diff --git a/generic_trainer/__init__.py b/generic_trainer/__init__.py
index a0013e9..bc5a08b 100644
--- a/generic_trainer/__init__.py
+++ b/generic_trainer/__init__.py
@@ -1,2 +1,3 @@
 from generic_trainer.trainer import *
+from generic_trainer.tester import *
 import generic_trainer.metrics
diff --git a/generic_trainer/configs.py b/generic_trainer/configs.py
index 71501ca..d69e79a 100644
--- a/generic_trainer/configs.py
+++ b/generic_trainer/configs.py
@@ -125,6 +125,9 @@ class Config(OptionContainer):
     dataset: Optional[Dataset] = None
     """The dataset object."""
 
+    pred_names: Any = ('cs', 'eg', 'sg')
+    """Names of the quantities predicted by the model."""
+
     debug: bool = False
 
     cpu_only: bool = False
@@ -144,15 +147,22 @@ class InferenceConfig(Config):
     # ===== PtychoNN configs =====
     batch_size: int = 1
 
-    model_path: str = None
-    """Path to a trained PtychoNN model."""
+    pretrained_model_path: str = None
+    """Path to a trained model."""
 
     prediction_output_path: str = None
-    """Path to save PtychoNN prediction results."""
+    """Path to save prediction results."""
+
+    load_pretrained_encoder_only: bool = False
+    """Keep this False for testing."""
+
+    batch_size_per_process: int = 64
+    """The batch size per process."""
 
 
 @dataclasses.dataclass
 class TrainingConfig(Config):
+
     training_dataset: Optional[Dataset] = None
     """
     The training dataset. If this is None, then the whole dataset (including training and validation) must be
@@ -218,9 +228,6 @@ class TrainingConfig(Config):
     load_pretrained_encoder_only: bool = False
     """If True, only the pretrained encoder (backbone) will be loaded if `pretrained_model_path` is not None."""
 
-    pred_names: Any = ('cs', 'eg', 'sg')
-    """Names of the quantities predicted by the model."""
-
     validation_ratio: float = 0.1
     """Ratio of data to be used as validation set."""
 
diff --git a/generic_trainer/tester.py b/generic_trainer/tester.py
new file mode 100644
index 0000000..3fd36d0
--- /dev/null
+++ b/generic_trainer/tester.py
@@ -0,0 +1,68 @@
+import os
+
+import torch
+from torch.utils.data import Dataset, DataLoader
+
+import generic_trainer.trainer as trainer
+from generic_trainer.configs import *
+
+
+class Tester(trainer.Trainer):
+
+    def __init__(self, configs: InferenceConfig):
+        super().__init__(configs, skip_init=True)
+        self.rank = 0
+        self.num_processes = 1
+        self.gatekeeper = None
+        self.dataset = None
+        self.sampler = None
+        self.dataloader = None
+
+    def build(self):
+        self.build_ranks()
+        self.build_scalable_parameters()
+        self.build_device()
+        self.build_dataset()
+        self.build_dataloaders()
+        self.build_model()
+        self.build_dir()
+
+    def build_scalable_parameters(self):
+        self.all_proc_batch_size = self.configs.batch_size_per_process * self.num_processes
+
+    def build_dataset(self):
+        self.dataset = self.configs.dataset
+
+    def build_dataloaders(self):
+        if self.parallelization_type == 'multi_node':
+            self.sampler = torch.utils.data.distributed.DistributedSampler(self.training_dataset,
+                                                                           num_replicas=self.num_processes,
+                                                                           rank=self.rank,
+                                                                           drop_last=False,
+                                                                           shuffle=False)
+            self.dataloader = DataLoader(self.dataset,
+                                         batch_size=self.configs.batch_size_per_process,
+                                         sampler=self.sampler,
+                                         collate_fn=lambda x: x)
+        else:
+            self.dataloader = DataLoader(self.training_dataset, shuffle=False,
+                                         batch_size=self.all_proc_batch_size,
+                                         collate_fn=lambda x: x, worker_init_fn=self.get_worker_seed_func(),
+                                         generator=self.get_dataloader_generator(), num_workers=0,
+                                         drop_last=False)
+
+    def build_dir(self):
+        if self.gatekeeper.should_proceed(gate_kept=True):
+            if not os.path.exists(self.configs.prediction_output_path):
+                os.makedirs(self.configs.prediction_output_path)
+        self.barrier()
+
+    def run(self):
+        self.model.eval()
+        for j, data_and_labels in enumerate(self.dataloader):
+            data, _ = self.process_data_loader_yield(data_and_labels)
+            preds = self.model(*data)
+            self.save_predictions(preds)
+
+    def save_predictions(self, preds):
+        pass
diff --git a/generic_trainer/trainer.py b/generic_trainer/trainer.py
index a32dd7d..35339ae 100644
--- a/generic_trainer/trainer.py
+++ b/generic_trainer/trainer.py
@@ -1,6 +1,6 @@
 import logging
 import os
-from typing import Optional, Any
+from typing import Optional, Any, Union
 import itertools
 import copy
 import re
@@ -231,7 +231,8 @@ def dump(self, path):
 
 class Trainer:
 
-    def __init__(self, configs: TrainingConfig, rank=None, num_processes=None, *args, **kwargs):
+    def __init__(self, configs: Union[TrainingConfig, Config], rank=None, num_processes=None, skip_init=False,
+                 *args, **kwargs):
         """
         Trainer constructor.
 
@@ -244,6 +245,8 @@ def __init__(self, configs: TrainingConfig, rank=None, num_processes=None, *args
                               None unless multi_node is intended and training is run using torch.multiprocessing.spawn.
         """
         self.configs = configs
+        if skip_init:
+            return
         self.parallelization_type = self.configs.parallelization_params.parallelization_type
         self.dataset = self.configs.dataset
         self.training_dataset = None