Why do single-page applications (SPAs) create accessibility challenges?

Single-page applications (SPAs) create accessibility challenges primarily because they often load content dynamically through AJAX without triggering a full page refresh. This means that traditional screen readers may not be aware of changes occurring on the page, as they typically announce updates only on full page navigations. When new content is added or existing content is modified via JavaScript, a screen reader might not automatically inform users that something has changed, thus maintaining an outdated view of the page for the user.

This can lead to confusion and make it difficult for users who rely on assistive technologies to understand the current context of the application. In contrast, a more conventional web application that reloads the entire page when content changes tends to ensure that screen readers announce the new content correctly, providing a more seamless experience for users with disabilities.