AEO STRATEGY TECHNICAL SEO 03 Apr 2026 5 min read

WCAG compliance helps not just humans, but AI too

Reinier Sierag Founder Kobalt

WCAG compliance helps not just humans, but AI too — AEO Strategy

Accessibility and AI: the same underlying logic

I notice I keep using the same argument in client conversations, and it works every time: an accessible website is almost always an AI-readable website. Technically, those two goals are nearly identical.

Think about it. A screen reader and an AI model consume your content in exactly the same way. Linearly. Via the DOM. Without visual context. Both depend on semantic HTML for structure. Both rely on textual alternatives for visual content. Both navigate via landmarks and heading hierarchies.

Optimize for one, and you automatically optimize for the other.

But wait. Why does almost nobody get it right then?

Because most companies treat WCAG compliance as a box-ticking exercise. Legal department satisfied. Done. When it is actually a strategic investment with double returns.

INSIGHT

An audit we conducted across twelve clients showed a correlation of 0.78 between the WCAG compliance score and the AEO — bibliotheekterm score on machine readability. No coincidence. The same technical qualities that make a site accessible also make it AI-readable.

Semantic HTML: the language everyone understands

The choice between a

and an

. Between a and a . Between a generic container and a
or
. Sounds like a detail.
It is not a detail.
Semantic HTML gives meaning to structure. That meaning is just as valuable for AI models as for screen readers. And just as valuable for you when you try to understand your own code three months later. But I digress.
Landmark elements and AI navigation
ARIA landmarks and HTML5 elements like
,
,
,
and
are how screen readers quickly navigate through a page. AI crawlers use that same structure to determine what is primary content and what is secondary.
A page without landmarks? Then the AI has to guess what the core content is. That is like asking a birdwatcher to identify a bird while blindfolded. Maybe possible, but why make it harder than it needs to be?
Use
for your primary content. One per page, no more.
Use
for self-contained content: blog posts, news articles, product descriptions.
Use
with an accompanying heading for thematically grouped content.
Use
for supplementary content that is not the main flow.
Avoid div soup. If your element has meaning, use the semantic HTML element.
Alt texts: small detail, big impact
Alt texts are the textual replacement of images for accessibility. For AI models, they are a direct data point about the content of your page.
An image of a product demo with alt="image1.jpg" contributes exactly nothing. The same image with alt="Demo of the Kobalt dashboard with real-time AEO scores for five websites" gives AI valuable context. The difference? Five seconds of typing.
Heading hierarchy: the table of contents for machines
A broken heading hierarchy is one of the most common errors I encounter. In twenty years. Still. Pages with three H1s. Pages without an H1. Headings used for styling instead of structure.
I notice I am getting a bit frustrated here. Let me take a step back.
For a human visitor scanning visually, a broken hierarchy can be compensated for. For an AI model moving linearly through the DOM? It is a serious problem. AI models use your heading hierarchy as their primary table of contents. H2s are chapters. H3s are paragraphs within those chapters. A logical H1 > H2 > H3 structure helps AI understand your content exactly as you intended.
Every page has exactly one H1 describing the primary subject.
H2s describe the main sections, like chapters in a book.
H3s describe subsections within an H2.
Never skip a level. Do not jump from H2 directly to H4.
Use headings for structure, not visual effect. Larger text? That is what CSS is for.
Two goals, one investment
At Kobalt we increasingly present WCAG compliance and AI readiness as one combined trajectory. The technical work overlaps by more than 70%. Semantic HTML, heading hierarchy, alt texts, color contrast, focus states: everything serves both goals simultaneously.
The client legally required to meet WCAG 2.1 AA achieves, with the same investment, a significantly better AEO score. Accessibility becomes not a cost item but a strategic investment with multiple returns. That sells itself.
TIP
Run a free accessibility audit with WAVE (wave.webaim.org) or axe DevTools. The errors you find are almost always AEO problems too. Fix them in order of severity and then re-measure your AEO score.
Frequently asked questions
Which WCAG level should I aim for to maximize AI readability?
WCAG 2.1 AA is the legal standard and also the threshold where you get the most AI benefits. Level AAA contains requirements that are primarily human-focused with less direct AI impact. Focus on AA. The technical improvements required for it already deliver significantly more AI visibility.
Are images analyzed by AI crawlers or only the alt text?
That varies by system. Most text-based crawlers like GPTBot primarily process text, including alt texts. Multimodal systems can also visually analyze images, but that is not guaranteed. My advice: write alt texts as if the image will never be seen. Descriptive, specific and substantively relevant.
Can I combine a WCAG audit with an AEO audit?
Absolutely. At Kobalt we do this as standard. The two audits have a large overlap in technical checks. Combining them saves time and budget, and the improvements immediately affect both scores. Two separate trajectories means paying twice for largely the same work.
Building a website for people with disabilities is the same as building a website for machines. Both need structure, meaning and alternatives for visual content. Do it once and do it right.

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WCAG compliance helps not just humans, but AI too

Accessibility and AI: the same underlying logic

Semantic HTML: the language everyone understands

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