf_path} exp/${ckpt}/checkpoints/${avg_ckpt} ${audio_file} || exit -1
+fi
diff --git a/examples/librispeech/s0/local/test_hub.sh b/examples/librispeech/s0/local/test_hub.sh
new file mode 100755
index 00000000..2e32f24a
--- /dev/null
+++ b/examples/librispeech/s0/local/test_hub.sh
@@ -0,0 +1,36 @@
+#!/bin/bash
+
+if [ $# != 4 ];then
+    echo "usage: ${0} config_path ckpt_path_prefix model_type audio_file"
+    exit -1
+fi
+
+ngpu=$(echo $CUDA_VISIBLE_DEVICES | awk -F "," '{print NF}')
+echo "using $ngpu gpus..."
+
+config_path=$1
+ckpt_prefix=$2
+model_type=$3
+audio_file=$4
+
+# download language model
+bash local/download_lm_en.sh
+if [ $? -ne 0 ]; then
+   exit 1
+fi
+
+python3 -u ${BIN_DIR}/test_hub.py \
+--nproc ${ngpu} \
+--config ${config_path} \
+--result_file ${ckpt_prefix}.rsl \
+--checkpoint_path ${ckpt_prefix} \
+--model_type ${model_type} \
+--audio_file ${audio_file}
+
+if [ $? -ne 0 ]; then
+    echo "Failed in evaluation!"
+    exit 1
+fi
+
+
+exit 0
diff --git a/examples/librispeech/s0/run.sh b/examples/librispeech/s0/run.sh
index af47fb9b..385a24a4 100755
--- a/examples/librispeech/s0/run.sh
+++ b/examples/librispeech/s0/run.sh
@@ -13,6 +13,7 @@ avg_ckpt=avg_${avg_num}
 ckpt=$(basename ${conf_path} | awk -F'.' '{print $1}')
 echo "checkpoint name ${ckpt}"
 
+audio_file="data/tmp.flac"
 if [ ${stage} -le 0 ] && [ ${stop_stage} -ge 0 ]; then
     # prepare data
     bash ./local/data.sh || exit -1
@@ -37,3 +38,8 @@ if [ ${stage} -le 4 ] && [ ${stop_stage} -ge 4 ]; then
     # export ckpt avg_n
     CUDA_VISIBLE_DEVICES= ./local/export.sh ${conf_path} exp/${ckpt}/checkpoints/${avg_ckpt} exp/${ckpt}/checkpoints/${avg_ckpt}.jit ${model_type}
 fi
+
+if [ ${stage} -le 5 ] && [ ${stop_stage} -ge 5 ]; then
+    # test a single .wav file
+    CUDA_VISIBLE_DEVICES=3 ./local/test_hub.sh ${conf_path} exp/${ckpt}/checkpoints/${avg_ckpt} ${model_type} ${audio_file} || exit -1
+fi
diff --git a/examples/librispeech/s1/local/test_hub.sh b/examples/librispeech/s1/local/test_hub.sh
new file mode 100755
index 00000000..dcf242e9
--- /dev/null
+++ b/examples/librispeech/s1/local/test_hub.sh
@@ -0,0 +1,54 @@
+#!/bin/bash
+
+if [ $# != 3 ];then
+    echo "usage: ${0} config_path ckpt_path_prefix audio_file"
+    exit -1
+fi
+
+ngpu=$(echo $CUDA_VISIBLE_DEVICES | awk -F "," '{print NF}')
+echo "using $ngpu gpus..."
+
+config_path=$1
+ckpt_prefix=$2
+audio_file=$3
+
+# bpemode (unigram or bpe)
+nbpe=5000
+bpemode=unigram
+bpeprefix="data/bpe_${bpemode}_${nbpe}"
+bpemodel=${bpeprefix}.model
+
+chunk_mode=false
+if [[ ${config_path} =~ ^.*chunk_.*yaml$ ]];then
+    chunk_mode=true
+fi
+
+# download language model
+#bash local/download_lm_ch.sh
+#if [ $? -ne 0 ]; then
+#    exit 1
+#fi
+
+
+for type in attention_rescoring; do
+    echo "decoding ${type}"
+    batch_size=1
+    output_dir=${ckpt_prefix}
+    mkdir -p ${output_dir}
+    python3 -u ${BIN_DIR}/test_hub.py \
+    --nproc ${ngpu} \
+    --config ${config_path} \
+    --result_file ${output_dir}/${type}.rsl \
+    --checkpoint_path ${ckpt_prefix} \
+    --opts decoding.decoding_method ${type} \
+    --opts decoding.batch_size ${batch_size} \
+    --audio_file ${audio_file}
+
+    #score_sclite.sh --bpe ${nbpe} --bpemodel ${bpemodel}.model --wer true ${expdir}/${decode_dir} ${dict}
+    if [ $? -ne 0 ]; then
+        echo "Failed in evaluation!"
+        exit 1
+    fi
+done
+
+exit 0
diff --git a/examples/librispeech/s1/run.sh b/examples/librispeech/s1/run.sh
index 4c8bf514..9ea93430 100755
--- a/examples/librispeech/s1/run.sh
+++ b/examples/librispeech/s1/run.sh
@@ -15,6 +15,8 @@ avg_ckpt=avg_${avg_num}
 ckpt=$(basename ${conf_path} | awk -F'.' '{print $1}')
 echo "checkpoint name ${ckpt}"
 
+audio_file="data/tmp.flac"
+
 if [ ${stage} -le 0 ] && [ ${stop_stage} -ge 0 ]; then
     # prepare data
     bash ./local/data.sh || exit -1
@@ -44,3 +46,8 @@ if [ ${stage} -le 5 ] && [ ${stop_stage} -ge 5 ]; then
     # export ckpt avg_n
     CUDA_VISIBLE_DEVICES= ./local/export.sh ${conf_path} exp/${ckpt}/checkpoints/${avg_ckpt} exp/${ckpt}/checkpoints/${avg_ckpt}.jit
 fi
+
+if [ ${stage} -le 6 ] && [ ${stop_stage} -ge 6 ]; then
+    # test a single .wav file
+    CUDA_VISIBLE_DEVICES=3 ./local/test_hub.sh ${conf_path} exp/${ckpt}/checkpoints/${avg_ckpt} ${audio_file} || exit -1
+fi