diff --git a/src/SeleniumLibrary/__init__.py b/src/SeleniumLibrary/__init__.py
index abe3c215..bb237dab 100644
--- a/src/SeleniumLibrary/__init__.py
+++ b/src/SeleniumLibrary/__init__.py
@@ -283,8 +283,8 @@ class SeleniumLibrary(DynamicCore):
 
     Some keywords accept arguments that are handled as Boolean values true or
     false. If such an argument is given as a string, it is considered false if
-    it is either empty or case-insensitively equal to ``false``, ``no`` or
-    ``none``. Other strings are considered true regardless their value, and
+    it is either empty or case-insensitively equal to ``false``, ``no``, ``off``,
+     ``0`` or ``none``. Other strings are considered true regardless their value, and
     other argument types are tested using same
     [https://docs.python.org/2/library/stdtypes.html#truth-value-testing|rules as in Python].
 
@@ -305,7 +305,8 @@ class SeleniumLibrary(DynamicCore):
     | `Set Screenshot Directory` | ${RESULTS} | persist=${NONE}  | # Python None is false.         |
 
     Note that prior to SeleniumLibrary 3.0, all non-empty strings, including
-    ``false``, ``no`` and ``none``, were considered true.
+    ``false``, ``no`` and ``none``, were considered true. Starting from
+    SeleniumLibrary 4.0, strings ``0`` and ``off`` are considered as false.
 
     = Thread support =
 
diff --git a/src/SeleniumLibrary/utils/types.py b/src/SeleniumLibrary/utils/types.py
index 47162e02..edae4c2c 100644
--- a/src/SeleniumLibrary/utils/types.py
+++ b/src/SeleniumLibrary/utils/types.py
@@ -16,15 +16,16 @@
 
 # Originally based on  Robot Framework 3.0.2 robot.utils.robottypes and
 # Can be removed when library minimum required Robot Framework
-# version is greater than 3.0.2. Then Robot Framework is_truthy should
-# also support string NONE as Python False.
+# version is greater than 3.0.4. Then Robot Framework is_truthy should
+# also support string NONE as Python False. Also string 0 is evaluated
+# as False in RF 3.1 but not in 3.0.4.
 from robot.utils import is_string
 from robot.utils import PY3
 
 
 def is_truthy(item):
     if is_string(item):
-        return item.upper() not in ('FALSE', 'NO', '', 'NONE')
+        return item.upper() not in ('FALSE', 'NO', '', 'NONE', '0', 'OFF')
     return bool(item)
 
 

Update SeleniumLibrary is_truthy and is_falsy to follow Robot Framework 3.1 
In Robot Framework `is_truthy` and `is_falsy` has changed between 3.0 and 3.1 version. In Robot Framewrok 3.1 string `0` is considered `False`, but in 3.0 string `0` is `True`. Same also applies to string `off`. Change SeleniumLibrary `is_truthy` and `is_falsy` to follow RF 3.1. 

Reference  #1304 
diff --git a/utest/test/keywords/test_cookie.py b/utest/test/keywords/test_cookie.py
index 27cfc83d..c85caaf9 100644
--- a/utest/test/keywords/test_cookie.py
+++ b/utest/test/keywords/test_cookie.py
@@ -33,7 +33,7 @@ class KeywordArgumentsCookieTest(unittest.TestCase):
                                secure=True)
         verify(self.driver, times=3).add_cookie(cookie)
         self.cookie.add_cookie('name', 'value', path='None', domain='None',
-                               secure='0')
+                               secure='1')
         verify(self.driver, times=4).add_cookie(cookie)
 
     def test_add_cookie_secure_false(self):
diff --git a/utest/test/utils/test_types.py b/utest/test/utils/test_types.py
index ddee7c66..50e79051 100644
--- a/utest/test/utils/test_types.py
+++ b/utest/test/utils/test_types.py
@@ -4,8 +4,8 @@ from SeleniumLibrary.utils import is_truthy, is_falsy, is_noney
 
 
 class IsTruthyFalsyNoneyTests(unittest.TestCase):
-    truthy = ['0', 'foo', ' ', 1, 2.3, True, [1], 'True', {'k': 'v'}]
-    falsy = [0, False, None, [], {}, (), u'', '', 'False', 'None']
+    truthy = ['foo', ' ', 1, 2.3, True, [1], 'True', {'k': 'v'}]
+    falsy = [0, False, None, [], {}, (), u'', '', 'False', 'None', '0', 'off']
 
     def test_is_truthy(self):
         for item in self.truthy:

pip install -e .[dev]
parse_log_pytest
requirements.txt
pytest pytest-cov pytest-xdist pytest-mock pytest-asyncio mockito
apt-get update apt-get install -y gcc
3.9
requirements.txt
pytest --no-header -rA --tb=line --color=no -p no:cacheprovider -W ignore::DeprecationWarning
attrs==25.3.0
certifi==2025.1.31
coverage==7.8.0
exceptiongroup==1.2.2
execnet==2.1.1
h11==0.14.0
idna==3.10
iniconfig==2.1.0
mockito==1.5.4
outcome==1.3.0.post0
packaging==24.2
pluggy==1.5.0
PySocks==1.7.1
pytest==8.3.5
pytest-asyncio==0.26.0
pytest-cov==6.0.0
pytest-mock==3.14.0
pytest-xdist==3.6.1
robotframework==7.2.2
-e git+https://github.com/robotframework/SeleniumLibrary.git@bcdd57a2f3bc06f32c666733e243f428abe51a42#egg=robotframework_seleniumlibrary
selenium==4.30.0
sniffio==1.3.1
sortedcontainers==2.4.0
tomli==2.2.1
trio==0.29.0
trio-websocket==0.12.2
typing_extensions==4.13.0
urllib3==2.3.0
websocket-client==1.8.0
wsproto==1.2.0

name: SeleniumLibrary
channels:
  - defaults
  - https://repo.anaconda.com/pkgs/main
  - https://repo.anaconda.com/pkgs/r
  - conda-forge
dependencies:
  - _libgcc_mutex=0.1=main
  - _openmp_mutex=5.1=1_gnu
  - ca-certificates=2025.2.25=h06a4308_0
  - ld_impl_linux-64=2.40=h12ee557_0
  - libffi=3.4.4=h6a678d5_1
  - libgcc-ng=11.2.0=h1234567_1
  - libgomp=11.2.0=h1234567_1
  - libstdcxx-ng=11.2.0=h1234567_1
  - ncurses=6.4=h6a678d5_0
  - openssl=3.0.16=h5eee18b_0
  - pip=25.0=py39h06a4308_0
  - python=3.9.21=he870216_1
  - readline=8.2=h5eee18b_0
  - setuptools=75.8.0=py39h06a4308_0
  - sqlite=3.45.3=h5eee18b_0
  - tk=8.6.14=h39e8969_0
  - tzdata=2025a=h04d1e81_0
  - wheel=0.45.1=py39h06a4308_0
  - xz=5.6.4=h5eee18b_1
  - zlib=1.2.13=h5eee18b_1
  - pip:
      - attrs==25.3.0
      - certifi==2025.1.31
      - coverage==7.8.0
      - exceptiongroup==1.2.2
      - execnet==2.1.1
      - h11==0.14.0
      - idna==3.10
      - iniconfig==2.1.0
      - mockito==1.5.4
      - outcome==1.3.0.post0
      - packaging==24.2
      - pluggy==1.5.0
      - pysocks==1.7.1
      - pytest==8.3.5
      - pytest-asyncio==0.26.0
      - pytest-cov==6.0.0
      - pytest-mock==3.14.0
      - pytest-xdist==3.6.1
      - robotframework==7.2.2
      - selenium==4.30.0
      - sniffio==1.3.1
      - sortedcontainers==2.4.0
      - tomli==2.2.1
      - trio==0.29.0
      - trio-websocket==0.12.2
      - typing-extensions==4.13.0
      - urllib3==2.3.0
      - websocket-client==1.8.0
      - wsproto==1.2.0
prefix: /opt/conda/envs/SeleniumLibrary

utest/test/utils/test_types.py::IsTruthyFalsyNoneyTests::test_is_falsy utest/test/utils/test_types.py::IsTruthyFalsyNoneyTests::test_is_truthy
utest/test/keywords/test_cookie.py::KeywordArgumentsCookieTest::test_add_cookie_default utest/test/keywords/test_cookie.py::KeywordArgumentsCookieTest::test_add_cookie_domain_false utest/test/keywords/test_cookie.py::KeywordArgumentsCookieTest::test_add_cookie_domain_true utest/test/keywords/test_cookie.py::KeywordArgumentsCookieTest::test_add_cookie_path_false utest/test/keywords/test_cookie.py::KeywordArgumentsCookieTest::test_add_cookie_path_true utest/test/keywords/test_cookie.py::KeywordArgumentsCookieTest::test_add_cookie_secure_false utest/test/keywords/test_cookie.py::KeywordArgumentsCookieTest::test_add_cookie_secure_true utest/test/utils/test_types.py::IsTruthyFalsyNoneyTests::test_is_noney
src/SeleniumLibrary/__init__.py src/SeleniumLibrary/utils/types.py
src/SeleniumLibrary/__init__.py src/SeleniumLibrary/utils/types.py