Both terms Accessibility Testing and Usability Testing seems similar.

Are they both same? Or is there any difference between Accessibility Testing and Usability Testing?

9 Answers 9


This answer does not provide the exact definitions, just the differences.

1. Accessibility Testing

Testing carried out to verify whether the application is user-friendly to the physically disabled user.

For example, we can consider the Kindle e-book application. For this application, we check whether the application has the feature to read the e-book content and also to ensure whether it matches the written content so that it helps the blind people to access the application.

By default, Edge browser has reader functionality so that you can check whether your site has good accessibility (Right-click -> Read aloud)

2. Usability Testing

Testing carried to verify whether the application is user-friendly to the non-disabled user.

For example, we can consider the same Kindle e-book application. It should have proper UI designs and proper navigation. For example, clicking on the app logo should navigate to the homepage.

Ola ranks first than the Uber because of its Usability.

  • I don't have enough rep for a downvote but I strongly disagree with "Testing carried to verify whether the application is user-friendly to the non-disabled user." Just because something is accessible does not mean it's usable.
    – MonkeyZeus
    Mar 13, 2020 at 19:13
  • 1
    I have mentioned this is for usability not for accessibility. Please be clear with my answer. Accessibility is for physically challenged user and usability for normal users. Physically challenged user(visually impaired) can't able to use a application by using a mouse here keyboard shortcut action will helps this is accessible and known as accessibility testing Mar 14, 2020 at 2:04

First, you have to understand the difference between UX and UI

In simple words

UX: Focuses on designing a UI that enhances the user experience. Means it ensures that the UI design is designed with ease of use, easiness in Accessibility and feel in looks.

UI: On the other hand, ensures endpoints for a user to interact with the product.

So a simple UI can just have some form field and a button. But a UX design will have light colours, 3D animations, smooth transitions between pages etc to make the experience more interesting.

So coming back to your question:

Appearance testing:

This tests mainly the UI implementation it tests the "looks and feel" of the UI/UX design

Things that you will test includes:

  1. Colours
  2. Fonts
  3. Alignment
  4. Overlapping etc

Accessibility testing:

As per https://developer.mozilla.org/en-US/docs/Learn/Accessibility/What_is_accessibility

So what is accessibility?

Accessibility is the practice of making your websites usable by as many people as possible. We traditionally think of this as being about people with disabilities, but the practice of making sites accessible also benefits other groups such as those using mobile devices, or those with slow network connections.

You might also think of accessibility as treating everyone the same, and giving them equal opportunities, no matter what their ability or circumstances. Just as it is wrong to exclude someone from a physical building because they are in a wheelchair (modern public buildings generally have wheelchair ramps or elevators), it is also not right to exclude someone from a website because they have a visual impairment. We are all different, but we are all human, and therefore have the same human rights.

Accessibility is the right thing to do. Providing accessible sites is part of the law in some countries, which can open up some significant markets that otherwise would not be able to use your services or buy your products.

So it doesn't just focus on disabled persons, it focuses on the human race as a whole.

It tries to make your system reach as many people as possible.

  1. People who cannot read or hear or see
  2. People who don't know what button is, what a text field is etc
  3. People who are slow, ( Having more time session time out ) and so on.

Usability testing:

Here we are trying to make the system as easily usable and understandable as possible

Here we ensure the following things:

  1. How easily can a person use the system without reading manuals
  2. How easily can a person move different components without being distracted by unnecessary features
  3. What is the learning curve for the new feature
  4. Does the UI design confuse the person? for example, the button says delete but it just archives the content
  5. and so on


So, accessibility is how you make your product reachable to vast, while usability is about making it easier for everyone to use.

So in some cases, if you add too much accessibility or usability features then it could affect usability or accessibility respectively.


You enable background read by default for all users and now when a user who doesn't have hearing disability uses it, he/she has to wait till the whole page is read and the background sound might irritate him. This will reduce the usability of the page.

Now if instead, we had too many animations for giving a nicer user interaction then people with reading difficulty, or are using slow internet connection can face difficulty in accessing the information. SO here more usability feature reduced the accessibility

Hence we need to ensure a balance between the two.


As others have said, usability refers to the ability for people to successfully use your product. Accessibility refers to the ability for people with disabilities to successfully use your product.

Do you notice something about these two things? Yes... One is a subset of the other. Unless you define "people" as excluding those with disabilities, then usability testing includes and requires accessibility testing.

So the difference therefore is just that one of these things is smaller in scope than the other. Unfortunately, humans are often not very good at considering issues that they have not experienced. So we've had to call out and distinctly name the specific subset of usability testing that relates to those with disabilities, so as to give a framework to Engineers without disabilities to work from.

Calling part of usability testing "accessibility testing" is just a tool to help make sure that all of the necessary usability testing is considered and done appropriately, when the developers are not personally impacted by those disabilities.


You might argue they are the same - if you cannot access something you cannot use it and if you cannot use something (in a meaningful way) you cannot really say it is accessible. It is a thin line between those terms, at least linguistically.

However, those terms usually mean something specific. So, accessibility in the context of software development and testing means accessibility to people whose senses (sight, hearing, etc.) are somewhat diminished in comparison to most people around, so the testing is more focused in this direction.


Below is the difference:

Accessibility refers to the website is available and can be easily accessed by a normal person or even disabled person. Accessibility testing focuses on testing if the website is accessible to disabled people and can be used by various tools used by them.

Usability means to deal with how easy and intuitive a website is to use. If the users can use a website without any instructions, we would call it highly usable. Usability testing focuses on measuring the ease at which website can be used.

I find link https://medium.muz.li/the-ultimate-guide-difference-between-usability-and-user-experience-afb757ded1c4 more useful to explain the difference.


From my perception, usability and accessibility are terms usually misused and confused. These two plays an essential role in enhancing UX and performance of a product, so these two are a critical quality indicator for interactive products/systems.

I believe that you have learned the difference between these two. The principal benefit of conducting accessibility testing is, it will uncover usability issues too. The end goal in both usability and accessibility testing is to discover how easily people can use a product.

Both usability and accessibility testing should start right at the beginning of product design to succeed in development iterations in final delivery.


Usability testing is to understand if your product is actually usable by the target audience of the product (whether it is web site, app, hammer or stairs). Note that it may mean that you may largely ignore groups of users that are not in your target - i.e. testing an app for "drivers with paralyzed left hand" you may not need to include legally blind person or someone who can freely use both hands. There is also no official standards what "product is usable" means - every company decide what it means for they product and define they own goals.

Accessibility testing is often testing to satisfy accessibility compliance requirement - either mandated or self-imposed. Legal requirements for meeting accessibility standards vary significantly between types of products and types of consumers. I.e. buildings have very strict requirements that can't be bypassed, while requirements for software is generally more relaxed and frequently self-imposed. Products provided for governmental use (either to use by or to distribute by) often have higher requirements, particularly in software.

The goal of accessibility testing (unlike usability) is to makes sure that every single user that have a reason to use the product is able to do so. It includes people of all ages, physical ability, with all kinds of impairments. In real world there are cases when only subset of population can use a product - stairs on a nuclear submarine have less accessibility requirements than one in the town hall. In software world there rarely are any such constraints on types of users and most software tested for being compliant for defined guidance for the platform it uses.

One more difference is amount of creativity involved in each kind of testing. Accessibility testing usually is pretty mechanical activity ("25. Can use keyboard to reach all elements" - check) done by whoever is doing QA on they own. The usability testing may involve coming up with scenarios to try, parameters to measure, picking "target" users and understanding why users fail. Depending on a company the usability testing may also be actually working with external users and watching them to go through use cases.

Examples of accessibility compliance documents - for web sites often WCAG, for apps each platform has specific guidance like Apple - Accessibilty in iOS or Microsoft - Accessibility in UWP.


Every software testing company performs accessibility and usability testing.

Following is the main difference between both:

Accessibility testing: It is performed to ensure that the application being tested is usable by people with disabilities. Accessibility testing is a subset of usability testing wherein the users under consideration are people with all abilities and disabilities.

Usability testing: Usability means to deal with how easy and intuitive a website is to use. Moreover, it involves checking if a new user can understand, learn & use the application easily, help contents, system navigation, pleasing design, etc. Usability practice often does not sufficiently address the needs of people with disabilities.

So, accessibility is how you make your product reachable to vast, while usability is about making it easier to use for everyone.


Accessibility Testing is a crucial testing type within Usability Testing as a whole (according to ISTQB Syllabus)

Target audience for Accessibility Testing: enter image description here

Users with disabilities (any form of disabilities)

Target audience for Usability Testing: enter image description here Common users of those applications

Important Part:

Types of testing items/process conducted or performed part of Usability Testing:

  • Usability Requirements
  • User Experience Evaluation
  • Usability Evaluation
  • Usability Risks
  • User Survey
  • Usability Test Report

Types of testing items/process conducted or performed part of Accessibility Testing:

  • Accessibility Evaluation
  • Accessibility Risks
  • Accessibility Test Report




Hence Usability Testing and Accessibility Testing has different needs and they have different test cases to perform and they are not same.

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