diff --git a/testing/web-platform/meta/MANIFEST.json b/testing/web-platform/meta/MANIFEST.json
index 6aea24aecaa1..eb9884000246 100644
--- a/testing/web-platform/meta/MANIFEST.json
+++ b/testing/web-platform/meta/MANIFEST.json
@@ -298090,6 +298090,11 @@
      {}
     ]
    ],
+   "webdriver/tests/back/conftest.py": [
+    [
+     {}
+    ]
+   ],
    "webdriver/tests/close_window/__init__.py": [
     [
      {}
@@ -408620,6 +408625,14 @@
      {}
     ]
    ],
+   "webdriver/tests/back/user_prompts.py": [
+    [
+     "/webdriver/tests/back/user_prompts.py",
+     {
+      "timeout": "long"
+     }
+    ]
+   ],
    "webdriver/tests/close_window/close.py": [
     [
      "/webdriver/tests/close_window/close.py",
@@ -624138,7 +624151,15 @@
    "support"
   ],
   "webdriver/tests/back/back.py": [
-   "0df671f059b0b9064a6a8608163b46042524f7e7",
+   "ae4209c3f47af5e13c0851f73ad3d1f788b7ed56",
+   "wdspec"
+  ],
+  "webdriver/tests/back/conftest.py": [
+   "a15c7372ba9d459ddcc4b5cf4030eb32406b60cf",
+   "support"
+  ],
+  "webdriver/tests/back/user_prompts.py": [
+   "53944b4a302d2e1c5cde4e48ff451452d699f7f6",
    "wdspec"
   ],
   "webdriver/tests/close_window/__init__.py": [
diff --git a/testing/web-platform/tests/webdriver/tests/back/back.py b/testing/web-platform/tests/webdriver/tests/back/back.py
index bbb353697a45..0ecfccc193c6 100644
--- a/testing/web-platform/tests/webdriver/tests/back/back.py
+++ b/testing/web-platform/tests/webdriver/tests/back/back.py
@@ -1,5 +1,5 @@
 from tests.support.inline import inline
-from tests.support.asserts import assert_success
+from tests.support.asserts import assert_error, assert_success
 
 
 def back(session):
@@ -14,3 +14,99 @@ def test_null_response_value(session):
     response = back(session)
     value = assert_success(response)
     assert value is None
+
+
+def test_no_browsing_context(session, create_window):
+    new_handle = create_window()
+
+    session.window_handle = new_handle
+    session.close()
+    assert new_handle not in session.handles
+
+    response = back(session)
+    assert_error(response, "no such window")
+
+
+def test_no_browsing_history(session):
+    response = back(session)
+    assert_success(response)
+
+
+def test_data_urls(session):
+    test_pages = [
+        inline("<p id=1>"),
+        inline("<p id=2>"),
+    ]
+
+    for page in test_pages:
+        session.url = page
+    assert session.url == test_pages[1]
+
+    response = back(session)
+    assert_success(response)
+    assert session.url == test_pages[0]
+
+
+def test_dismissed_beforeunload(session):
+    url_beforeunload = inline("""
+      <input type="text">
+      <script>
+        window.addEventListener("beforeunload", function (event) {
+          event.preventDefault();
+        });
+      </script>
+    """)
+
+    session.url = inline("<div id=foo>")
+    session.url = url_beforeunload
+
+    element = session.find.css("input", all=False)
+    element.send_keys("bar")
+
+    response = back(session)
+    assert_success(response)
+
+    assert session.url != url_beforeunload
+
+
+def test_fragments(session, url):
+    test_pages = [
+        url("/common/blank.html"),
+        url("/common/blank.html#1234"),
+        url("/common/blank.html#5678"),
+    ]
+
+    for page in test_pages:
+        session.url = page
+    assert session.url == test_pages[2]
+
+    response = back(session)
+    assert_success(response)
+    assert session.url == test_pages[1]
+
+    response = back(session)
+    assert_success(response)
+    assert session.url == test_pages[0]
+
+
+def test_history_pushstate(session, url):
+    pushstate_page = inline("""
+      <script>
+        function pushState() {
+          history.pushState({foo: "bar"}, "", "#pushstate");
+        }
+      </script>
+      <a onclick="javascript:pushState();">click</a>
+    """)
+
+    session.url = pushstate_page
+    session.find.css("a", all=False).click()
+
+    assert session.url == "{}#pushstate".format(pushstate_page)
+    assert session.execute_script("return history.state;") == {"foo": "bar"}
+
+    response = back(session)
+    assert_success(response)
+
+    assert session.url == pushstate_page
+    assert session.execute_script("return history.state;") is None
diff --git a/testing/web-platform/tests/webdriver/tests/back/conftest.py b/testing/web-platform/tests/webdriver/tests/back/conftest.py
new file mode 100644
index 000000000000..d5fd320a696a
--- /dev/null
+++ b/testing/web-platform/tests/webdriver/tests/back/conftest.py
@@ -0,0 +1,19 @@
+import pytest
+
+from webdriver.error import NoSuchWindowException
+
+
+@pytest.fixture(name="session")
+def fixture_session(capabilities, session, create_window):
+    """Prevent re-using existent history by running the test in a new window."""
+    original_handle = session.window_handle
+    session.window_handle = create_window()
+
+    yield session
+
+    try:
+        session.close()
+    except NoSuchWindowException:
+        pass
+
+    session.window_handle = original_handle
diff --git a/testing/web-platform/tests/webdriver/tests/back/user_prompts.py b/testing/web-platform/tests/webdriver/tests/back/user_prompts.py
new file mode 100644
index 000000000000..0aefe46284f2
--- /dev/null
+++ b/testing/web-platform/tests/webdriver/tests/back/user_prompts.py
@@ -0,0 +1,68 @@
+# META: timeout=long
+
+import pytest
+
+from tests.support.asserts import assert_dialog_handled, assert_error, assert_success
+
+
+def back(session):
+    return session.transport.send(
+        "POST", "session/{session_id}/back".format(**vars(session)))
+
+
+@pytest.mark.capabilities({"unhandledPromptBehavior": "accept"})
+@pytest.mark.parametrize("dialog_type", ["alert", "confirm", "prompt"])
+def test_handle_prompt_accept(session, create_dialog, dialog_type):
+    create_dialog(dialog_type, text="dialog")
+
+    response = back(session)
+    assert_success(response)
+
+    assert_dialog_handled(session, expected_text="dialog")
+
+
+@pytest.mark.capabilities({"unhandledPromptBehavior": "accept and notify"})
+@pytest.mark.parametrize("dialog_type", ["alert", "confirm", "prompt"])
+def test_handle_prompt_accept_and_notify(session, create_dialog, dialog_type):
+    create_dialog(dialog_type, text="dialog")
+
+    response = back(session)
+    assert_error(response, "unexpected alert open")
+
+    assert_dialog_handled(session, expected_text="dialog")
+
+
+@pytest.mark.capabilities({"unhandledPromptBehavior": "dismiss"})
+@pytest.mark.parametrize("dialog_type", ["alert", "confirm", "prompt"])
+def test_handle_prompt_dismiss(session, create_dialog, dialog_type):
+    create_dialog(dialog_type, text="dialog")
+
+    response = back(session)
+    assert_success(response)
+
+    assert_dialog_handled(session, expected_text="dialog")
+
+
+@pytest.mark.capabilities({"unhandledPromptBehavior": "dismiss and notify"})
+@pytest.mark.parametrize("dialog_type", ["alert", "confirm", "prompt"])
+def test_handle_prompt_dissmiss_and_notify(session, create_dialog, dialog_type):
+    create_dialog(dialog_type, text="dialog")
+
+    response = back(session)
+    assert_error(response, "unexpected alert open")
+
+    assert_dialog_handled(session, expected_text="dialog")
+
+
+def test_handle_prompt_ignore():
+    """TODO"""
+
+
+@pytest.mark.parametrize("dialog_type", ["alert", "confirm", "prompt"])
+def test_handle_prompt_default(session, create_dialog, dialog_type):
+    create_dialog(dialog_type, text="dialog")
+
+    response = back(session)
+    assert_error(response, "unexpected alert open")
+
+    assert_dialog_handled(session, expected_text="dialog")