What is Functional Testing?

Functional testing is the process of validating functionality of a software application. Pass or fail is the result of a functional test, because either a feature works as designed or it does not.

The purpose of functional testing is to validate that the requirements of the software application have been met. It is important because functional testing assesses an application’s fitness to be released to end users. While software engineering has evolved in the past decade, functional testing remains a core part of quality testing.

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The Types of Functional Testing

In discussions about functional testing it’s common to see many sub-types discussed. Types of functional testing include:


Smoke Testing

This type of software testing validates the stability of a software application.


Sanity Testing

This testing is performed after bug fixes have been made to software code. The goal is to ensure bugs have been fixed properly.


Regression Testing

Regression testing is performed to determine of code modifications break an application or consume resources.


User Acceptance Testing

User acceptance testing ensures that a software application works as designed for the end user.

Why Automate Functional Testing?

The modern era of software development requires continuous delivery and quality. This puts major pressure on testing teams. In order to keep pace with current go-to-market demands, DevOps teams must shift toward automating functional testing. With the help of automation, functional testing can become a more efficient and repeatable process.

Test Automation and Functional Testing

Automating functional testing is the perfect use case for automation. When implemented effectively, automation can turn manual functional testing tasks into a hands-off, constantly-running processes. Functional testing automation enables developers and testing teams up to focus on more complex and strategic work, which ultimately delivers a better application.

Pillars of Functional Testing

Functional Testing is based on the following pillars.


The goal of software testing is to ensure a quality product is released. With functional testing, quality issues are exposed so they can be fixed. Testing early and testing often helps testers catch potential issues on time. In contrast, waterfall or end of cycle testing doesn’t provide developers feedback they need when they need it to release quality apps quickly.

Customer Satisfaction

Functional testing validates and prepares a software application for use by end users. With solid functional testing, customers are delivered a high-quality application. To truly delivery customer satisfaction, testing must take into account the way users will engage with a web or mobile application. This means wide and thorough test coverage must be employed across the always-growing variety of devices and operating systems. Comprehensive test coverage requirements turn the volume of test cases into an unmanageable number without automation.

Meets Expectations

During the software development cycle, product requirements shift and iterate. With functional testing, product managers can see whether their expectations match the product that was developed. Testing early and often gives DevOps teams and product managers the right visibility to manage an efficient and optimal release.

Risk Reduction

When error-laden software is shipped, users notice, and organizations take a hit. Waterfall or end of the cycle testing can actually be a liability to web and mobile app product delivery. When organizations try to implement waterfall too quickly, it leads to bumps along the path. Tests in waterfall or end of cycle testing are not always created to work continuously. When issues emerge, there are often so many that teams are inundated, and defect management becomes unmanageable. With thorough functional testing, the risks of failed software releases are reduced.

Functional Testing in Action

To understand the nature of functional testing, here are some examples of how it is used in software development.


It examines how easily users can engage with the application including navigation of screens, buttons, and the overall UI.

Main Functions

Validating the core functions of an application. An example would be a complete login scenario to a banking application.


An important part of functional testing, accessibility testing checks if a system can be accessed. An example is whether a scenario can be completed through voice commands, which is necessary for the visually impaired.

Error Checks

Functional testing checks for errors using a set of specific conditions that could provoke a system error.

Functional Testing With Perfecto

The Perfecto Smart Automation Platform can help you take your functional testing to the next level, whether you are automating today or not. The Perfecto test automation testing solution helps you shorten the time it takes to execute and analyze your functional testing efforts. Our solution helps DevOps reduce the regression cycle time from weeks to days, hours, or minutes. We provide a lab with the devices and operating systems you need to get thorough and wide coverage for your functional testing.

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