Best Practices for Selecting XPath Locators in UI Automation
Check out this Xpath Validator utility where you can validate multiple Xpaths.
One of the most crucial aspects of UI testing with tools like Selenium is selecting reliable locators for web elements. XPath is a powerful and flexible way to locate elements but can also be prone to errors if not used carefully. Following best practices when writing XPath expressions ensures that your tests are stable, maintainable, and efficient.
Let’s break down the best practices for selecting XPath locators.
- Prefer Relative XPath Over Absolute XPath
Absolute XPath starts from the root of the document (/html/body/
) and follows a direct path to the target element. If the structure of the page changes even slightly, such as adding a new<div>
, your test will break because the entire path gets disrupted. - Use Unique Attributes to Locate Elements
Unique attributes likeid
orname
are less likely to change and provide an unambiguous way to identify an element. If theid
orname
of an element is available, it’s always preferable over other complex XPath expressions. - Avoid Using Positional Indexing (like [1], [2], etc.)
Indexing relies on the position of elements within their parent container, which can easily change. For example, adding a new element to the DOM can shift the position and break your test. - Use
contains()
Wisely
Whilecontains()
allows for flexibility, it can make your locator more fragile. It’s often better to locate elements using exact matches with unique attributes if possible. Moreover,contains()
can sometimes slow down performance when traversing large DOM trees. - Use
normalize-space()
to Handle Whitespace Issues
This ensures that any irregular whitespace around the text is ignored, making the XPath more flexible for locating elements. - Consider Performance: Use CSS Selectors Where Appropriate
While XPath is versatile, it’s generally slower than CSS selectors, especially when the DOM is large and complex. If your element can be located using a CSS selector, it’s usually better for performance. - Be Cautious with Dynamic Attributes
Some websites use dynamic attributes, such as randomly generatedid
orclass
names that change each time the page loads. Be careful not to rely on these attributes when writing your XPath expressions.
Avoid dynamic attributes like below.
//input[@id=’random12345'] - Combine Multiple Attributes for Precision
Sometimes, no single attribute is unique enough to identify an element. In such cases, you can combine multiple attributes to make your locator more precise.
Alternatively, Instead, look for stable attributes or parent elements with static properties, and use a relative path from there.
//button[@class='submit-btn' and @data-action='submit' and @type='submit']
9. Use Text() Wisely
The text()
function can be useful for finding elements with specific text content, but be cautious as text can change frequently.
Good (if the text is unlikely to change)
10. Avoid Using XPath Axes Unnecessarily
XPath axes like following-sibling
, preceding
, ancestor
, etc., can make your locators complex and slow. Use them sparingly and only when necessary.
11. Keep XPaths as Short and Simple as Possible
Shorter, simpler XPaths are generally faster and easier to maintain.
12. Document Complex XPaths
If you need to use a complex XPath, add a comment explaining why it’s necessary and what it’s selecting. This helps with future maintenance.
By following these best practices, your UI automation scripts will be more reliable, easier to maintain, and resilient to changes in the DOM structure.