diff --git a/tests/analyzer_constants.py b/tests/analyzer_constants.py
index 8be4d89..ab650a1 100644
--- a/tests/analyzer_constants.py
+++ b/tests/analyzer_constants.py
@@ -1,14 +1,49 @@
 import unittest
 
 import onlinejudge_template.analyzer.constants as analyzer
-from onlinejudge_template.network import download_html
+from onlinejudge_template.network import download_html, download_sample_cases
 from onlinejudge_template.types import *
 
 
+class TestConstantsDetectorAtCoder(unittest.TestCase):
+    """TestConstantsDetectorAtCoder is a class for unit tests about the constants detection of AtCoder (with network access).
+    """
+    def test_agc043_c(self) -> None:
+        """In the statement, `,` are used as `998,244,353`.
+        """
+        url = 'https://atcoder.jp/contests/agc043/tasks/agc043_c'
+        expected = {
+            "MOD": ConstantDecl(name="MOD", value="998244353", type=VarType.ValueInt),
+        }
+
+        html = download_html(url)
+        self.assertEqual(analyzer.list_constants_from_html(html), expected)
+
+
+class TestConstantsDetectorCodeforces(unittest.TestCase):
+    """TestConstantsDetectorCodeforces is a class for unit tests about the constants detection of Codeforces (with network access).
+    """
+    def test_1395_a(self) -> None:
+        """The answer is `Yes` or `No`.
+        """
+
+        url = 'https://codeforces.com/contest/1395/problem/A'
+        expected = {
+            "YES": ConstantDecl(name="YES", value="Yes", type=VarType.String),
+            "NO": ConstantDecl(name="NO", value="No", type=VarType.String),
+        }
+
+        sample_cases = download_sample_cases(url)
+        self.assertEqual(analyzer.list_constants_from_sample_cases(sample_cases), expected)
+
+
 class TestConstantsDetectorYukicoder(unittest.TestCase):
     """TestConstantsDetectorYukicoder is a class for unit tests about the constants detection of yukicoder (with network access).
     """
     def test_no_1039(self) -> None:
+        """In the statement, specified as 「$\bmod 10^9+7$で答えてください。」
+        """
+
         url = 'https://yukicoder.me/problems/no/1039'
         expected = {
             "MOD": ConstantDecl(name="MOD", value="1000000007", type=VarType.ValueInt),
@@ -25,3 +60,16 @@ def test_no_1073(self) -> None:
 
         html = download_html(url)
         self.assertEqual(analyzer.list_constants_from_html(html), expected)
+
+
+class TestConstantsDetectorTopcoder(unittest.TestCase):
+    """TestConstantsDetectorTopcoder is a class for unit tests about the constants detection of Topcoder (with network access).
+    """
+    def test_apple_trees(self) -> None:
+        url = 'https://community.topcoder.com/stat?c=problem_statement&pm=11213'
+        expected = {
+            "MOD": ConstantDecl(name="MOD", value="1000000007", type=VarType.ValueInt),
+        }
+
+        html = download_html(url)
+        self.assertEqual(analyzer.list_constants_from_html(html), expected)