UX & Visual Accessibility: 9 golden principles to master (Infographic)

visual accessibility hero image

For a while we wanted to do an article about UX and visual accessibility. For those of us who develop our tasks in the world of user experience (UX), and more specifically in relation to User Research, it is a matter of fundamental importance.

And this importance is given by the fact that, despite being mandatory in many countries, nobody seems to care. Furthermore, there are not a few government sites from different countries that have accessibility badges and ARE NOT ACCESSIBLE. Which, by the laws of those countries, is illegal.

And yet, accessibility is very secondary for them, accessibility badge or not.

Note: if you see the acronym a11y, it’s a short way to write accessibility. It’s formed by A + 11 (the letters between first and last character) + Y.

Since the usage of the a11y acronym is very common and widespread, it’s worth noting. besides, you’ll see it in this article.

Note: if you see the acronym a11y, it’s a short way to write accessibility. It’s formed by A + 11 (the letters between first and last character) + Y.

Since the usage of the a11y acronym is very common and widespread, it’s worth noting. besides, you’ll see it in this article.

Visual Accessibility in UX Design

First of all, we must make it clear that accessibility does not only refer to visual aspects. Accessibility can be for people with total or partial visual impairment (including color blindness and presbyopia). But there is also accessibility for the motor disabled (especially upper limbs), for the deaf impaired, for autistic people, for people with dyslexia, accessibility for people with neurological problems, etc.

But in this particular case, we are going to talk only about visual accessibility, how to do accessibility testing, and how to design inclusive interfaces.

To make the article more educational and entertaining, we have created an infographic with examples and references to master the 9 golden principles of visual accessibility in an easy and simple way.

visual accessibility infographic download

Always Use Plain Text

Fortunately, this is one of the most followed rules. However, it is number one as it is the one that causes the most problems.

This golden rule of visual accessibility could be stated like this:

Use plain text and HTML code, minimize or avoid including
information in images or downloadable files.

Why is it necessary to use plain text?

One of the main tools used by people with disabilities (not only visual disabilities, but others such as motor disabilities) are screen readers. All modern operating systems include screen readers, although there is specialized software.

The problem is that if you don’t use plain text, and the text is part of an image, or a file to download, or even plain text artificially placed in a different position using CSS, screen readers cannot read the information.

Want a good example? In this very same page, the Visual Accessibility Principles Infographic throws an alert, because content is in a downloadable PDF. Of course, we’re replicating and expanding the content of the infographic in this article.

However, if we had not included the content in plain text format (that is, this article), we would have a serious accessibility error

Use a logical layout

This rule may look a bit subjective (after all, what is “logical”?). The rule is as follows:

Layout has to be logical an easy to follow. DO NOT spread your
content all over the page!

What this rule means is that whenever possible we try to follow a logical sense, without big jumps in content.

This includes respecting content hierarchies, which is one of the basic UX and design rules. But also be logical in structure.

For example: if we have an image that illustrates the benefits of a balanced diet, and the text appears very far from said image, or even close, but with a heading that cuts off the text, it becomes very difficult to understand that both elements are related. This causes a cognitive overload that forces the content to be reread more than once.

Finally, there is a logical structuring of the headings. If we put an H1 heading, then an H4, then a paragraph, then an H2 heading, then another H1, and so on, we will create a site without structure. This lack of structure can be visual (although manipulable with CSS so that it doesn’t look like one).

UX wireframe and information architecture
UX and wireframes goes hand on hand. Wireframes are an excellent tool to view content structure before it’s “obscured” with content addition. The wireframes above are from one of our client’s projects and they are also ordered for IA (Information Architecture)

How do we know if the structure is logical?

As everything in UX, we need to do user testing. In this case, accessibility testing. There are many automated tools, but we recommend to hire an accessibility expert, or at least try doing accessibility testing using a screen reader yourself. Remember that screen readers are just one of the many assistive technologies that exists, so if you want to make sure you’re on the safe track, hire a knowledgeable UX company.

What happens if we don’t maintain a logical content structure?

The answer to this question is pretty obvious: our users are going to be very confused and will eventually leave our site.

But the fundamental consideration is that it affects screen readers, and makes it difficult for users to follow linear text.

Wireframes, information architecture and interactions
Looks complicated? In fact, this wireframe for another of our clients represents the logical structure for a simple landing page and all its interactions.

Provide keyboard navigation

Another golden rule of visual accessibility (and we could say that of UI in general):

Create your page so that users can navigate it with their
keyboards. DO NOT rely on the mouse alone!

Many users have trouble handling a mouse. Or simply, their mouse broke and they don’t have another to replace it!

Computer systems were created to be operated by a keyboard. Graphical interfaces require the use of devices such as the mouse, trackpads and others. But we must always verify that our site can be used without the need for an additional device other than the keyboard. Furthermore: in the case of screen readers, the page must be read even without a keyboard, only by verbal commands.

Design user interfaces for screen readers

Same as above points. By now, you’ll have notice that screen readers are paramount to visual accessibility (and again, for general a11y). There are other assistive technologies that you may consider, but this is the minimum to consider. If you fail at this, you’ll fail at all other technologies.

This complete rule can be stated as follows:

Prepare your page for screen readers. Use “alt” tags for images,
titles for links and proper HTML5 markup for each element

While screen readers are amazing, they’re kind of “dumb”. This means that they don’t see the page the same way as you do. You need to tell the screen reader “hey, this is some element, and this is another, and this should behave this way, and this should behave that way”. It may sound like a lot of work, but it’s incredibly easy.

Visual Accessibility: Braille reading
Assistive technologies aren’t new! Braille is a widespread assistive technology that existed way before any of us was born!

First of all, accessibility requires a bit of work (not a lot) and quite a bit of knowledge on the subject. To begin with, it is important that we know the rules of HTML5 perfectly. But also those of WCAG and ARIA (Accessible Rich Internet Applications)

ARIA is something that we are going to see many times, both in visual accessibility and accessibility for people with motor disabilities. The definition of ARIA is as follows:

(…) is a set of attributes that define ways to make web content and web applications (especially those developed with JavaScript) more accessible to people with disabilities.

It supplements HTML so that interactions and widgets commonly used in applications can be passed to assistive technologies when there is not otherwise a mechanism. For example, ARIA enables accessible navigation landmarks in HTML4, JavaScript widgets, form hints and error messages, live content updates, and more.


The simplest way to create an accessible website or user interface is to take the HTML5 code and make it linear, respecting the header and content text hierarchies.

Then add “alt” tags to the images. These tags should be descriptive of the image. Although technically the use of alt tags is mandatory in HTML5, they can be empty, and the code will still be valid. But if the image is important, we must clearly specify the content of the image.

Finally, we must consider items such as menus. The menus are very particular and have several conditions to be met in order to be accessible. And here ARIA is fundamental, as it defines certain roles for the elements. These roles must also be added on any element type other than text. For example buttons, accordions, tabs, interactive elements and even some links that have special behaviors.

Menus are an excellent example to understand and conceptualize accessibility implementation in depth. It the precedent principle just above this one, we saw that we must design websites to be used only with the keyboard. In this link to the W3 accessibility guidelines we will see how to create menus that use ARIA, and also what keyboard commands they should use

What would happen if we do not respect this rule?

Basically the site would be incomprehensible to a screen reader. Therefore, for the user. In some cases, the screen reader appears to have a psychotic attack.

For those who want to know what it feels like, try using a screen reader on a page without accessibility. You can deliberately create a very bad one, it is a very interesting experiment and it helps us to empathize with users

Accessible Contrast and Font Size

Probably the most disregarded of all these accessibility principles. A very easy to follow principle, yet completely ignored by most UI and web designers.

We can enunciate this rule like this:

Use contrasting text and readable font sizes. For AA compliance
you need a contrast ratio of 4.5: 1 and 7: 1 for AAA

For some strange reason, these “ratios” scare most web designers, who think it is impossible or some arcane mathematical formula. In the case of many UI designers, the case is even worse: they know it’s easy, they know it’s simple, but they consciously choose to ignore it. (Any UI designer knows that accessibility is a must in UXD and UID).

Visual Accessibility: Contrast Ratio and Font Size
Here we see how the huge NO button fails the minimum of 3.0 ratio required by WCAG2. For smalll text the required ratio would be 4.5

The important thing to keep in mind is that the text has a good contrast with the background. This is accomplished with color, and sometimes by size. This means that color is not a sufficient condition, but size matters.

The good news is that performing usability testing for this accessibility principle is actually very simple. Just visit one of the many color and size accessibility sites (try a Google search for “Contrast Checker” or just visit this site).

Why don’t web and UI designers apply this principle?

Of course we cannot speak for everyone. In the case of web designers, they may simply be unaware of its existence.

In the case of UI designers, it is usually due to aesthetic issues more linked to artistic visions than to user experiences.

Always use proper case in your web designs

This principle is generally respected, although not always. This principle can be summarized as follows:

Use proper case. DO NOT underline, capitalize or use capitalized

Although it may seem silly, not respecting this principle makes reading difficult for people with some type of visual impairment, but much more for people with neurological disabilities (including dyslexia).

Plus, it looks definitely bad!

Do not rely on color

A11y at its best. We should never trust that a color will convey a message. There are many reasons why doing so is bound to fail.

A perfect example is using red color to convey “error”, which is a convention that most know … in the West. For eastern civilizations, red is the color of luck! So if a person who has these cultural values ​​sees the color red, they will think that it is a good thing.

But we’re not talking about cultural accessibility or user experience anthropology (note to self: great topic for a future article). We are talking about accessibility for the visually impaired.

And you know what? That beautiful message in red will not be seen by those who suffer from some forms of partial color blindness such as protanopia, protanomaly or deuteranomaly. Or complete color blindness, such as cerebral achromatopsia (also known as color agnosia) or monochromacy.

And the same goes for green colors. And the blues. And any other color, as we are at it.

Usability Testing for Color Blindness
Usability testing for the colors to use in a dashboard from one of our past projects. This was a real challenge, because we needed to use a lot of colors, so it required a lot of testing until we found the correct combination

Attention: this does not mean that we cannot use color to convey messages. A button or a message in red will immediately catch our attention, which we can use in different ways.

But this itself implies that we should never rely on color alone. Because attracting attention does not mean that it is negative. It can also be used simply to create a CTA (Call to Action).

The important thing about this principle is: use color, and ALSO, descriptive text. Or at least an unambiguous icon that does not create confusion in the user experience about the element’s affordance

Use descriptive actionable elements

This does not correspond so much to visual accessibility as it does to the user experience around affordance and user expectations around future events.

Basically, this principle says:

The links and buttons must be descriptive. Avoid using vague
descriptions like “Click here”.

What this means is that by generating vague descriptions, the user loses control of the experience (this is called “locus of control”, see Shneidermann’s 8 Golden Rules of User Interface Design).

This is what happens in a user’s mind: What will happen if I click on the item? Why should I do it? Am I clicking the correct link or button?

These questions generate what is known as cognitive dissonance, or more commonly what in marketing and user experience is known as “friction”.

As we can see, this principle is not very specific to visual accessibility, but is more related to usability or psychological or neurological accessibility. However, since the perception of the element is visual, it is often included as part of these visual principles.

Additional benefits of describing future events.

This principle is widely used in marketing, and there are countless studies on the use of descriptive buttons or links, so I am not going to expand on the subject.

However, one of the greatest advantages that we will obtain by using this principle is the possibility of transmitting a message or call to action to the user. For example “Get your free book now!” is much more effective than “Click Here” or “Submit”. Or in other words: a very small effort will generate a much larger ROI.

And of course, the aforementioned “locus of control” that will allow us much more precise and safe user experiences. A button or link that describes exactly what will happen when activated will avoid many errors.

Note: unfortunately, this principle is the most used to deceive people, which in UX is known as “dark patterns”. In this particular case, buttons or links that describe false or misleading future events

Descriptive elements used as dark patterns
UK’s Daily Mirror use descriptive elements as dark patterns. Most people will click on the ambiguous AGREE TO ALL button, which means user will be tracked by everybody. The description of the permissions is also intentionally vague and confusing.

Allow users to zoom

This principle is the solution to a problem that happens mostly on mobile. It’s not common to find it on desktop, while not completely impossible.

This principle says:

Allow users to zoom your content. When a page is enlarged, it must
still maintain its linear structure

You probably see this fine in this article. But this is an example of bad visual accessibility: those 2786 numbers are barely visible for people with presbyopia or astigmatism. The application, (in this case the game Clash Royale) doesn’t allow to zoom

If you have vision problems (even mild, such as early presbyopia), surely at some point you had to zoom in on an element to enlarge it and be able to see it correctly.

In the first instance, we must start from the fact that if we must do this it is because the element (ergo, the website or mobile application) is not accessible. That would be enough for the “Hall of Shame”.

But it is even worse if the website or mobile application blocks the zoom intentionally, since it represents an intention to prevent the user from accessing the content. Literally an example of “accessibility denial”.

Again, this is much more common in mobile applications than desktop websites. One of the reasons given by those who do this (in fact, the most common) is that they need to negate the zoom to maintain the visual integrity of the application. Perhaps this is why within mobile applications, it is much more common in games. Within the technology industry, the games industry is famous for its lack of attachment to accessibility and usability. (Incidentally, the mobile gaming industry is also known for its love of dark patterns and dubious ethics.)

However, on desktop there is no reason to deny zoom. In most cases this happens simply due to lack of developer expertise. It would be very strange to find a site where the visual accessibility provided by zoom is denied for some real and logical reason.

Conclusion: Visual Accessibility is a must

Visual accessibility is not a burden, nor does it represent a longer development time, nor does it imply a growth in UX debt.

Nor is it an alms or concession to the user.

Quite the contrary: it is a powerful tool that allows us to empathize with users and generate richer and more humane experiences. A tool that allows us to generate more profit and interaction. It is a user engagement tool, ideal for marketing and Customer Experience (CX).

But it is also a tool that will prevent us from losing our business, or at least large sums of money. Lawsuits for non-compliance with accessibility laws are growing every year around the world.

Accessibility Lawsuits in US

In the USA they grew to more than 11,000 trials in 2019 (8.8% more than the previous year).

In Canada, fines go up to $ 15,000 (plus the cost of redoing the site).

In Europe fines of various values ​​are paid and the site is blocked until it does not comply at least with the WCAG Level AA directives.

In short:

Accessibility is a valuable tool. But it is also a moral and ethical obligation

Visual Accessibility Tools and Resources

Web Content Accessibility Guidelines

W3C Web Accessibility Initiative (WAI)


Google Lighthouse

Contrast Ratio Easy Calculator

WAVE checker

UBKAccessibilityKit by UBank for iOS

Axe accessibility testing engine

Accessibility in Official UK Sites

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