diff --git a/docs/configuration.rst b/docs/configuration.rst
index 1c7611ba..36a0f4be 100644
--- a/docs/configuration.rst
+++ b/docs/configuration.rst
@@ -4240,6 +4240,20 @@ Description
     Note: Only applies for ``"mode": "custom"``.
 
 
+metadata.ascii
+--------------
+Type
+    ``bool``
+Default
+    ``false``
+Description
+    Escape all non-ASCII characters.
+
+    See the ``ensure_ascii`` argument of |json.dump()|_ for further details.
+
+    Note: Only applies for ``"mode": "json"`` and ``"jsonl"``.
+
+
 metadata.indent
 ---------------
 Type
@@ -4255,6 +4269,35 @@ Description
     Note: Only applies for ``"mode": "json"``.
 
 
+metadata.separators
+-------------------
+Type
+    ``list`` with two ``string`` elements
+Default
+    ``[", ", ": "]``
+Description
+    ``<item separator>`` - ``<key separator>`` pair
+    to separate JSON keys and values with.
+
+    See the ``separators`` argument of |json.dump()|_ for further details.
+
+    Note: Only applies for ``"mode": "json"`` and ``"jsonl"``.
+
+
+metadata.sort
+-------------
+Type
+    ``bool``
+Default
+    ``false``
+Description
+    Sort output by `key`.
+
+    See the ``sort_keys`` argument of |json.dump()|_ for further details.
+
+    Note: Only applies for ``"mode": "json"`` and ``"jsonl"``.
+
+
 metadata.open
 -------------
 Type
diff --git a/gallery_dl/postprocessor/metadata.py b/gallery_dl/postprocessor/metadata.py
index cac78b79..3f5d1d6f 100644
--- a/gallery_dl/postprocessor/metadata.py
+++ b/gallery_dl/postprocessor/metadata.py
@@ -47,20 +47,12 @@ class MetadataPP(PostProcessor):
             ext = "txt"
         elif mode == "jsonl":
             self.write = self._write_json
-            self._json_encode = json.JSONEncoder(
-                ensure_ascii=options.get("ascii", False),
-                sort_keys=True, indent=None, default=str,
-            ).encode
+            self._json_encode = self._make_encoder(options).encode
             omode = "a"
             filename = "data.jsonl"
         else:
             self.write = self._write_json
-            self._json_encode = json.JSONEncoder(
-                ensure_ascii=options.get("ascii", False),
-                indent=options.get("indent", 4),
-                sort_keys=True,
-                default=str,
-            ).encode
+            self._json_encode = self._make_encoder(options, 4).encode
             ext = "json"
 
         directory = options.get("directory")
@@ -200,5 +192,15 @@ class MetadataPP(PostProcessor):
             kwdict = util.filter_dict(kwdict)
         fp.write(self._json_encode(kwdict) + "\n")
 
+    @staticmethod
+    def _make_encoder(options, indent=None):
+        return json.JSONEncoder(
+            ensure_ascii=options.get("ascii", False),
+            sort_keys=options.get("sort", False),
+            separators=options.get("separators"),
+            indent=options.get("indent", indent),
+            check_circular=False, default=str,
+        )
+
 
 __postprocessor__ = MetadataPP
diff --git a/test/test_postprocessor.py b/test/test_postprocessor.py
index 63dcfc57..136a0e02 100644
--- a/test/test_postprocessor.py
+++ b/test/test_postprocessor.py
@@ -176,13 +176,11 @@ class MetadataTest(BasePostprocessorTest):
 
     def test_metadata_json(self):
         pp = self._create({
-            "mode"     : "json",
-            "ascii"    : True,
-            "indent"   : 2,
-            "extension": "JSON",
+            "mode"      : "json",
+            "extension" : "JSON",
         }, {
-            "public"   : "hello ワールド",
-            "_private" : "foo バール",
+            "public"    : "hello ワールド",
+            "_private"  : "foo バー",
         })
 
         self.assertEqual(pp.write    , pp._write_json)
@@ -194,26 +192,31 @@ class MetadataTest(BasePostprocessorTest):
 
         path = self.pathfmt.realpath + ".JSON"
         m.assert_called_once_with(path, "w", encoding="utf-8")
-        self.assertEqual(self._output(m), r"""{
-  "category": "test",
-  "extension": "ext",
-  "filename": "file",
-  "public": "hello \u30ef\u30fc\u30eb\u30c9"
+
+        if sys.hexversion >= 0x3060000:
+            # python 3.4 & 3.5 have random order without 'sort: True'
+            self.assertEqual(self._output(m), """{
+    "category": "test",
+    "filename": "file",
+    "extension": "ext",
+    "public": "hello ワールド"
 }
 """)
 
     def test_metadata_json_options(self):
         pp = self._create({
-            "mode"     : "json",
-            "ascii"    : False,
-            "private"  : True,
-            "indent"   : None,
-            "open"     : "a",
-            "encoding" : "UTF-8",
-            "extension": "JSON",
+            "mode"      : "json",
+            "ascii"     : True,
+            "sort"      : True,
+            "separators": [",", " : "],
+            "private"   : True,
+            "indent"    : None,
+            "open"      : "a",
+            "encoding"  : "UTF-8",
+            "extension" : "JSON",
         }, {
-            "public"   : "hello ワールド",
-            "_private" : "foo バール",
+            "public"    : "hello ワールド",
+            "_private"  : "foo バー",
         })
 
         self.assertEqual(pp.write    , pp._write_json)
@@ -226,11 +229,11 @@ class MetadataTest(BasePostprocessorTest):
         path = self.pathfmt.realpath + ".JSON"
         m.assert_called_once_with(path, "a", encoding="UTF-8")
         self.assertEqual(self._output(m), """{\
-"_private": "foo バール", \
-"category": "test", \
-"extension": "ext", \
-"filename": "file", \
-"public": "hello ワールド"}
+"_private" : "foo \\u30d0\\u30fc",\
+"category" : "test",\
+"extension" : "ext",\
+"filename" : "file",\
+"public" : "hello \\u30ef\\u30fc\\u30eb\\u30c9"}
 """)
 
     def test_metadata_tags(self):
@@ -363,7 +366,7 @@ class MetadataTest(BasePostprocessorTest):
         m.assert_called_once_with(path, "w", encoding="utf-8")
 
     def test_metadata_stdout(self):
-        self._create({"filename": "-", "indent": None})
+        self._create({"filename": "-", "indent": None, "sort": True})
 
         with patch("sys.stdout", Mock()) as m:
             self._trigger()