diff --git a/tests/test_type_inference.py b/tests/test_type_inference.py
new file mode 100644
index 0000000..9026284
--- /dev/null
+++ b/tests/test_type_inference.py
@@ -0,0 +1,161 @@
+"""Tests for JSON type inference."""
+import pytest
+from json_to_openapi.analyzer import JsonAnalyzer, TypeInfo
+
+
+class TestJsonAnalyzer:
+    """Test cases for JsonAnalyzer."""
+
+    def test_analyze_string(self):
+        analyzer = JsonAnalyzer()
+        result = analyzer.analyze("hello")
+        assert result.type_name == "string"
+
+    def test_analyze_integer(self):
+        analyzer = JsonAnalyzer()
+        result = analyzer.analyze(42)
+        assert result.type_name == "integer"
+
+    def test_analyze_float(self):
+        analyzer = JsonAnalyzer()
+        result = analyzer.analyze(3.14)
+        assert result.type_name == "number"
+
+    def test_analyze_boolean_true(self):
+        analyzer = JsonAnalyzer()
+        result = analyzer.analyze(True)
+        assert result.type_name == "boolean"
+
+    def test_analyze_boolean_false(self):
+        analyzer = JsonAnalyzer()
+        result = analyzer.analyze(False)
+        assert result.type_name == "boolean"
+
+    def test_analyze_null(self):
+        analyzer = JsonAnalyzer()
+        result = analyzer.analyze(None)
+        assert result.type_name == "null"
+
+    def test_analyze_empty_array(self):
+        analyzer = JsonAnalyzer()
+        result = analyzer.analyze([])
+        assert result.type_name == "array"
+
+    def test_analyze_empty_object(self):
+        analyzer = JsonAnalyzer()
+        result = analyzer.analyze({})
+        assert result.type_name == "object"
+
+    def test_analyze_string_format_date(self):
+        analyzer = JsonAnalyzer()
+        result = analyzer.analyze("2024-01-15")
+        assert result.type_name == "string"
+        assert result.format == "date"
+
+    def test_analyze_string_format_datetime(self):
+        analyzer = JsonAnalyzer()
+        result = analyzer.analyze("2024-01-15T10:30:00Z")
+        assert result.type_name == "string"
+        assert result.format == "date-time"
+
+    def test_analyze_string_format_email(self):
+        analyzer = JsonAnalyzer()
+        result = analyzer.analyze("user@example.com")
+        assert result.type_name == "string"
+        assert result.format == "email"
+
+    def test_analyze_string_format_uuid(self):
+        analyzer = JsonAnalyzer()
+        result = analyzer.analyze("550e8400-e29b-41d4-a716-446655440000")
+        assert result.type_name == "string"
+        assert result.format == "uuid"
+
+    def test_analyze_object_with_properties(self):
+        analyzer = JsonAnalyzer()
+        result = analyzer.analyze({"name": "John", "age": 30})
+        assert result.type_name == "object"
+        assert result.properties is not None
+        assert "name" in result.properties
+        assert "age" in result.properties
+        assert result.properties["name"].type_name == "string"
+        assert result.properties["age"].type_name == "integer"
+
+    def test_analyze_nested_object(self):
+        analyzer = JsonAnalyzer()
+        result = analyzer.analyze({"user": {"address": {"city": "Boston"}}})
+        assert result.type_name == "object"
+        assert result.properties["user"].type_name == "object"
+        assert result.properties["user"].properties["address"].type_name == "object"
+        assert result.properties["user"].properties["address"].properties["city"].type_name == "string"
+
+    def test_analyze_array_of_strings(self):
+        analyzer = JsonAnalyzer()
+        result = analyzer.analyze(["a", "b", "c"])
+        assert result.type_name == "array"
+        assert result.items is not None
+        assert result.items.type_name == "string"
+
+    def test_analyze_array_of_integers(self):
+        analyzer = JsonAnalyzer()
+        result = analyzer.analyze([1, 2, 3])
+        assert result.type_name == "array"
+        assert result.items is not None
+        assert result.items.type_name == "integer"
+
+    def test_analyze_array_of_objects(self):
+        analyzer = JsonAnalyzer()
+        result = analyzer.analyze([{"id": 1}, {"id": 2}])
+        assert result.type_name == "array"
+        assert result.items is not None
+        assert result.items.type_name == "object"
+        assert result.items.properties is not None
+        assert "id" in result.items.properties
+
+    def test_analyze_mixed_array(self):
+        analyzer = JsonAnalyzer()
+        result = analyzer.analyze(["text", 123, True])
+        assert result.type_name == "array"
+
+    def test_analyze_large_integer(self):
+        analyzer = JsonAnalyzer()
+        result = analyzer.analyze(9999999999999)
+        assert result.type_name == "integer"
+        assert result.format == "int64"
+
+    def test_analyze_uri_format(self):
+        analyzer = JsonAnalyzer()
+        result = analyzer.analyze("https://example.com/api")
+        assert result.type_name == "string"
+        assert result.format == "uri"
+
+    def test_max_depth_prevents_infinite_recursion(self):
+        analyzer = JsonAnalyzer(max_depth=3)
+        data = {"level1": {"level2": {"level3": {"level4": {"value": 1}}}}}
+        result = analyzer.analyze(data)
+        assert result.type_name == "object"
+
+
+class TestTypeInfo:
+    """Test cases for TypeInfo dataclass."""
+
+    def test_type_info_creation(self):
+        type_info = TypeInfo(type_name="string")
+        assert type_info.type_name == "string"
+        assert type_info.format is None
+        assert type_info.properties is None
+        assert type_info.items is None
+        assert type_info.enum_values is None
+        assert type_info.nullable is False
+
+    def test_type_info_with_all_fields(self):
+        type_info = TypeInfo(
+            type_name="object",
+            format=None,
+            properties={"key": TypeInfo(type_name="string")},
+            items=None,
+            enum_values=["a", "b"],
+            nullable=True
+        )
+        assert type_info.type_name == "object"
+        assert type_info.nullable is True
+        assert len(type_info.enum_values) == 2