Is usability testing functional or non-functional?

Usability testing is a method of non-functional testing that examines how well the product is working for users. There are a wide variety of usability testing tools to help you get started. Implementing both functional and non-functional testing creates an ideal end-user experience and ensures your product is working at the highest standard of functionality. 

We'll dive deeper into the ins and out of functional and non-functional testing and why usability testing is considered a non-functional form of testing.

What is usability testing?

Usability testing is observing how users interact with—and how they respond to—your product. These days, usability testing can include remote, unmoderated tests that are set up beforehand and taken by your ideal user. For optimal results, explore when you should use unmoderated usability testing in your product design process.

From preference testing to discovering where users get stuck and confused, usability testing quickly highlights areas for improvement both before and after a product launch. Types of usability testing for products include: 

• Visual design testing: gather insights about creatives, designs, videos, or other visual elements
• System usability evaluations: measure a product or service’s ease of use
• Card sorting: understand how contributors group content and label categories
• Needs and frustrations discovery: identify opportunities to improve customer experiences or activities
• Web/mobile/prototype evaluations: observe people using a pre-production product or experience 
• Information architecture and navigation testing: measure how easily users find content within a site’s navigation

What is functional testing?

Functional testing tests if the features and elements of the product work. It tests the functionality of your design against the requirements set for your product. Unlike non-functional testing, functional testing doesn’t focus heavily on how your product performs, or if it meets customers’ expectations. 

What is non-functional testing?

Non-functional testing is software testing designed to check the performance, usability, and other elements of the product that aren't necessary for functionality. These elements aren't required for the product to function but contribute to the overall user experience.

Non-functional testing examines how well the product works and increases the usability of the product. Overall, non-functional testing tests everything else functional testing doesn't. 

Why usability testing is considered non-functional testing

Usability testing is a form of non-functional testing because it assesses how the product performs for the user. Usability testing gauges the accessibility of applications and if users can complete tasks using your product. By testing the usability of a product, you’re performing non-functional testing.

Designers should test early and often to discern issues with your product’s usability. Understanding the unique qualities of functional and non-functional testing will ensure you receive the results you need to build better products and experiences for your customers.