diff --git a/tests/test_converters.py b/tests/test_converters.py
new file mode 100644
index 0000000..a1cf1b7
--- /dev/null
+++ b/tests/test_converters.py
@@ -0,0 +1,116 @@
+"""Tests for the converter module."""
+
+import json
+import pytest
+
+from configconverter.converters import Converter
+from configconverter.exceptions import ParseError, InvalidFormatError, UnsupportedConversionError
+
+
+class TestConverter:
+    """Tests for the Converter class."""
+
+    @pytest.fixture
+    def converter(self):
+        return Converter()
+
+    def test_detect_json_format(self, converter):
+        content = '{"name": "test", "value": 123}'
+        assert converter.detect_format(content) == "json"
+
+    def test_detect_json_array(self, converter):
+        content = '[{"id": 1}, {"id": 2}]'
+        assert converter.detect_format(content) == "json"
+
+    def test_detect_yaml_format(self, converter):
+        content = 'name: test\nvalue: 123\n'
+        assert converter.detect_format(content) == "yaml"
+
+    def test_detect_toml_format(self, converter):
+        content = 'name = "test"\nvalue = 123\n'
+        result = converter.detect_format(content)
+        assert result in ("toml", "yaml")
+
+    def test_convert_json_to_yaml(self, converter):
+        json_content = '{"name": "test", "value": 123}'
+        result = converter.convert(json_content, "json", "yaml")
+        assert "name: test" in result
+        assert "value: 123" in result
+
+    def test_convert_json_to_toml(self, converter):
+        json_content = '{"name": "test", "value": 123}'
+        result = converter.convert(json_content, "json", "toml")
+        assert 'name = "test"' in result
+        assert "value = 123" in result
+
+    def test_convert_yaml_to_json(self, converter):
+        yaml_content = 'name: test\nvalue: 123\n'
+        result = converter.convert(yaml_content, "yaml", "json")
+        data = json.loads(result)
+        assert data["name"] == "test"
+        assert data["value"] == 123
+
+    def test_convert_yaml_to_toml(self, converter):
+        yaml_content = 'name: test\nvalue: 123\n'
+        result = converter.convert(yaml_content, "yaml", "toml")
+        assert 'name = "test"' in result
+
+    def test_convert_toml_to_json(self, converter):
+        toml_content = 'name = "test"\nvalue = 123\n'
+        result = converter.convert(toml_content, "toml", "json")
+        data = json.loads(result)
+        assert data["name"] == "test"
+        assert data["value"] == 123
+
+    def test_convert_toml_to_yaml(self, converter):
+        toml_content = 'name = "test"\nvalue = 123\n'
+        result = converter.convert(toml_content, "toml", "yaml")
+        assert "name: test" in result
+
+    def test_invalid_json_syntax(self, converter):
+        content = '{"name": "test",}'
+        with pytest.raises(ParseError):
+            converter.convert(content, "json", "yaml")
+
+    def test_invalid_yaml_syntax(self, converter):
+        content = "name: test\n  value: 123\n"
+        with pytest.raises(ParseError):
+            converter.convert(content, "yaml", "json")
+
+    def test_invalid_toml_syntax(self, converter):
+        content = 'name = "test"\nvalue = 123\ninvalid line here\n'
+        with pytest.raises(ParseError):
+            converter.convert(content, "toml", "json")
+
+    def test_unsupported_format(self, converter):
+        content = "some random text that is not valid"
+        try:
+            converter.detect_format(content)
+        except (InvalidFormatError, Exception):
+            pass
+
+    def test_unsupported_conversion_direction(self, converter):
+        content = '{"name": "test"}'
+        with pytest.raises(UnsupportedConversionError):
+            converter.convert(content, "json", "xml")
+
+    def test_nested_structure_json_to_yaml(self, converter):
+        json_content = json.dumps({
+            "server": {
+                "host": "localhost",
+                "port": 8080
+            },
+            "databases": [
+                {"name": "db1", "enabled": True},
+                {"name": "db2", "enabled": False}
+            ]
+        })
+        result = converter.convert(json_content, "json", "yaml")
+        assert "server:" in result
+        assert "host: localhost" in result
+        assert "databases:" in result
+
+    def test_case_insensitive_format(self, converter):
+        json_content = '{"name": "test"}'
+        result = converter.convert(json_content, "JSON", "YAML")
+        assert "name: test" in result