diff --git a/integration_tests/test_codemod_urls.py b/integration_tests/test_codemod_urls.py
new file mode 100644
index 00000000..959a5c60
--- /dev/null
+++ b/integration_tests/test_codemod_urls.py
@@ -0,0 +1,54 @@
+import asyncio
+
+import httpx
+import pytest
+
+from codemodder.registry import load_registered_codemods
+
+registry = load_registered_codemods()
+
+
+async def visit_url(client, url):
+    try:
+        response = await client.get(url)
+        return url, response.status_code
+    except httpx.RequestError:
+        return url, None
+
+
+@pytest.mark.asyncio
+async def check_accessible_urls(urls):
+    async with httpx.AsyncClient() as client:
+        tasks = [visit_url(client, url) for url in urls]
+        results = await asyncio.gather(*tasks)
+
+    if failures := [
+        (url, status) for url, status in results if status not in (200, 301, 302)
+    ]:
+        if failures:
+            failure_messages = [f"{url}: status={status}" for url, status in failures]
+            pytest.fail(
+                "Update the following URLs because they are not accessible:\n{}".format(
+                    "\n".join(failure_messages)
+                )
+            )
+
+
+@pytest.mark.asyncio
+async def test_codemod_reference_urls():
+    urls = [
+        ref.url for codemod in registry.codemods for ref in codemod._metadata.references
+    ]
+    await check_accessible_urls(urls)
+
+
+@pytest.mark.asyncio
+async def test_tool_rules_urls():
+    urls = [
+        rule.url
+        for codemod in registry.codemods
+        if (tool := codemod._metadata.tool)
+        for rule in tool.rules
+        if rule.url
+    ]
+    await check_accessible_urls(urls)
diff --git a/pyproject.toml b/pyproject.toml
index 3bde5351..a16c9c9a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -52,6 +52,7 @@ test = [
     "coverage>=7.3,<7.6",
     "coverage-threshold~=0.4",
     "Flask<4",
+    "httpx~=0.27",
     "Jinja2~=3.1.2",
     "jsonschema~=4.22.0",
     "lxml>=4.9.3,<5.3.0",
@@ -60,6 +61,7 @@ test = [
     "pre-commit<4",
     "Pyjwt~=2.8.0",
     "pytest>=8.2,<9",
+    "pytest-asyncio~=0.23",
     "pytest-cov>=4.1,<5.1",
     "pytest-mock>=3.12,<3.15",
     "pytest-randomly==3.*",