Stale element reference
The stale element reference error is a WebDriver error that occurs because the referenced web element is no longer attached to the DOM.
Every DOM element is represented in WebDriver by a unique identifying reference, known as a web element. The web element reference is a UUID used to execute commands targeting specific elements, such as getting an element's tag name and retrieving a property off an element.
When an element is no longer attached to the DOM, i.e. it has been removed from the document or the document has changed, it is said to be stale. Staleness occurs for example when you have a web element reference and the document it was retrieved from navigates.
Examples
Document navigation
Upon navigation, all web element references to the previous document will be discarded along with the document. This will cause any subsequent interaction with the web element to fail with the stale element reference error:
python
import urllib
from selenium import webdriver
from selenium.common import exceptions
def inline(doc):
return "data:text/html;charset=utf-8,{}".format(urllib.quote(doc))
session = webdriver.Firefox()
session.get(inline("<strong>foo</strong>"))
foo = session.find_element_by_css_selector("strong")
session.get(inline("<i>bar</i>"))
try:
foo.tag_name
except exceptions.StaleElementReferenceException as e:
print(e)
Output:
StaleElementReferenceException: The element reference of e75a1764-ff73-40fa-93c1-08cb90394b65 is stale either the element is no longer attached to the DOM, it is not in the current frame context, or the document has been refreshed
Node removal
When a document node is removed from the DOM, its web element reference will be invalidated. This will also cause any subsequent interaction with the web element to fail with the stale element reference error:
python
import urllib
from selenium import webdriver
from selenium.common import exceptions
def inline(doc):
return "data:text/html;charset=utf-8,{}".format(urllib.quote(doc))
session = webdriver.Firefox()
session.get(inline("<button>foo</button>"))
button = session.find_element_by_css_selector("button")
session.execute_script("""
let [button] = arguments;
button.remove();
""", script_args=(button,))
try:
button.click()
except exceptions.StaleElementReferenceException as e:
print(e)
Output:
StaleElementReferenceException: The element reference of e75a1764-ff73-40fa-93c1-08cb90394b65 is stale either the element is no longer attached to the DOM, it is not in the current frame context, or the document has been refreshed
See also
- WebElement
- Associated commands: