Running Selenium Tests in Docker: A Beginner-Friendly Guide

#selenium #testing #docker #testautomation

Selenium is one of the most popular tools for automating web application testing. But as your projects grow, managing different browser versions, drivers, and dependencies across multiple environments can quickly become a hassle. That’s where Docker comes in — offering a clean, consistent, and isolated environment to run your Selenium tests, no matter where you are.

Docker makes it easier to set up, run, and scale your Selenium tests by packaging everything into lightweight containers that behave the same across machines and platforms.

In this blog, we’ll walk you through:

What Docker and containers are
Why Docker is a great fit for Selenium testing
How to install Docker
And how to run your Selenium tests in Docker using a simple setup Let’s get started!

What are Docker and Containers

In today’s software industry, containers have become a popular choice because they’re lightweight, portable, and designed to ensure consistency across different environments.

You can think of a container like a shipping container — no matter where it’s moved, it safely carries everything inside. Similarly, a software container packages your application along with all its dependencies, keeping everything it needs to run neatly bundled and isolated from the outside system.

This is where Docker comes in. Docker is an open-source platform that makes it easy to build, package, and run applications inside containers. It ensures your application runs the same way everywhere — whether it’s on your local machine, a server, or in the cloud — solving the classic “it works on my machine” problem.

A container includes everything an application needs — the code, runtime, libraries, system tools, and settings — in a standalone, executable unit.
The real advantage is consistency and isolation. No matter where you deploy them, containers behave predictably, providing a reliable and repeatable environment for developing, testing, and deploying applications.

Use of Docker for Selenium Testing

Docker is an excellent fit for Selenium automation testing, and here’s why it’s becoming so popular:

One of the biggest challenges in testing is setting up a clean and consistent test environment. Often, teams face delays or limited testing because environments are either unavailable or unreliable. Docker solves this by creating fresh, isolated environments for every test run, which are automatically removed after the tests are complete. This ensures you always test in a clean, predictable setup.

It’s especially useful when dealing with Cross Browser Testing, where maintaining multiple Browser-OS combinations can get complicated and time-consuming. With Docker, you can spin up multiple containers with different browser and OS setups on the fly, running tests in parallel — making the entire process faster and more scalable.

Another advantage is how efficiently Docker uses your system resources. You can run multiple containers on a single machine, making the most out of the available hardware without conflicts or heavy setup overhead.

In short, Docker makes Selenium test execution:

Consistent — no more “it works on my machine” issues.
Isolated — each test runs in its own clean environment.
Parallel-friendly — easily run multiple tests at the same time.
Lightweight — no need to install browsers, drivers, or extra tools locally.

It simplifies test management, speeds up execution, and ensures your results are reliable and repeatable.

Docker Installation

Go to this link to download the docker desktop installer. Based on your operating system select your installer.

Open the installer and install the Docker
After successful installation open the Docker Desktop and accept the agreement and we can skip other steps.

The Docker Desktop will be displayed as below:

After successful installation, we can check the docker version using the command “docker –version”.

Run Selenium Tests in Docker

Now Docker Desktop is configured in the system. We can download the docker pull images and execute them. We can create a Docker image step by step from the start or pull an already configured base image from the Docker hub and then add on to it.