Understanding Following-Sibling XPath in Selenium

Overview of XPath Axes in Selenium

XPath axes describe the direction or relationship between a reference element (context node) and other elements in the DOM. They allow Selenium to navigate the DOM tree systematically and locate elements based on structural relationships rather than only attributes or text.

XPath axes can traverse in multiple directions:

• Child Axis: Selects direct children of the context node. For example, parent/child selects immediate children. Useful when elements are nested inside a container.
• Parent Axis: Selects the parent of the current node. For example, child/parent::* identifies the container element. Useful to move upward when only a child element is known.
• Ancestor Axis: Selects all ancestor nodes, including parent, grandparent, and higher. For example, element/ancestor::div retrieves all enclosing <div> elements.
• Descendant Axis: Selects all descendants of the current node, including children, grandchildren, and deeper levels. For example, container/descendant::button selects every button within the container.
• Following-Sibling Axis: Selects all siblings after the current node. For example, label/following-sibling::input locates the input next to a label. This is especially useful for forms or tables where elements are ordered sequentially.
• Preceding-Sibling Axis: Selects all siblings before the current node. For example, input/preceding-sibling::label finds the label associated with an input field.

Understanding Following-Sibling XPath

The following-sibling axis in XPath selects all sibling elements that appear after a reference element in the DOM. It is particularly useful when elements do not have unique identifiers but maintain a consistent order relative to other elements. This axis allows precise targeting without relying solely on classes, IDs, or text values.

Syntax Rules for Following-Sibling XPath

Following-sibling XPath uses the format:

reference_element/following-sibling::tag_name

• reference_element is the XPath of the element you are referencing.
• tag_name specifies the type of sibling element to select.
• Indexes can be added to select a specific sibling.

For example, //label[text()='Username']/following-sibling::input[1] selects the first input element immediately after the label with text Username.

Applying Following-Sibling XPath to Locate Elements

Following-sibling XPath can target elements based on text, partial matches, or attributes. Below are common approaches:

1. Selecting Elements by Exact Text

To locate an element that comes immediately after a label with a known text, use the following-sibling axis with the exact text of the reference element.

//label[text()='Password']/following-sibling::input

This selects the input field that directly follows the label containing Password.

2. Using contains(text()) for Partial Matches

When the reference label may have dynamic text or partial content, the contains() function can be used to match part of the text.

//label[contains(text(),'User')]/following-sibling::input

This selects the input field that comes immediately after a label containing the word User.

3. Targeting Elements via Attributes

If the elements do not have unique text but have consistent attributes, you can use the following-sibling axis with attribute conditions.

//div[@class='form-group']/following-sibling::div[@class='form-group']

This selects the next sibling div element with the class form-group.

Preceding-Sibling vs Following-Sibling XPath Axes

The following-sibling axis selects all siblings that appear after a reference element. It is useful when the target element consistently comes after a known element in the DOM.

For example, to select an input that comes immediately after a label:

//label[text()='Email']/following-sibling::input

This selects the input field immediately after the label with text Email.

The preceding-sibling axis selects all siblings that appear before a reference element. It is helpful when the target element appears earlier in the DOM relative to a known element.

For example, to select a label that comes immediately before an input:

//input[@id='email']/preceding-sibling::label

This selects the label that is positioned just before the input with ID email.

Techniques for Writing Reliable Following-Sibling XPath

Writing stable following-sibling XPath requires understanding both the DOM structure and the behavior of elements on the page. Unreliable XPath can break when elements move or page content changes. 

Below are key techniques to make following-sibling XPath robust.

1. Leveraging Unique Identifiers

When possible, start from an element with a unique ID, text, or attribute. This ensures the reference node is stable.

//label[@id='username']/following-sibling::input

This selects the input field after a label with a unique ID username.

2. Using Indexes Judiciously

Indexes can specify which sibling to select but should be used carefully because DOM changes can shift positions.

//label[text()='Option']/following-sibling::input[2]

This selects the second input after the label with text Option.

3. Combining with Other Attributes

Adding attribute conditions increases precision and reduces dependency on order alone.

//label[text()='Password']/following-sibling::input[@type='password']

This selects the input with type password after the label Password.

4. Minimizing Performance Overhead

Avoid overly broad XPath that search large DOM sections. Limit the search scope by starting from a specific container or parent element.

//div[@class='login-form']//label[text()='Email']/following-sibling::input

This selects the input field after the label Email within a specific div container, reducing DOM traversal.

Common Issues When Using Following-Sibling XPath

Following-sibling XPath are effective but can encounter specific challenges that may break tests. Understanding these issues helps create more reliable locators.

• Complex Hierarchies: Siblings nested within multiple containers can make simple following-sibling XPath fail. DOM structure must be considered when writing XPath.
• Performance Impact on Large DOMs: Searching across the entire page can slow down tests. Restricting the search to a parent container improves performance.
• Sibling Indexing Errors: Using indexes without verifying the DOM can select the wrong element if siblings are added or removed dynamically.
• Hidden or Off-Screen Siblings: Elements hidden with CSS or not visible on screen can still be selected, causing interactions like typing or clicking to fail.
• Changes in Element Order: Dynamic pages may reorder siblings, breaking XPath that rely only on sequence. Combining attributes with the following-sibling axis increases stability.

Why Test XPath on Real Devices?

Testing XPath on real devices ensures that locators work reliably across different environments and screen sizes. Even correct XPath can fail if the page layout or rendering differs on actual devices.

• Variations in Rendering: Elements may shift positions or be nested differently on mobile versus desktop, affecting following-sibling XPath.
• Dynamic Content: Real devices can expose dynamic changes such as delayed element rendering or lazy-loaded components that are not visible in emulators.
• Browser-Specific Behavior: Differences in browser engines may affect how the DOM is interpreted, impacting sibling relationships.
• Scrolling and Visibility Issues: Elements off-screen may require scrolling to interact with, which can break tests if not handled correctly.
• Accurate Validation: Testing on real devices confirms that interactions like clicks, typing, or selection work as intended in actual user environments.

To address these challenges, BrowserStack provides access to a wide range of real devices and browsers in the cloud. Testers can validate following-sibling XPath in authentic environments, detect layout or rendering issues, and ensure that scripts perform consistently without managing physical hardware.

Conclusion

Following-sibling XPath in Selenium locates an element that comes after a specific sibling. Use exact text to select a precise element, contains() to handle partial matches, and attributes to target elements when order changes. This ensures input fields, buttons, and other controls are consistently identified even on dynamic pages.

BrowserStack provides a cloud-based platform for running Selenium tests on a wide range of real devices and browsers. This allows testers to validate following-sibling XPath in real-world conditions, identify rendering issues, and ensure interactions like clicks and typing behave as expected without managing physical devices.