How Good Accessibility Practices Help SEO Efforts
Accessibility and SEO go hand in hand. Using semantic HTML, proper alt text, captions, and transcripts makes your site more usable for people with disabilities and easier for search engines to understand. Good accessibility improves user experience, which boosts engagement signals like dwell time and lower bounce rates which can positively impact SEO rankings.
Introduction: Why Accessibility and SEO Go Hand in Hand
When we think about digital accessibility and search engine optimization (SEO), they may seem like competing priorities. Accessibility ensures that people with disabilities can navigate and use a website, while SEO focuses on making a site more discoverable in search engines. However, both share the same goal of creating content that is understandable, usable, and easy to access.
A website built with accessibility in mind often aligns with SEO best practices. Search engines are akin to blind users of your site using a screen reader. They rely on structure, context, and metadata, much like a screen reader does to navigate. If any of these are out of balance, the user and the search engine won't have a great experience, or perhaps one at all. Engaging, well-structured content keeps the bounce rate low, or in plain terms: the rate in which people visit one page during a session and leave without interacting with any other aspect of your site. Similarly, if a website or content isn't easily navigable due to accessibility constraints, those users may leave as well. Hand in hand.
Semantic HTML: Structuring Content for Humans and Search Engines
Semantic HTML is the foundation of both accessibility and SEO. Instead of using generic <div> and <span> tags for everything, semantic tags like <header>, <main>, <article>, <section>, <nav>, and <footer> give meaning to your content. Having worked in many codebases of all sizes throughout the years, it's unfortunately very common to see overuse of <div> and <span>. With some education of why semantic HTML is important, developers and stakeholders will be new converts. The bottom line is affected. Accessible sites are time and time again winners in the SEO space. And frankly, even learning the basics can produce results for your brand.
For accessibility, semantic HTML helps screen readers navigate and announce content in a logical order, improving the experience for people with visual impairments. For SEO, semantic HTML helps search engines understand the hierarchy and context of your content, making it more likely to be indexed correctly and shown to the right audience. We all want our content to be visible and visible to the ideal group of people, right?
Clear heading structures (<h1>, <h2>, <h3>, etc.) are another critical part of this. A properly ordered heading system provides an outline of your page, improving both readability for users and crawlability for search engines.
One thing to keep in mind is that poorly structured HTML and misuse of aria attributes can hurt your SEO efforts, and even lead to a website that is unusable- the opposite of what you are trying to accomplish.
A good example of this that I've seen in the past is a developer creating button-like functionality on a div via <div role='button'> instead of just using the <button> element. Why is this important? For many reasons, and if this is the first you've heard of this best practice, you'll be surprised to know just how useful semantic HTML is at its core. The <button> element in HTML comes natively, out of the box, with keyboard support that lets the user interact with the button in ways they cannot otherwise.
Let's take two elements, <div role='button'>My poor button</div> and <button>My real button</button>
If you have created these in a project, inspect these elements using your favorite browser's inspector. When one has been inspected, go to the console tab and write console.dir($0). This will print the selected element's prototype which will be a huge wall of methods, attributes, and properties that belong to that element by default.
Crucially, the div button has a tabIndex: -1 while the semantic button has a tabIndex: 0. This means the div by default cannot be tabbed to, whereas the semantic button can be. For people who navigate a site with their keyboard, regardless of the presence of a disability or not, the div button requires the developer to attach tabIndex: 0 to it, otherwise keyboard users cannot interact with it at all. Which is hugely problematic.
Just use semantic HTML when in doubt so you don't forget to add prototype features that are required for usability.
Images and Multimedia: Alt Text, Captions, and Transcripts
Images and multimedia elements likewise can be barriers to accessibility if not handled properly. Adding descriptive alt text ensures that users relying on screen readers can understand the meaning or purpose of an image. At the same time, alt text provides search engines with additional context about your content, boosting your SEO performance. Similarly, there is a difference between having an empty alt attribute and omitting the alt altogether.
An alt='' (empty string) signifies to the browser that this image is decorative, which causes screen readers to not read it aloud. Additionally, empty alt text will appear on the screen while the image is loading- which is great for slow connections. A completely missing alt tag on the other hand causes a plethora of problems. It could cause some screen readers to read aloud the actual file name of the image which could be sony-123-xyz.jpg, which is disruptive and confusing at the very least. It provides no meaningful information to SEO crawlers aside from that it is nonsense, which could harm your image SEO. When in doubt, always include an empty alt='' tag at the very least, or ensure you are writing meaningful descriptions for your image, chart, or other visual.
Videos and audio content must include captions and transcripts. Captions help people who are deaf or hard of hearing, while transcripts benefit people who prefer reading or who have difficulty processing audio. Not to mention some people prefer to watch videos on mute on occasion. On the SEO side, transcripts add keyword-rich text that search engines can crawl, giving your multimedia content a better chance of ranking.
User Experience, Accessibility, and SEO Signals
Search engines increasingly prioritize user experience signals, such as page speed, mobile-friendliness, and ease of navigation. These are also key principles of accessibility. A site that’s easy to navigate with a keyboard, has sufficient color contrast, and avoids confusing layouts not only benefits users with disabilities but also improves dwell time (amount of time someone spends on a page before leaving), reduces bounce rates (rate in which a visitor leaves a page without interacting with anything else on your site), and enhances overall engagement, all of which can positively impact SEO rankings.
Accessibility isn’t just about compliance - it’s about providing a better experience for everyone. When users find your site easier to navigate, they stay longer, interact more, and come back again. Search engines notice this behavior and reward it.