+91 7387620624

get_css_value()

Introduction

The get_css_value() method is one of Selenium’s WebElement methods used to retrieve the computed CSS property values of a web element. It allows automation engineers to validate the visual appearance and styling of web applications during UI automation testing.

Modern web applications rely heavily on CSS for defining layouts, colors, fonts, dimensions, visibility, and responsiveness. The get_css_value() method enables Selenium to verify whether an element is rendered correctly by retrieving properties such as display, color, font-size, background-color, margin, padding, and many others.

In this tutorial, you’ll learn what get_css_value() is, why it is used, its syntax, practical examples, real-world use cases, common mistakes, and best practices.

What is get_css_value()?

The get_css_value() method returns the computed value of a CSS property associated with a web element.

Selenium retrieves the final CSS value after all stylesheets, browser defaults, and CSS rules have been applied to the element.

For example, consider the following HTML:

<button>
    Login
</button>

with the following CSS:

button{
    display:inline-block;
    color:white;
}

Selenium can retrieve these CSS property values using:

element.value_of_css_property(
    "property_name"
)

The get_css_value() method is commonly used for retrieving:

  • display

  • color

  • background-color

  • font-size

  • width

  • height

  • margin

  • padding

  • border properties

  • visibility

Why Use get_css_value()?

The get_css_value() method is useful because it:

  • Retrieves computed CSS property values.

  • Supports UI validation.

  • Improves automation reliability.

  • Helps validate application styling.

  • Produces readable automation scripts.

  • Is widely used in professional automation frameworks.

Syntax

element.value_of_css_property(
    "property_name"
)

Where:

  • element → Previously located WebElement.

  • "property_name" → Name of the CSS property.

  • value_of_css_property() → Returns the computed CSS value.

Note: Although this topic is commonly referred to as get_css_value(), Selenium’s Python implementation uses the value_of_css_property() method.

Example

The Selenium practice website contains a Login button. Selenium retrieves the computed value of its display property and validates that it is rendered as an inline-block element.

The Selenium code is:

from selenium import webdriver
from selenium.webdriver.common.by import By


# Topic: 17. Retrieving Element Information - get_css_value()
# Practice site: https://the-internet.herokuapp.com/login
# Run: pytest -s 17_examples/test_05_get_css_value.py
#
# get_css_value() returns the computed CSS property value for an element.


def test_get_css_value():
    driver = webdriver.Chrome()

    try:
        driver.get(
            "https://the-internet.herokuapp.com/login"
        )

        submit = driver.find_element(
            By.CSS_SELECTOR,
            "button[type='submit']"
        )

        display = submit.value_of_css_property(
            "display"
        )

        assert display == "inline-block"

    finally:
        driver.quit()

Output

The Login button's
display property is
retrieved successfully
and confirms that the
element is rendered as
an inline-block element.

Understanding the Code

Import the By Class

from selenium.webdriver.common.by import By

Imports Selenium’s locator strategies.

Open the Login Page

driver.get(
    "https://the-internet.herokuapp.com/login"
)

Launches the Selenium practice website.

Locate the Login Button

driver.find_element(
    By.CSS_SELECTOR,
    "button[type='submit']"
)

Locates the Login button displayed on the webpage.

Retrieve the CSS Property

submit.value_of_css_property(
    "display"
)

Returns:

inline-block

which represents the button’s computed CSS value.

Validate the Result

assert display == (
    "inline-block"
)

Verifies that Selenium successfully retrieves the expected CSS property value.

How get_css_value() Works

            Python Script
                   │
                   ▼
            Locate Web Element
                   │
                   ▼
      value_of_css_property()
                   │
                   ▼
           Read CSS Property
                   │
                   ▼
         Compute Final Value
                   │
                   ▼
             Compare Values
                   │
                   ▼
             Perform Validation

Practical Example

Suppose you’re automating an E-Commerce website.

A disabled Checkout button should appear as:

Gray Background
      │
      ▼
Disabled Appearance
      │
      ▼
Not Clickable

Selenium can validate its styling using:

button.value_of_css_property(
    "background-color"
)

and:

button.value_of_css_property(
    "display"
)

This significantly improves UI validation during automation testing.

Automation Testing Example

Consider an online banking application.

Automation engineers frequently validate:

  • Button colors.

  • Font sizes.

  • Visibility properties.

  • Disabled states.

  • Responsive layouts.

  • Success messages.

  • Error message styling.

  • Navigation menus.

Professional automation frameworks extensively use CSS property validation during UI regression testing.

Real-World Example

Automation engineers frequently use get_css_value() while automating:

  • Banking applications.

  • E-Commerce websites.

  • Healthcare portals.

  • CRM systems.

  • ERP applications.

  • SaaS products.

  • Enterprise web applications.

  • Registration forms.

  • Dynamic dashboards.

CSS validation has become increasingly important because modern applications rely heavily on sophisticated user interfaces and responsive designs.

Advantages of get_css_value()

  • Retrieves computed CSS property values.

  • Improves UI validation.

  • Produces maintainable automation scripts.

  • Supports responsive design testing.

  • Works across browsers.

  • Extensively used in professional automation frameworks.

Commonly Retrieved CSS Properties

Some frequently validated CSS properties include:

display
color
background-color
font-size
width
height
margin
padding
visibility
border
opacity
text-align

These properties are commonly validated during Selenium automation testing.

Common Mistakes Beginners Make

Confusing HTML Attributes with CSS Properties

Incorrect

element.get_attribute(
    "display"
)

Correct

element.value_of_css_property(
    "display"
)

HTML attributes and CSS properties are different concepts and should not be used interchangeably.

Using Incorrect CSS Property Names

Incorrect

element.value_of_css_property(
    "fontsize"
)

Correct

element.value_of_css_property(
    "font-size"
)

Always verify CSS property names using browser Developer Tools.

Ignoring Browser Differences

Some CSS properties may return values in different formats across browsers.

For example:

rgb(255, 255, 255)

may be returned instead of:

white

Always validate the actual values returned by Selenium during cross-browser testing.

Best Practices

  • Use value_of_css_property() when validating UI styling.

  • Verify CSS property names using browser Developer Tools.

  • Validate computed CSS values whenever appropriate.

  • Use synchronization techniques for dynamically styled elements.

  • Keep assertions simple and readable.

  • Consider browser-specific CSS differences during validation.

Conclusion

The get_css_value() functionality provided through Selenium’s value_of_css_property() method plays an important role in validating modern user interfaces during automation testing. It allows automation engineers to verify styling, responsiveness, and visual behavior across multiple browsers and environments.

Understanding how and when to validate CSS properties correctly is essential for building scalable, reliable, and maintainable Selenium automation frameworks.

Frequently Asked Questions (FAQs)

What is get_css_value() in Selenium?

It refers to retrieving the computed CSS property value of a web element.

What is the syntax in Selenium Python?

element.value_of_css_property(
    "property_name"
)

Can I validate colors using get_css_value()?

Yes.

You can validate:

  • color

  • background-color

  • border-color

  • opacity

  • font-size

  • display

  • and many other CSS properties.

Is get_css_value() available as a method in Selenium Python?

No.

Selenium Python uses:

value_of_css_property()

to retrieve computed CSS property values.

Why is CSS validation important?

CSS validation helps ensure that:

  • UI elements are rendered correctly.

  • Responsive layouts behave as expected.

  • Buttons and messages display appropriate styling.

  • User interactions are visually consistent across browsers.

Key Takeaways

  • get_css_value() retrieves computed CSS property values in Selenium Python through value_of_css_property().

  • It is extensively used for UI and styling validation.

  • Commonly validated properties include display, color, font-size, width, and visibility.

  • Always verify CSS property names before performing assertions.

  • Consider browser-specific differences during cross-browser testing.

  • CSS property validation is an important part of professional Selenium automation frameworks.