1.3.3 Sensory Characteristics

1. What is the goal of this criterion?

Imagine someone giving you directions over the phone: “Take the green door to the right of the round sign.” If you struggle to tell green from red, or can’t see the sign at all, you’re left standing there clueless. Many people experience exactly that on the web when instructions only refer to how elements look or where they are.

Some people are blind or have low vision and use screen readers or other assistive technologies. Others have a colour vision deficiency – around 8 % of men and 0.5 % of women of Northern European descent – or cognitive disabilities. All of them run into trouble when instructions only say: “Click the red button” or “Select the icon at the bottom right”.

The goal of Success Criterion 1.3.3 is for instructions to be understandable for everyone – regardless of whether someone can perceive colours, shapes, positions or sounds. Additional cues such as visible labels or names make content accessible to all.

2. What exactly does it require?

This is a Level A criterion and therefore fundamental: instructions for understanding and operating content must not rely solely on sensory characteristics. That means:

Don’t rely on colour alone: “Click the green button” isn’t enough – better: “Click the green ‘Next’ button” or simply “Click ‘Next’”.

Don’t rely on shape alone: “Press the round button” isn’t enough – better: “Press the round ‘Submit’ button” or simply “Press ‘Submit’”.

Don’t rely on position alone: “Use the icon in the top right” is problematic – better: “Open the main menu in the top right (the three-line icon)” or “Open the main menu”.

Don’t rely on size alone: “Click the big button” doesn’t work for everyone – better: “Click ‘Buy now’”.

Don’t rely on sound alone: “Continue after the beep” with no other cue isn’t enough – add a text message, for example.

You may use sensory characteristics in addition – they just mustn’t be the only information. Combining a clear name with a visual cue is actually ideal. When colour carries information, Use of Color applies as well.

3. Why does it matter for accessibility?

Imagine navigating a website with your eyes closed – with nothing but a screen reader to help. If it says “Select the blue icon on the right”, you’re stuck. You can’t hear colours and you can’t see positions.

Instructions that don’t depend on the senses alone create accessibility because they:

• let blind and visually impaired people find controls even if they can’t perceive shape or position,
• help people with colour vision deficiencies who can’t tell certain colour combinations apart,
• support people with cognitive disabilities who find purely visual cues difficult,
• help screen reader users who navigate to elements by their name,
• help deaf and hard of hearing people when cues would otherwise only come as sounds,
• help in difficult situations – bright sunlight, small displays or sound switched off.

And finally: clear, unambiguous instructions improve usability for everyone – including people without disabilities who just want to find their way quickly.

4. How to meet the criterion

Meeting it is easier than you might think – it’s mostly about careful wording and good labels. A few proven strategies:

Name things clearly:

• Instead of “Press the green arrow” → “Press ‘Next’”
• Instead of “Select the round icon” → “Open the user menu”
• Instead of “Click top right” → “Click ‘Settings’”

Combine name and appearance:

• “Click the red ‘Delete’ button” (label plus colour as extra information)
• “Open the main menu using the three-line icon in the top right” (function plus icon plus position)
• “Select ‘Save’ (green button)” (label plus colour for reinforcement)

The label has to match the instruction: if your instruction says “Click ‘Settings’”, the element must actually be called that – visibly and in the code. For icon buttons, that means:

<button type="button" aria-label="Settings">
  <svg aria-hidden="true" focusable="false">…</svg>
</button>

Requirements for text alternatives for icons are covered by Non-text Content.

Use structural cues:

• Refer to sections by their heading: “In the ‘Contact information’ section you’ll find …”
• Name options instead of pointing at them: “Choose one of the options: Standard or Premium.”
• Refer to form fields by their label: “Enter … in the ‘Email address’ field”

For more complex instructions:

• Offer several ways to identify the element: “Click ‘Next’ (the blue button at the bottom right)”
• Provide context: “In the sign-in form, select ‘Register’”

5. Why this criterion matters for businesses

Instructions that don’t rely on the senses alone may sound theoretical – but they’re a real advantage for any business.

1. Better usability for everyone

Clear, unambiguous instructions reduce confusion and drop-offs. When users immediately understand what to do – without guessing which of five blue buttons is meant – they reach their goal more easily. That applies to everyone, not just people with disabilities.

2. Fewer support requests

“I can’t find the button” or “Where’s the icon?” – requests like these often stem from unclear instructions. Clear descriptions can cut support effort.

3. More robust technology

Clear names don’t just work with screen readers – they also help voice control, automated tests and translation.

And then there’s the law: since 28 June 2025, the European Accessibility Act has applied to many consumer products and services; Germany implements it through the Barrierefreiheitsstärkungsgesetz (BFSG). The benchmark is EN 301 549, which refers to WCAG 2.1 Level AA – 1.3.3, as a Level A criterion, is part of it. Public sector bodies have their own obligations. (General information, not legal advice.)

6. The success criterion in the W3C’s words

Success Criterion 1.3.3 Sensory Characteristics (Level A)

Instructions provided for understanding and operating content do not rely solely on sensory characteristics of components such as shape, color, size, visual location, orientation, or sound.

Note: For requirements related to color, refer to Guideline 1.4.

In short: instructions must not depend solely on the shape, colour, size, position, orientation or sound of elements.