What is Cucumber tool used for?

The Cucumber tool is used to run automated acceptance tests written in plain English. It supports Behavior Driven Development (BDD), letting business analysts, developers, and testers describe how an application should behave in a shared Given-When-Then format that Cucumber then executes as real tests. In short, it turns readable specifications into living, executable documentation.

Because scenarios read like ordinary sentences, non-technical stakeholders can review and even help write them, which improves collaboration and keeps requirements aligned with the actual tests. For the foundational concept, see what is Cucumber, or explore the TestMu AI Cucumber testing guide.

What Is Cucumber and Why Teams Use It

Cucumber is an open-source tool that reads executable specifications written in plain text and verifies that the software does what those specifications say. Central to it is a parser called Gherkin, which lets expected behaviors be expressed in a structured language that customers, product owners, and engineers can all understand. Teams use Cucumber not just to automate tests, but to build a shared understanding of requirements before a line of production code is written, reducing costly misunderstandings between business and engineering.

Main Uses of the Cucumber Tool

• Acceptance testing: Validate that features meet business requirements using scenarios anyone can read.
• Behavior Driven Development: Define behavior first in plain language, then automate it, keeping specs and tests unified.
• Living documentation: Feature files describe the system and stay accurate because they are the tests themselves.
• Collaboration: Give business and technical teams one shared language, improving communication and trust.
• End-to-end automation: Orchestrate UI testing, mobile, and API checks from a single readable layer.

How the Cucumber Tool Works: Gherkin and Given-When-Then

Cucumber scenarios live in a feature file (ending in .feature). Each scenario uses the Given-When-Then pattern to describe context, action, and expected outcome. Here is a simple checkout example:

Feature: Shopping cart checkout

  Scenario: Purchase an item as a logged-in user
    Given the user is logged in
    And the cart contains one item
    When the user completes checkout
    Then an order confirmation should be displayed

Each sentence maps to a step definition in code. Cucumber matches the text, runs the linked method, and reports pass or fail, which is how business-readable text drives real automation.

Using Cucumber With Selenium

Cucumber does not drive the browser by itself; it orchestrates scenarios while a tool like Selenium automation the UI. A Java step definition connects Gherkin to Selenium WebDriver commands:

import io.cucumber.java.en.When;
import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;

public class CheckoutSteps {
    WebDriver driver; // initialised in a hook

    @When("the user completes checkout")
    public void completeCheckout() {
        driver.findElement(By.id("checkout")).click();
        driver.findElement(By.id("confirm-order")).click();
    }
}

To learn the wiring in detail, see how do we use Cucumber in Selenium, or follow the TestMu AI Selenium Cucumber tutorial.

Cucumber vs Selenium: What Each Does

• Purpose: Cucumber describes behavior in plain language; Selenium automates browser interactions.
• Audience: Cucumber scenarios are readable by anyone; Selenium code is written by engineers.
• Layer: Cucumber is a BDD orchestration layer; Selenium is the execution engine underneath.
• Together: They complement each other, Cucumber defines the what, Selenium performs the how.

Common Mistakes and Troubleshooting

• Writing scenarios like scripts: Steps should describe behavior, not raw UI clicks. Keep them declarative so they stay readable and stable.
• Undefined steps: Mismatched step text produces an undefined step. Ensure the Gherkin sentence exactly matches the step-definition annotation.
• Overusing scenario outlines: Too many data rows make failures hard to read. Reserve them for genuine data variation.
• Sharing state via static fields: This causes flaky tests. Use dependency injection or a shared context object instead.
• Skipping hooks: Forgetting Before and After hooks leaves drivers open or state dirty between runs.

Run Cucumber Tests Across 3000+ Browsers and Devices

Cucumber defines what to test, but real quality comes from running those scenarios across the browsers and devices your users actually have. With TestMu AI, you can execute your Cucumber and Selenium suites in parallel across 3000+ real browsers, operating systems, and device combinations, turning a plain-English feature file into broad cross-browser testing coverage. Point your WebDriver at the cloud grid, run scenarios concurrently to cut execution time, and capture logs, screenshots, and videos for every step through the TestMu AI automation testing platform, all without maintaining your own infrastructure.

Conclusion

The Cucumber tool is used to turn plain-English Gherkin scenarios into executable acceptance tests, aligning business and engineering around shared, readable specifications. It supports BDD, produces living documentation, and pairs with Selenium or Appium to validate real behavior across web, mobile, and API layers. Combine it with a cloud grid and you get both collaboration and broad, reliable coverage.

Frequently Asked Questions

What is the Cucumber tool used for?

Cucumber is used to run automated acceptance tests written in plain English. It supports Behavior Driven Development, letting business analysts, developers, and testers describe how an application should behave in a shared Given-When-Then format that Cucumber then executes as real tests.

Is Cucumber a testing or development tool?

Cucumber is primarily a test automation tool, but it is also a collaboration framework. It validates software against plain-language specifications while giving technical and non-technical stakeholders one common language to define behavior, so it spans both testing and requirements work.

What is Gherkin and Given-When-Then in Cucumber?

Gherkin is the plain-text language Cucumber reads. It uses keywords like Feature, Scenario, Given, When, and Then to describe context, action, and expected outcome, so anyone can understand a test even without programming knowledge.

Is Cucumber only for web application testing?

No. Cucumber orchestrates scenarios and can drive web tests with Selenium, mobile tests with Appium, and API tests with REST clients. It is not tied to a single layer, which is why teams use it for end-to-end acceptance testing across web, mobile, and services.

Does Cucumber require coding knowledge?

Writing Gherkin scenarios needs no coding, so product owners and manual testers can contribute. However, connecting those scenarios to the application through step definitions requires code in a language such as Java, JavaScript, or Python.

What are the main benefits of using Cucumber?

Cucumber improves collaboration through readable tests, produces living documentation that stays in sync with behavior, supports many languages, and integrates with Selenium, Appium, and CI pipelines, making automated tests easier to write, review, and maintain.

• What is Cucumber?
• How do we use Cucumber in Selenium?
• What is BDD testing?
• What are the major features of TestNG?
• What are the limitations of Selenium?