diff --git a/tests/test_converters/test_json.py b/tests/test_converters/test_json.py
new file mode 100644
index 0000000..3cc5848
--- /dev/null
+++ b/tests/test_converters/test_json.py
@@ -0,0 +1,78 @@
+"""Tests for JSON converter."""
+
+import pytest
+import json
+import tempfile
+import os
+from pathlib import Path
+
+from config_convert.converters import JSONConverter
+
+
+class TestJSONConverter:
+    @pytest.fixture
+    def converter(self):
+        return JSONConverter()
+
+    def test_loads_valid_json(self, converter):
+        data = '{"name": "test", "value": 123}'
+        result = converter.loads(data)
+        assert result == {"name": "test", "value": 123}
+
+    def test_loads_nested_json(self, converter):
+        data = '{"database": {"host": "localhost", "port": 5432}}'
+        result = converter.loads(data)
+        assert result == {"database": {"host": "localhost", "port": 5432}}
+
+    def test_loads_array_json(self, converter):
+        data = '{"tags": ["a", "b", "c"]}'
+        result = converter.loads(data)
+        assert result == {"tags": ["a", "b", "c"]}
+
+    def test_dumps_basic_dict(self, converter):
+        data = {"name": "test", "value": 123}
+        result = converter.dumps(data)
+        parsed = json.loads(result)
+        assert parsed == data
+
+    def test_dumps_with_custom_indent(self, converter):
+        data = {"name": "test"}
+        result = converter.dumps(data, indent=4)
+        assert "\n" in result
+
+    def test_dumps_nested_dict(self, converter):
+        data = {"database": {"host": "localhost", "port": 5432}}
+        result = converter.dumps(data)
+        parsed = json.loads(result)
+        assert parsed == data
+
+    def test_roundtrip(self, converter):
+        original = {"name": "test", "version": "1.0.0", "enabled": True, "count": 42}
+        dumped = converter.dumps(original)
+        loaded = converter.loads(dumped)
+        assert loaded == original
+
+    def test_load_file(self, converter, temp_file, sample_json):
+        gen = temp_file(json.dumps(sample_json), suffix=".json")
+        path = next(gen)
+        try:
+            result = converter.load(path)
+            assert result == sample_json
+        finally:
+            import os
+            os.unlink(path)
+
+    def test_dump_file(self, converter, temp_dir, sample_json):
+        import shutil
+        path = tempfile.mktemp(suffix=".json")
+        try:
+            converter.dump(sample_json, path)
+            result = json.loads(Path(path).read_text())
+            assert result == sample_json
+        finally:
+            if Path(path).exists():
+                os.unlink(path)
+
+    def test_invalid_json_raises(self, converter):
+        with pytest.raises(json.JSONDecodeError):
+            converter.loads("{invalid json}")