diff --git a/chat_downloader/chat_downloader.py b/chat_downloader/chat_downloader.py
index 0ce16d3..db8f1e4 100644
--- a/chat_downloader/chat_downloader.py
+++ b/chat_downloader/chat_downloader.py
@@ -95,6 +95,7 @@ def get_chat(self, url=None,
 
                  # Output
                  output=None,
+                 output_format=None,
                  overwrite=True,
                  sort_keys=True,
                  indent=4,
@@ -149,6 +150,8 @@ def get_chat(self, url=None,
         :param output: Path of the output file, defaults to None (print to
             standard output)
         :type output: str, optional
+        :param output_format: The output file format, like 'jsonl', 'txt', etc.
+        :type output_format: str, optional
         :param overwrite: If True, overwrite output file. Otherwise, append
             to the end of the file. Defaults to True. In both cases, the file
             (and directories) is created if it does not exist.
@@ -266,6 +269,7 @@ def log_on_inactivity_timeout():
                         indent=params['indent'],
                         sort_keys=params['sort_keys'],
                         overwrite=params['overwrite'],
+                        format=params['output_format'],
                         lazy_initialise=True
                     ))
 
diff --git a/chat_downloader/cli.py b/chat_downloader/cli.py
index 3fa035b..fc54617 100644
--- a/chat_downloader/cli.py
+++ b/chat_downloader/cli.py
@@ -139,6 +139,7 @@ def add_init_param(group, *keys, **kwargs):
 
     output_group = parser.add_argument_group('Output Arguments')
     add_chat_param(output_group, '--output', '-o')
+    add_chat_param(output_group, '--output_format', '-of')
     add_chat_param(output_group, '--overwrite',
                    type=str2bool, nargs='?', const=True)
     add_chat_param(output_group, '--sort_keys',