What is Functional Testing

What is Functional Testing? Types & Examples (Complete Tutorial)

What exactly is meant by “functional testing”?
The software testing method known as “FUNCTIONAL TESTING” is intended to validate the software system in question by comparing it to the functional requirements and specifications. The goal of functional testing is to validate each individual function of a software application by simulating its use with the appropriate data and then comparing the results to the specifications outlined for that functionality.

Black box testing is the primary component of functional testing, and this type of testing does not care about the application’s source code. The User Interface, Application Programming Interfaces (APIs), Database, Security, Client-Server Communication, and other functionalities of the Application Under Test are all tested during this phase of testing. Testing can be carried out by hand or automatically using whichever method is preferred.

What do you test in Functional Testing?

Checking that a software system can perform its intended functions is the most important part of the Functional testing process. The primary emphasis is placed on –

Testing an application’s main functions is referred to as testing its mainline functions.
Testing the system’s usability on the most fundamental level is a part of this process. It determines whether a user is able to move freely through the different screens without encountering any obstacles.
Accessibility: Performs tests to determine whether or not the system is accessible to the user
Error Conditions: The utilisation of various testing methods to check for error conditions. It examines the system to see if appropriate error messages are displayed.

How to do Functional Testing

The process of conducting functional testing can be broken down into the following steps:

Gain an Understanding of the Functional Prerequisites
Determine which is the test input and which is the test data based on the requirements.
Compute the anticipated results using the given values for the various tests.

Functional Vs Non-Functional Testing:

Functional Testing Non-Functional Testing
Functional testing is performed using the functional specification provided by the client and verifies the system against the functional requirements. Non-Functional testing checks the  Performance, reliability, scalability and other non-functional aspects of the software system.
Functional testing is executed first Non-functional testing should be performed after functional testing
Manual Testing or automation tools can be used for functional testing Using tools will be effective for this testing
Business requirements are the inputs to functional testing Performance parameters like speed, scalability are inputs to non-functional testing.
Functional testing describes what the product does Nonfunctional testing describes how good the product works
Easy to do Manual Testing Tough to do Manual Testing

Execute test cases
Examine the difference between the actual and the expected results computed.

Evaluation of Functionality

Testing That Is Not Related To Function
The client will provide a functional specification, which will be used in the functional testing process. This testing will verify that the system complies with the functional requirements.
The performance, reliability, and scalability of the software system, as well as any other non-functional aspects, are put through their paces during non-functional testing.
The first step is to perform functional testing.
After the functional testing is complete, you should move on to the non-functional testing.
The functional testing process can be carried out manually or with the assistance of automation tools.
The utilisation of instruments will prove useful for this examination.
The inputs that functional testing is looking for are business requirements.
The non-functional testing process takes into account performance parameters such as speed and scalability.
Testing that is functional describes what the product is capable of.
The effectiveness of the product is evaluated through testing that is not functional.
Simple to carry out. Testing Done By Hand Testing by Hand Is Difficult To Perform
Tests such as Unit Testing are examples of functional testing.
Smoke Testing
Examining One’s Sanity
Examination of Integration
Examination of the “White Box”
Examinations using a Black Box
Testing for user acceptability
Regression Testing
Tests such as Performance Testing are examples of non-functional testing.
Testing Under Load
Volume Testing
Examining Under Pressure
Examination of the Safety
Examining the Installation
Examining the Level of Penetration
Examination of Compatibility
Examination of Migration
Instruments for Functional Testing
The most common functional testing tools are included in the following list. The following is an explanation of them:

Functional Testing Tools

testRigor is the most sophisticated codeless UI end-to-end functional testing tool available today. No matter how long or complicated the test cases are, automate the testing of them using plain English.
Popular open-source software for functional testing, known as Selenium
Functional testing made simple with HP’s Quick Test Professional (QTP).
JUnit is a testing framework that is primarily utilised for Java applications and can be applied to both Unit Testing and System Testing.
soapUI is an open source functional testing tool that is utilised principally for the purpose of testing web services. It is compatible with a variety of protocols, including HTTP, SOAP, and JDBC, among others.
This is a tool for performing functional testing on web applications called Watir. It makes use of the Ruby programming language and is capable of supporting tests that can be run in a web browser.


In the field of software testing, the term “functional testing” refers to the process of verifying that a system is operating in accordance with the functionalities outlined in a business document. This testing is performed as part of the functional testing process. The purpose of these tests is to determine whether or not the system satisfies all of its functional requirements!!!