functional and non functional testing difference

Functional And Non Functional Testing

In software testing, functional and non functional testing are most important. In addition both testing will help to improve the quality of an application. So in this article we have tried to differentiate between functional testing vs non-functional testing.

What is Functional Testing? 

Functional Testing is a type of software testing that validates software products and services work as per the customer’s requirements or not. So, the main purpose of the functional testing is that each and every functionality should be worked as per customer’s requirements. 

What is Non-Functional Testing? 

Non Functional helps to increase the performance of the systems. So, there are different types of testing which are used in nonfunctional testing. The main purpose of this testing is that applications should have as per client’s expectation.

Difference between Functional Testing and Non-Functional Testing

Functional TestingNon-Functional Testing
Functional testing is based on how well the system performs.Non-functional testing is how well the system behaves.
Functional testing checks the functionality and the requirements of the system.Non-functional testing checks the performance of the system.
Functional testing is based on customer’s specificationsNon-Functional testing is based on customer’s expectations
It is easy to execute manually.It is difficult to execute non-functional testing manually.
Functional testing is performed before the non-functional testing.Non-functional testing is performed after functional testing.
Unit Testing  
Integration Testing 
System Testing 
UAT Testing
Regression Testing
Smoke Testing
Sanity Testing
Load Testing         
Performance Testing     
Stress Testing       
Reliability Testing      
Scalability Testing             
Security Testing          
Volume Testing
Example :
1. Verify that login page functionality with registered users
2. Verify that that login page functionality with unregistered users
Example :
1. Verify UI of Login page
2. Verify Login page response time
3. Verify that login page should not be break if more than expected users log in at a same time.


 So as above, we discussed the difference between functional testing  and nonfunctional testing. It will help to get a clear idea about functional and non functional.

Software Testing Interview Questions

Tricky Software Interview Questions

Scroll to Top