diff --git a/logging_json/README.rst b/logging_json/README.rst
index fcf2f9dea..f76591c02 100644
--- a/logging_json/README.rst
+++ b/logging_json/README.rst
@@ -9,6 +9,20 @@ JSON Logging
 This addon allows to output the Odoo logs in JSON.
 
 
+It also add the possibility to log extra data in json in your log.
+See documentation of json logger here : https://github.com/madzak/python-json-logger
+
+Example:
+
+.. code-block:: python
+
+   _logger.info('My Message', extra={
+       'my_extra_key_1': 'value_1',
+       'my_extra_key_2': 'value_2'})
+
+The key "extra" is a standard key of logger module so you can add this key and your log will work with or without this module (see documentation here : https://docs.python.org/2/library/logging.html#logging.Logger.debug)
+
+
 Configuration
 =============
 
@@ -18,7 +32,12 @@ The json logging is activated with the environment variable
 In order to have the logs from the start of the server, you should add
 ``logging_json`` in the ``--load`` flag or in the ``server_wide_modules``
 option in the configuration file.
-To configure this module, you need to:
+
+If you want to see the extra keys when you are developping in local
+but with the odoo logger output and not the JSON output
+you can add the environment variable ``ODOO_LOGGING_JSON_DEV`` set to ``1``.
+
+Note : ``ODOO_LOGGING_JSON_DEV`` and ``ODOO_LOGGING_JSON`` should be not set both to ``1``
 
 Known issues / Roadmap
 ======================
diff --git a/logging_json/json_log.py b/logging_json/json_log.py
index 0ed1edff3..fbac7f8f5 100644
--- a/logging_json/json_log.py
+++ b/logging_json/json_log.py
@@ -9,8 +9,10 @@ import logging
 import os
 import threading
 import re
+import json
 
 from distutils.util import strtobool
+from openerp.netsvc import ColoredFormatter
 
 _logger = logging.getLogger(__name__)
 
@@ -73,8 +75,29 @@ class OdooJsonFormatter(jsonlogger.JsonFormatter):
         return res
 
 
+class OdooJsonDevFormatter(ColoredFormatter):
+
+    def format(self, record):
+        response = super(OdooJsonDevFormatter, self).format(record)
+        extra = {}
+        RESERVED_ATTRS = list(jsonlogger.RESERVED_ATTRS) + ["dbname", "pid"]
+        for key, value in record.__dict__.items():
+            if (key not in RESERVED_ATTRS and not
+                    (hasattr(key, "startswith") and key.startswith('_'))):
+                extra[key] = value
+        if extra:
+            response += " extra: " + json.dumps(
+                extra, indent=4, sort_keys=True)
+        return response
+
+
 if is_true(os.environ.get('ODOO_LOGGING_JSON')):
     format = ('%(asctime)s %(pid)s %(levelname)s'
               '%(dbname)s %(name)s: %(message)s')
     formatter = OdooJsonFormatter(format)
     logging.getLogger().handlers[0].formatter = formatter
+elif is_true(os.environ.get('ODOO_LOGGING_JSON_DEV')):
+    format = ('%(asctime)s %(pid)s %(levelname)s'
+              '%(dbname)s %(name)s: %(message)s')
+    formatter = OdooJsonDevFormatter(format)
+    logging.getLogger().handlers[0].formatter = formatter