What SEO Can Learn from Web Accessibility
As an SEO Specialist and a web accessibility advocate, I often notice something interesting: many best practices in accessibility also benefit SEO — but they’re rarely discussed together.
SEO is often seen as a numbers game: rankings, traffic, CTRs. Accessibility is sometimes treated as a checkbox or a developer-only issue, if we’re lucky. But they’re both about something bigger — helping people use the web more effectively. One helps users find the content; the other helps all users interact with it.
Let’s take a closer look at what SEO can learn from the principles of accessibility — and how fully embracing a design that prioritizes accessibility can significantly improve not just search engine rankings, but also overall usability, audience reach, and long-term performance.
SEO and Accessibility Overlap More than You Think
If an assistive device (like a screenreader or a keyboard-only browsing) is able to fully use a website, then Google (and others) can effectively crawl your site.
Heading Structure
Accessibility: Screen readers rely on logical heading hierarchies to help users navigate content.
SEO: Search engines also use headings to understand page structure and context. Content hierarchy improves crawling and relevance.
Stick to one h1 per page, as it’s a best practice for SEO. Avoid skipping heading levels - don’t skip from h2 to h4.
Alt Text for Images
Accessibility: Describes images for users who can’t see them
SEO: Supports image indexing, especially when descriptive and relevant.
Good alt text doesn’t mean keyword stuffing — it means describing the image clearly in context. A good alt text can also help when an image is not loading - users can gather from the clues if it’s an important image (like a graph) or just a helpful image (for easier understanding of the subject).
Semantic HTML
Accessibility: Tags like <nav>, <main>, <article>, <section> offer important context to assistive technologies
SEO: These same tags help search engines by giving crawlers extra signals about content priority and structure
Don’t rely only on <div> and <span>, as easy as that is with website builders or that blog section that your dev gave access to for your team - use semantic tags wherever possible.
Descriptive Anchor Text
Accessibility: Generic phrases like “click here” are confusing for screen reader users, as they’re not sure what page they’re going to without having to backtrack.
SEO: Descriptive anchor text improves contextual linking and keyword relevance
Use text that tells the user (and Google) where they’re going. This will also help strenghten your keyword pool - use secondary keywords for some of these.
Colour Contrast and Readability
Accessibility: Ensures all users — especially those with visual impairments — can read content
SEO: Hard-to-read text = higher bounce rates = poor UX signals = potential ranking drops.
Having content that is easy to read should improve your bounce rate and dwell time, as users can see. Having red text on a dark green background, for example, is harder, if not impossible to read. Think of adding an extra colour for contrast to your branding. You don’t have to change company assets, just change some accent colours or add a text background.
How Accessibility Boosts SEO
Sometimes the best SEO improvements come from solving accessibility problems — even if no one calls them that at the time.
Fashion Retailer: When Everything’s an <h2>
I once worked with a luxury fashion retailer at my agency job whose site used <h2> tags for everything — product titles, filter names, descriptions, you name it.
From an accessibility perspective, this made the page unreadable for screen readers. There was no logical structure, no way to navigate by section, and no semantic hierarchy.
From an SEO standpoint? Google had no idea what the most important content was, and was ranking pages for the wrong keywords, generic pages were showing up for branding queries, and there was a lot of fluctutation in the pages that ranked, clearly signalling Google’s confusion.
What I proposed we do:
Cleaned up the HTML so that the category name was the <h1>
Assigned filters to a <button> or <label> element, not headings - this unfortunately had not been implemented before my departure, but the <h2> was changed to a <h4>
Used <h2> for major sections and <h3> for subcategories
Added meaningful, unique, indexable category descriptions
Implemented canonical tags to handle duplicate filter URLs
The SERPS settled, the right pages were starting to rank in the top 10 for the proper keywords, even going into the top 5. We continued tweaking the content by adding secondary keywords, proper interlinking of pages, boosts in the menu section.
Why SEOs Should Care (Even If It’s Not in the Brief)
Many SEO projects focus on short-term wins: rankings, quick technical fixes, scalable metadata. Accessibility isn’t always part of that scope. But here’s why it should be:
It’s ethical. The web should work for everyone.
It’s strategic. Google increasingly rewards usability and intent-matching. How long have we seen UX in reports? Accessibility is part of “user experience”.
It’s long-term. Accessible websites tend to be faster, clearer, and easier to maintain.
It’s good branding. Inclusive sites reflect modern, responsible digital teams.
It’s a legal requirement. You think you won’t be affected until you are. At a previous job, where we mainly sold watches online, we lost a web accessibility case and had to rework the site in one month.
And from a purely selfish perspective? Most SEOs aren’t thinking about accessibility — so this gives you a head start.