diff --git a/app/tests/test_parsers.py b/app/tests/test_parsers.py
new file mode 100644
index 0000000..3678155
--- /dev/null
+++ b/app/tests/test_parsers.py
@@ -0,0 +1,208 @@
+"""Tests for config parsers."""
+
+import pytest
+import json
+import tempfile
+from pathlib import Path
+
+from src.confgen.parsers import ConfigParser
+
+
+class TestConfigParser:
+    """Tests for ConfigParser."""
+
+    def setup_method(self):
+        """Set up test fixtures."""
+        self.parser = ConfigParser()
+
+    def test_parse_json(self):
+        """Test parsing JSON content."""
+        content = '{"name": "myapp", "port": 8080}'
+        result = self.parser.parse_json(content)
+
+        assert result["name"] == "myapp"
+        assert result["port"] == 8080
+
+    def test_parse_yaml(self):
+        """Test parsing YAML content."""
+        content = """
+name: myapp
+port: 8080
+features:
+  - feature1
+  - feature2
+"""
+        result = self.parser.parse_yaml(content)
+
+        assert result["name"] == "myapp"
+        assert result["port"] == 8080
+        assert "feature1" in result["features"]
+
+    def test_parse_toml(self):
+        """Test parsing TOML content."""
+        content = """
+name = "myapp"
+port = 8080
+
+[features]
+feature1 = true
+"""
+        result = self.parser.parse_toml(content)
+
+        assert result["name"] == "myapp"
+        assert result["port"] == 8080
+        assert result["features"]["feature1"] is True
+
+    def test_parse_auto_detect_json(self):
+        """Test auto-detecting JSON format."""
+        content = '{"name": "myapp"}'
+        result = self.parser.parse(content)
+
+        assert isinstance(result, dict)
+        assert result["name"] == "myapp"
+
+    def test_parse_auto_detect_yaml(self):
+        """Test auto-detecting YAML format."""
+        content = "name: myapp"
+        result = self.parser.parse(content)
+
+        assert isinstance(result, dict)
+        assert result["name"] == "myapp"
+
+    def test_to_json(self):
+        """Test converting to JSON."""
+        data = {"name": "myapp", "port": 8080}
+        result = self.parser.to_json(data)
+
+        assert "myapp" in result
+        assert "8080" in result
+
+    def test_to_yaml(self):
+        """Test converting to YAML."""
+        data = {"name": "myapp", "port": 8080}
+        result = self.parser.to_yaml(data)
+
+        assert "myapp" in result
+        assert "8080" in result
+
+    def test_to_toml(self):
+        """Test converting to TOML."""
+        data = {"name": "myapp", "port": 8080}
+        result = self.parser.to_toml(data)
+
+        assert "myapp" in result
+        assert "8080" in result
+
+    def test_detect_format_from_path_json(self):
+        """Test detecting format from JSON file path."""
+        result = self.parser.detect_format_from_path("config.json")
+        assert result == "json"
+
+    def test_detect_format_from_path_yaml(self):
+        """Test detecting format from YAML file path."""
+        result = self.parser.detect_format_from_path("config.yaml")
+        assert result == "yaml"
+
+    def test_detect_format_from_path_yml(self):
+        """Test detecting format from YML file path."""
+        result = self.parser.detect_format_from_path("config.yml")
+        assert result == "yaml"
+
+    def test_detect_format_from_path_toml(self):
+        """Test detecting format from TOML file path."""
+        result = self.parser.detect_format_from_path("config.toml")
+        assert result == "toml"
+
+    def test_load_file_json(self):
+        """Test loading a JSON file."""
+        with tempfile.NamedTemporaryFile(
+            mode="w", suffix=".json", delete=False
+        ) as f:
+            json.dump({"name": "myapp", "port": 8080}, f)
+            temp_path = f.name
+
+        try:
+            result = self.parser.load_file(temp_path)
+
+            assert result["name"] == "myapp"
+            assert result["port"] == 8080
+        finally:
+            Path(temp_path).unlink()
+
+    def test_load_file_yaml(self):
+        """Test loading a YAML file."""
+        with tempfile.NamedTemporaryFile(
+            mode="w", suffix=".yaml", delete=False
+        ) as f:
+            f.write("name: myapp\nport: 8080")
+            temp_path = f.name
+
+        try:
+            result = self.parser.load_file(temp_path)
+
+            assert result["name"] == "myapp"
+            assert result["port"] == 8080
+        finally:
+            Path(temp_path).unlink()
+
+    def test_save_file(self):
+        """Test saving a config file."""
+        with tempfile.TemporaryDirectory() as tmpdir:
+            data = {"name": "myapp", "port": 8080}
+            self.parser.save_file(f"{tmpdir}/config.yaml", data)
+
+            assert Path(f"{tmpdir}/config.yaml").exists()
+
+            with open(f"{tmpdir}/config.yaml") as f:
+                content = f.read()
+
+            assert "myapp" in content
+            assert "8080" in content
+
+    def test_parse_invalid_json(self):
+        """Test that invalid JSON raises an error."""
+        content = '{"name": "myapp",'
+
+        with pytest.raises(ValueError, match="Invalid JSON"):
+            self.parser.parse_json(content)
+
+    def test_parse_invalid_yaml(self):
+        """Test that invalid YAML raises an error."""
+        content = "name: [invalid yaml"
+
+        with pytest.raises(ValueError, match="Invalid YAML"):
+            self.parser.parse_yaml(content)
+
+    def test_parse_nested_dict(self):
+        """Test parsing nested dictionaries."""
+        content = """
+database:
+  host: localhost
+  port: 5432
+  settings:
+    ssl: true
+    timeout: 30
+"""
+        result = self.parser.parse_yaml(content)
+
+        assert result["database"]["host"] == "localhost"
+        assert result["database"]["port"] == 5432
+        assert result["database"]["settings"]["ssl"] is True
+
+    def test_parse_with_list(self):
+        """Test parsing configurations with lists."""
+        content = """
+services:
+  - name: web
+    port: 80
+  - name: api
+    port: 8080
+features:
+  - feature1
+  - feature2
+"""
+        result = self.parser.parse_yaml(content)
+
+        assert len(result["services"]) == 2
+        assert result["services"][0]["name"] == "web"
+        assert len(result["features"]) == 2