Freely available across all editions and plans of Accessibility Cloud
What can ACAI test for?
In addition to the rules provided by axe-core, QualWeb, and the ACAI-engine, ACAI-AI introduces a set of AI-powered tests that target issues which are difficult or impossible for traditional rule-based engines to detect. ACAI also checks a website’s accessibility statement against the requirements of the EU Web Accessibility Directive (WAD). New tests are added frequently.
AI-powered tests
Alternative text must be accurate
acai-alt-text-inaccurate – WCAG 1.1.1
Detects alternative text that does not correctly describe the content of an image. Alternative text exists to provide a textual equivalent for users who cannot see visual content, whether due to visual impairments, slow internet connections, or disabled images. When alternative text is inaccurate or invalid, it becomes misleading rather than helpful, failing to convey the intended information and undermining accessibility for a significant portion of users.
Alternative text must be descriptive
acai-alt-text-nondescriptive – WCAG 1.1.1
Alternative text should clearly describe the content it represents. Identifies alternative text that is too vague or generic to be useful, such as “logo”, “image”, “picture”, “photo”, or “flag”. These terms fail to convey meaningful information and do not help users understand the content of the image.
Alternative text must be in the correct language
acai-alt-text-lang-mismatch – WCAG 3.1.2
Flags cases where the alternative text is written in a different language than the one specified in the containing element’s lang attribute or the document’s language. When there is a mismatch, screen readers may mispronounce the alternative text, making it difficult or impossible for users to understand.
Alternative text must not contain symbols that cause screen reader noise
acai-alt-text-symbols-noise – WCAG 1.1.1
Identifies symbols or special characters in alternative text that produce unwanted or confusing output when read aloud by screen readers. This includes repeating punctuation marks such as “—” or “***” and decorative separators like |, /, and –. Such characters create unnecessary audio clutter for screen reader users, distracting them from the main content. These symbols should not appear in alternative text unless they are part of the actual visible text in the image.
Data visualizations must be described in alternative text
acai-alt-text-chart-undescribed – WCAG 1.1.1
Detects charts, graphs, and other data visualizations that lack meaningful alternative text. Without a text description, users who cannot see the visual content have no way to access the data being presented.
Alternative text must not contain typos or grammatical errors
acai-alt-text-typo – WCAG 1.1.1
Detects spelling and grammar mistakes in alternative text. Such errors can confuse screen reader users, reduce clarity, and make images harder to understand. Correct, clear alternative text ensures accurate interpretation for people relying on assistive technologies.
Alternative text must not repeat brand name or marketing slogans
acai-alt-text-brand-spam – WCAG 1.1.1
Identifies alternative text that has been used to insert brand names, marketing slogans, or other promotional content rather than providing a genuine description of the image. This gives users no meaningful visual information, making the alternative text useless for screen readers and reducing understanding for people who rely on them.
Accessibility statement must exist
acai-statement-exists – WAD
Checks whether the website has an accessibility statement. Under the EU Web Accessibility Directive, public sector websites must publish one. The statement tells users how accessible the website is, which parts are not accessible, and how to report problems or ask for information in an accessible format. Without it, users do not know what to expect or where to turn for help.
Accessibility statement must have information about the statement’s preparation
acai-statement-preparation – WAD
Checks whether the accessibility statement says when it was prepared, when it was published and when it was last reviewed. The Web Accessibility Directive’s model statement requires the preparation date and recommends a review at least once a year. These dates show users whether the information is still current. An undated statement may describe an older version of the website.
Accessibility statement must have technical information listed
acai-statement-technical-information – WAD
Checks whether the accessibility statement explains how the website’s accessibility was assessed. That means its compliance status, when it was tested, whether the tester was internal or external and who they were, which pages or content were tested and how they were chosen, and a link to the full test report. The compliance status and the assessment method are required, and the other details are recommended. This lets users and monitoring bodies judge how reliable the statement’s claims are.
Accessibility statement must disclose inaccessible content
acai-statement-inaccessible-content – WAD
Checks whether the accessibility statement lists the content and features that are not accessible, if there are any. The Web Accessibility Directive requires the statement to name these parts, explain why they are not accessible, and point to accessible alternatives where they exist. Without this list, users only find the barriers when they run into them.
Accessibility statement must include feedback mechanism
acai-statement-feedback-mechanism – WAD
Checks whether the accessibility statement includes a feedback mechanism, such as a contact form or an email address, and contact information for the people responsible for accessibility. The Web Accessibility Directive requires the statement to describe and link to this mechanism, so users can ask for content they cannot access.
Accessibility statement must have a way of reporting problems
acai-statement-problem-reporting – WAD
Checks whether the accessibility statement tells users how to report an accessibility problem they found on the website. The Web Accessibility Directive requires a way to notify the website owner when the website fails to meet the accessibility requirements. A clear way to report problems turns each barrier a user meets into something the website owner can fix, instead of a dead end.
Accessibility statement must include enforcement procedure
acai-statement-enforcement-procedure – WAD
Checks whether the accessibility statement explains the enforcement procedure: who users can turn to if their feedback or request gets no answer, or an unsatisfactory one. Each country sets its own procedure, so the statement must name the right national body and link to it. The Web Accessibility Directive requires this link in every statement.
Accessibility statement must list the accessibility features supported
acai-statement-features – WAD
Checks whether the accessibility statement describes the accessibility features the website supports. Examples are zoom levels, changing fonts or colors, keyboard navigation, and support for speech recognition and screen reader software. Knowing what is supported helps users set up the website with the settings and tools they rely on.
Accessibility statement must list accessibility limitations
acai-statement-limitations – WAD
Checks whether the accessibility statement describes the website’s accessibility limitations, such as assistive technologies it does not support. Being open about limitations saves users time and frustration. It also lets them look for another way to get the information before they get stuck.
Accessibility statement must list improvement plans
acai-statement-improvement-plans – WAD
Checks whether the accessibility statement describes plans to improve the website’s accessibility, such as when known problems will be fixed. This shows users that the barriers are being worked on and when to expect a change.
Accessibility statement must contain a way to get offline help
acai-statement-offline-help – WAD
Checks whether the accessibility statement gives a phone number, a postal address or a visiting address where users can get help offline. Some users cannot use the website at all, so an online form or an email address is not enough for them. Offline contact details give them another way to get the information or service they need.
Algorithmic tests (rule based)
Text alternative must be meaningful, not derived from the filename
acai-alt-text-filename – WCAG 1.1.1
Identifies alternative text that appears to be a filename rather than a genuine description of the image. Using a filename as alternative text is a common malpractice in web development, often done to suppress accessibility warnings under the assumption that the filename is a good enough description. It never is. Filenames such as “IMG_2045.jpg” or “header-banner-v2.png” provide no useful information, and because they contain characters such as dashes and underscores as well as file extensions, they cause additional problems for screen reader users who must listen to them being read aloud.
Text that differs from the document language must be declared using the “lang” attribute
acai-document-lang-mismatch – WCAG 3.1.2
Detects when text on a page is written in a different language than the one declared for the document, without the language change being explicitly indicated using the lang attribute. ACAI detects the language of each text block in the document body and compares it to the document’s declared language. Text blocks that differ from the declared language and are not wrapped in an element with the correct lang attribute are flagged as issues.
Value of the “lang” attribute must match the content language
acai-element-lang-mismatch – WCAG 3.1.2
Detects when the declared language of a specific element does not match the actual language of the text within it. When an element uses the lang attribute, the specified language must accurately reflect the content. ACAI detects the language of each text block in the document body and compares it to the declared language of its containing element, flagging mismatches that could cause screen readers to mispronounce the content.
Alternative text must not contain redundant phrasing
acai-alt-text-redundant – WCAG 1.1.1
Detects alternative text that includes phrases such as “image of” or “picture showing”. These phrases are redundant because screen readers already announce images. Including them adds noise, slows navigation, and makes content less efficient for users relying on assistive technology.