Cognitive accessibility on a website can be tested using a combination of automated scans and manual checks. Tools help to identify technical aspects such as contrast levels, form errors and missing help text, whilst manual testing focuses on language clarity, logical structure and the predictability of navigation. This article answers the most important questions about testing for cognitive accessibility, from the basics to practical implementation.
What are cognitive barriers on websites?
Cognitive barriers on websites are obstacles that prevent people with intellectual disabilities, learning difficulties (e.g. dyslexia), attention disorders (e.g. ADHD) or memory problems from understanding content or successfully completing tasks. The coverage of cognitive disabilities in the WCAG is deliberately limited because the spectrum of cognitive disabilities is very broad and many helpful measures are difficult to measure objectively.
Cognitive barriers therefore do not arise from a lack of technology, but from poor design decisions that place an unnecessary strain on users’ thinking and memory.
Typically, these include:
- Difficult language: Complex, text-heavy content is difficult to process
- Unpredictable navigation without a recognisable structure or orientation aids
- Error handling:Technical problems or errors can be difficult to resolve
- Complex designs:
- Overloaded or confusing user interfaces can be overwhelming
- Time limits put users under pressure
- A lack of consistency between pages, for example, different labels for the same function
Cognitive barriers do not only affect people with long-term disabilities. Older users, people under stress or those reading in a foreign language also benefit from clear, predictable design. Cognitive accessibility is therefore a key element of a good accessibility audit.
Which WCAG criteria cover cognitive accessibility?
The WCAG (Web Content Accessibility Guidelines) cover cognitive accessibility primarily through the principles of Perceivability, Operability and Understandability. Particularly relevant are success criteria from the ‘Understandable’ section, as well as individual criteria from the other principles that reduce cognitive load.
The most important WCAG criteria relating to cognitive accessibility are:
1.3.5 Identify input purpose – Enables autofill, reduces the burden on memory
1.4.3 Contrast (minimum): Sufficient colour contrast makes reading easier for people with visual impairments and cognitive limitations.2.2.1 Adjustable time limits: Users must be able to extend or disable time limits.2.4.6 Headings and labels: Meaningful headings help users navigate the page.3.1.1 Language of the page: The primary language must be specified in the code so that screen readers can read the content correctly.3.2.1 Focus: No unexpected changes in context when focusing on an element.3.3.1 Error detection: Form errors must be clearly described.3.3.2 Labels or instructions: Input fields require understandable labels and guidance.3.3.8 Accessible Authentication (Minimum) – No cognitive tests (e.g. remembering passwords, solving puzzles) without an alternative3.3.9 Accessible Authentication (Advanced) – Even stricter requirements (Level AAA)
WCAG 2.2 introduced additional criteria that take greater account of cognitive aspects, including 3.2.6 Consistent Help and 3.3.7 Redundant Input, which prevents users from having to enter the same information multiple times. Anyone conducting a BITV audit in accordance with the German standard also works with these WCAG principles.
How do you test cognitive accessibility manually?
Testing cognitive accessibility manually involves evaluating a website from the perspective of people with varying cognitive abilities. This requires structured testing processes, as many cognitive aspects cannot be detected automatically. The aim is to identify points where users might become confused, make mistakes or give up.
Checking language and comprehensibility
Read representative sections of text and ask yourself whether someone without specialist knowledge would understand this text.
- Text length: Are the sentences short and clear?
- Abbreviations: Are abbreviations explained when they first appear?
- Technical terms: Is there a glossary or explanations for technical terminology?
- Visual aids: Are texts supplemented with images or icons to aid understanding?
Use simple, easy-to-understand language; levels B1 to B2 are recommended for broad target audiences.
Assess navigation and structure
Navigate through the website without entering the URL directly.
- Predictable layout: Are key elements (search, navigation, help) always in the same place?
- Breadcrumbs: Are these present?
- Consistent menu labels: Are they used on all pages?
- Logical heading hierarchy: Is the H1 → H2 → H3 format adhered to?
Check whether links are clearly worded – i.e. not just ‘click here’ or ‘find out more’, but describing the link destination.
Testing forms and error messages
Deliberately fill in forms incorrectly. Check the following:
- Mandatory fields: Clearly marked (e.g. with an asterisk and text提示)?
- Input formats: Is the expected format explained (e.g. “DD.MM.YYYY”)?
- Error messages: Do they appear close to the relevant field?
- Error description: Is it explained what is wrong and how it can be corrected?
- Suggested solutions: Are specific correction instructions provided?
Ensure that users are made aware of errors and are given clear solutions to rectify them.
Testing authentication
Check each step of your login process against the following cognitive function tests:
- Memorisation: Are users required to remember a password?
- Copying/transcription: Does a one-time password (OTP) need to be entered?
- Spelling: Is correct spelling required?
- Puzzle-solving: Are CAPTCHAs with distorted text used?
- Calculations: Do users have to solve maths problems?
Permitted exceptions at AA level
Not everything is considered an impermissible cognitive task. According to WCAG 3.3.8, a cognitive task is permitted if at least one of the following conditions is met:
- Alternative method
An alternative authentication method without a cognitive test exists. - Support mechanism
A support mechanism is available (e.g. password manager, copy and paste).
Important: Websites must not block the pasting of passwords (copy and paste) or the use of password managers – this is a key support mechanism. - Object recognition
CAPTCHAs that ask the user to select all images containing a specific object (e.g. ‘Select all images with traffic lights’) are permitted at AA level. - Personal content
If the user has to recognise an image that they have uploaded themselves, this is also permitted at AA level.
Checking for distractions and time pressure
Moving content, media that starts automatically and time limits can present significant barriers for many users. People with the following conditions are particularly affected:
- Automatic media playback: Do videos/audio start automatically? Can they be stopped?
- Animations: Can moving content be paused?
- Time limits: Can users adjust time limits?
- Switch off before the time limit expires
- Adjust to at least 10 times the standard time
- Extend with a 20-second warning and at least 10 opportunities to extend
- Pop-ups/advertisements: Are there intrusive elements that cause distraction?
What can automated tools detect in terms of cognitive barriers?
Automated accessibility tools can check for some aspects of cognitive accessibility, but cannot cover all of them. They reliably detect technically measurable problems, but reach their limits when it comes to content-related and contextual issues.
Typically, automated tools can detect the following cognitive barriers:
- Missing or inadequate form labels and error messages
- Inadequate colour contrast, making text difficult to read
- Missing language markup in the HTML code
- Missing page titles or non-descriptive title tags
- Missing alt text for images
- Incorrectly used ARIA attributes that confuse screen readers
- Time limits without the option to extend them (in certain implementations)
What automated tools cannot reliably assess, however, is the actual comprehensibility of texts, the logical structure of navigation, or whether error messages are formulated in a way that is helpful in terms of content. Manual testing is essential for these aspects. Important: Automated scans typically cover some of the verifiable WCAG criteria, but they do not replace a full manual audit and do not constitute a legal certificate of compliance.
Which aspects are particularly important in a cognitive accessibility audit?
In a cognitive accessibility audit, you should pay particular attention to consistency, predictability and fault tolerance.
These three principles have the greatest influence on whether people with cognitive impairments can use a website independently.
No audit should fail to cover the following key areas:
- Consistency: Are navigation elements, labels and interaction patterns used consistently across all pages?
- Predictability: When clicking on a link or filling in a form, does the expected outcome occur?
- Error tolerance: Can users easily undo or correct mistakes without having to start from scratch?
- Cognitive load: Are users required to keep a lot of information in mind at the same time?
- Minimising distractions: Are there auto-playing videos, flashing elements or pop-ups that disrupt focus?
When prioritising identified issues, it is advisable to categorise them by severity: critical issues block basic functions; serious issues significantly restrict essential tasks; moderate issues make usage difficult even with existing workarounds; and minor issues have hardly any direct impact. This prioritisation helps development teams allocate resources effectively.
How can cognitive barriers be resolved after testing?
Cognitive barriers can be resolved after the test through targeted measures in content, design and code. The first step is to clearly prioritise the issues identified, followed by specific implementation measures, which should ideally be integrated directly into the development process.
Proven measures for resolving cognitive barriers include:
- Rewrite text using simpler language and explain or avoid technical terms
- Standardising navigation elements and introducing consistent labels
- Providing form fields with clear labels, instructions and understandable error messages
- Disabling media that starts automatically or incorporating a pause function
- Formulating page titles and headings so that they accurately describe the content
- Increasing colour contrast to at least 4.5:1 for normal text
It is important not to view these fixes as a one-off process. Websites are constantly changing, and new content and features can introduce new barriers. Regular reviews – for example, following major content updates or relaunches – ensure that progress is maintained and can be documented. Anyone who needs to inform customers or internal stakeholders about the current status will benefit from clear documentation of the measures taken and their success.
How we support cognitive accessibility at decareto
As compliance software for digital accessibility, decareto supports agencies, data protection officers and compliance teams in systematically testing websites for accessibility and maintaining an overview. In doing so, we specifically address the requirements relevant to cognitive accessibility testing:
- Automated scan against WCAG, BITV and BFSG: Our accessibility testing tool checks websites across all pages and identifies technically measurable issues such as missing labels, insufficient contrast and incorrect ARIA attributes.
- Prioritisation by severity: Issues found are classified by criticality so that development teams know where to start.
- Specific recommendations for action: For each issue, we provide clear guidance on how to resolve it, including code examples where helpful.
- Documenting manual issues: As not all cognitive barriers can be detected automatically, decareto allows manually identified issues to be recorded directly in the report.
Continuous monitoring: Hundreds of websites can be monitored continuously. Automatic notifications are triggered when changes occur, ensuring that new barriers are detected at an early stage.Sharing and documenting reports: Reports can be shared directly with clients, either as a PDF or via a shared link, optionally featuring your own logo using the white-label function.
If you wish to systematically check websites for accessibility whilst taking cognitive aspects into account, get started with decareto now and see for yourself the depth of our testing and the workload we can take off your hands.
