Cross-Browser Testing with Selenium



What Is Cross-Browser Testing?

Cross-browser testing is a type of functional testing used to ensure that web sites and web applications are compatible with various browsers. Cross-browser testing ensures that a site works as expected across popular browsers, allowing more people to access and use it regardless of their device, operating system, or resolution.

Cross-browser testing is critical for ensuring that software development teams provide their customers with flawless user experiences through cross-browser compatibility. Some of the differences discovered in different browsers include image orientation, user input positioning and validation, JavaScript implementation, font size, and page alignment. In addition, some browsers are incompatible with certain operating systems. Cross-browser testing allows software testers to spot and address such issues, thereby improving the user experience.

Getting started with cross-browser testing can be costly and difficult, especially given the various browsers, operating systems, and device combinations that you’ll need to test. While there are cloud-based cross-browser testing platforms, you can use Selenium and Python to create an internal testing grid. Continue reading to learn how to perform cross-browser testing with Selenium and Python.

What Is Selenium?

Selenium is a free open source software tool for automated cross-browser testing. It can validate the interoperability of websites and web applications across many platforms and browsers. You can create test scripts using Selenium with a single interface and a programming language like C#, Python, Node, or Java.

Why Use Selenium for Cross-Browser Testing?

Selenium is a well-known framework for automated cross-browser testing. By automating web app tests with Selenium, developers can test web apps across different operating systems and browser configurations. This ensures that every user has the same experience, regardless of their OS or browser version. When using Selenium for cross-browser testing, you can automate your tests and take advantage of a wide range of tools and possibilities. Due to its adaptability, it can simulate various test scenarios and use cases.

Selenium is also a good choice for cross-browser testing because it comes as a software suite with different options, including:

  • Selenium WebDriver, which is a set of browser-operating bindings for various languages. It offers an interface where many methods can be declared and applied to end-to-end testing.
  • Selenium IDE, which is an add-on that makes it easy to record and replay script interactions with browsers.
  • Selenium Grid, which is a software program suite designed to run many test cases against a wide range of browsers, operating systems, and hardware simultaneously. This facilitates testing and scales up test suites as they expand.

Benefits of Cross-Browser Testing

HTML, CSS, and JavaScript are rendered differently on websites and apps despite the fact that browser vendors follow Open Web Standards. For instance, Safari uses WebKit, whereas Firefox uses Gecko and Chrome and Microsoft Edge uses Blink. As a result, many browsers display the same site differently.

Prior to the introduction of a product, web developers and testers are responsible for abstracting browser differences through cross-browser testing. Cross-browser testing enables the speedy identification of browser-specific incompatibility issues. It makes sure that a substantial section of your application’s audience won’t be alienated because of their operating system or browser.

Other benefits of cross-browser testing include:

  • It ensures concurrent test execution results, which aids scalability.
  • It ensures that problems are discovered and fixed earlier, saving time and money.
  • When performed automatically, cross-browser testing extends the test coverage provided by concurrent execution across a variety of browsers, devices, and operating systems.
  • It improves the consumer experience by ensuring consistency in usability – regardless of their operating system and browser combination.

Automated vs. Manual Cross-Browser Testing with Selenium

To begin cross-browser testing, decide how much of the process will be automated and how much will be done manually. A human tester performs manual cross-browser testing on websites and mobile applications without the assistance of automated tools or scripts. This allows manual testers to examine aspects of the software that test scripts frequently overlook, such as design, usability, and feel. One disadvantage of manual cross-browser testing is that it takes a long time due to the amount of manual labor involved.

In contrast to manual testing, automated cross-browser testing is quicker and more practical because test scripts are created and run automatically using technologies like Selenium, which compares the outcomes to what was expected. As a result, teams can ship code more quickly and shorten their release cycles. In this post, we’ll concentrate on utilizing Python and Selenium to perform automated cross-browser testing.

Getting Started with Cross-Browser Testing Using Selenium and Python

We’ll show you how to perform cross-browser testing in two stages:

  1. Writing the test script using Python code.
  2. Running the tests on Sauce Labs.
I. Writing the Test Script Using Python Code

In order to write the Python test script, you must meet certain prerequisites. This includes installing the following:

  • Python 3: Download and set up Python 3 on your operating system.
  • A code editor: Install a code editor on your computer (ideally Visual Studio).
  • Selenium’s WebDriver for Python: Run pip3 install selenium in your terminal to install the Selenium WebDriver.

A browser driver proxy: Install the most recent browser driver that works with your OS and browser version. You can either hard code the location of the browser driver or set up the environment path using driver management software. For the purposes of this tutorial, we’ll import it straight from the WebDriver, as demonstrated below:

from selenium import webdriver
from import Service as ChromeService
from selenium.webdriver.edge.service import Service as EdgeService
from selenium.webdriver.firefox.service import Service as FirefoxService
from import Service as IEService
from import ChromeDriverManager
from webdriver_manager.firefox import GeckoDriverManager
from import EdgeChromiumDriverManager
from import IEDriverManager

Now, you can perform cross-browser testing with Python code.

Create a file called “” on your preferred IDE, then paste the following code to test different browsers (like Firefox, Chrome, Internet Explorer, Safari, and Microsoft Edge):

from selenium import webdriver
from import By
import unittest
class SeleniumCrossBrowserTest(unittest.TestCase):
   def setUp(self):
       Start the Selenium WebDriver in a browser of your choice.
       We use Chrome here but you can replace Chrome with one of the other options.
       # self.driver = webdriver.Safari()
       # self.driver = webdriver.Edge()
       # self.driver = webdriver.Firefox()
       self.driver = webdriver.Chrome()
   def tearDown(self):
       '''Quit the browser session once you are finished'''
   def test_sauce_labs(self):
       The setUp function initializes the right virtual machine browsers  on Sauce Labs
       Tests for a[text()] elements within the Sauce Labs' Homepage Platforms and Pricing
       element = self.browser.find_element(By.XPATH, '//a[text()="Platform"]')
       pricing_link = self.browser.find_element(By.XPATH, '//a[text()="Pricing"]')
if __name__ == '__main__':
II. Running Tests on Sauce Labs

Once you have your test script coded as above, you need to replace your environment variables with actual Sauce Labs credentials (a username and secret key). First, sign up for a Sauce Labs account if you don’t already have one.

Next, get your username and access key, which you can find here. You will use this access key in combination with your username to interact with Sauce Labs.

Then, assign the environment credentials within the code:

Username = =os.environment.get('SAUCE_USERNAME',None) #your sauce labs username
Access_key  = os.environment('SAUCE_ACCESS_KEY',None) #your sauce labs secret key

Now the tests look like this:

from selenium import webdriver
from import By
import unittest
import os
class SauceCrossBrowserTest(unittest.TestCase):
   def setUp(self):
       Start the Selenium WebDriver as a RemoteDriver connecting to Sauce Labs.
       username = os.environ.get('SAUCE_USERNAME')
       access_key = os.environ.get('SAUCE_ACCESS_KEY')
       caps = webdriver.ChromeOptions()
       sauce_caps = {
           "browserName": "Chrome",
           "browserVersion": "latest",
           "platformName": "Windows 10"
       caps.set_capability('sauce:options', sauce_caps)
       sauce_url = "https://{}:{}".format(username, access_key)
       self.driver = webdriver.Remote(
   def tearDown(self):
       '''Quit the browser session once you are finished'''
   def test_sauce_labs(self):
       The setUp function initializes the right virtual machine browsers  on Sauce Labs
       Tests for a[text()] elements within the Sauce Labs' Homepage Platforms and Pricing
       element = self.driver.find_element(By.XPATH, '//a[text()="Platform"]')
       pricing_link = self.driver.find_element(By.XPATH, '//a[text()="Pricing"]')
if __name__ == '__main__':

Now, it’s time to run the test. To do so, run the following Python code file in the terminal:


To view the results of your cross-browser testing, simply log back in to your Sauce Labs account and navigate to the Sauce Labs Dashboard.

Getting Started with Selenium Cross-Browser Testing on Sauce Labs

In this article, we discussed cross-browser testing and explained how to automate it with Python and Selenium. Cross-browser testing with Selenium ensures that your web application is compatible with all major browsers and that it provides a consistent user experience.

Due to the growing number of web browsers and sophisticated cloud applications, organizations need a more advanced cloud-based testing platform with increased processing capacity. The Sauce Labs platform provides more automation, greater test coverage, and overall application efficiency. It enables Selenium-based web application and cross-browser testing via the Sauce Labs cloud solution. For more information, you can check out our comprehensive Selenium on Sauce Labs documentation.

Faith Kilonzi is a full-stack software engineer, technical writer, and a DevOps enthusiast, with a passion for problem-solving through implementation of high-quality software products. She holds a bachelor’s degree in Computer Science from Ashesi University. She has experience working in academia, fin-tech, healthcare, research, technology, and consultancy industries in both Kenya, Ghana, and in the USA. Driven by intellectual curiosity, she combines her passion for teaching, technology, and research to create technical digital content.


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