Making your website accessible to users with disabilities improves user experience for everyone and has direct SEO benefits. Here is where to start.
Why accessibility improvements also improve SEO
Web accessibility and SEO share a deeper connection than most business owners realise. Many of the technical elements that help assistive technologies understand your website, such as alt text on images, proper heading hierarchy, descriptive link text, and semantic HTML structure, are also the same elements that help search engine crawlers understand and index your content. Improving your site for accessibility is one of the few changes that benefits disabled users, all users, and your search rankings simultaneously.
Google has also stated that accessibility improvements can positively influence page experience signals. Sites that are easier to navigate, read, and interact with across all users and devices align more closely with what Google measures through its user experience metrics.
Alt text for images: the accessibility and SEO overlap
Alt text is a brief description of an image that appears when the image fails to load and is read aloud by screen readers for visually impaired users. For SEO, alt text gives Google text-based context about what an image shows, which contributes to image search visibility and helps Google understand the on-page content surrounding the image.
Every informational image on your website should have descriptive alt text that accurately describes what the image shows and includes a relevant keyword where it fits naturally. Decorative images that add no informational value, such as divider lines or background textures, should have an empty alt attribute written as alt= so screen readers skip them rather than announcing a meaningless description.
Colour contrast and text readability for all users
The Web Content Accessibility Guidelines require a minimum contrast ratio of 4.5:1 between text and background for normal text and 3:1 for large text. This requirement exists to ensure that users with low vision or colour blindness can read your content. In practice, it also means your content is easier to read for all users on bright screens, in direct sunlight, or on lower-quality mobile displays.
Use a free tool like the WebAIM Contrast Checker to verify that your colour palette meets minimum contrast requirements. Check your body text, headings, navigation links, button text, and footer text against their backgrounds. If any fail the check, adjust the lightness or darkness of the colour until the contrast ratio is sufficient.
Keyboard navigation and focus indicators
Keyboard navigation allows users who cannot use a mouse, including users with motor disabilities and many assistive technology users, to navigate a website by pressing the Tab key to move between interactive elements. Your website should be fully navigable by keyboard alone. Test this by visiting your homepage and pressing Tab repeatedly to move through every link, button, and form field. Each element should receive a visible focus indicator as you tab through it.
Many websites remove the default browser focus outline in their CSS without replacing it with a custom one, making keyboard navigation invisible and unusable for keyboard-dependent visitors. If you have removed the outline for aesthetic reasons, add a custom focus style using the CSS :focus or :focus-visible selector to make interactive elements clearly identifiable as the cursor moves through them.
Form labels, error messages, and accessible inputs
Every input field on your contact form should have a visible label that is programmatically associated with the field using the HTML for attribute. Placeholder text alone does not serve as an accessible label because it disappears as soon as a user starts typing, which can cause confusion for users who need to check what a field was asking while reviewing their input.
Error messages should be clear, specific, and descriptive. An error message that says invalid email is less helpful than one that says please enter a complete email address such as name@example.com. Both accessibility standards and user experience best practices call for the same thing: give visitors enough information to successfully complete what they started.
Frequently asked questions
Do I need to fully comply with WCAG to avoid legal risk?
Requirements vary by country, industry, and the size of your business. In many jurisdictions, service businesses that fall under disability discrimination legislation are expected to provide accessible web content. Consulting a legal professional in your region is advisable if you have specific compliance concerns.
What is the easiest way to check my website's accessibility?
Run your URL through WAVE at wave.webaim.org for a free automated accessibility scan. Combine this with manual keyboard navigation testing and a contrast checker for a reasonably thorough initial audit.
Need help applying this to your website?
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