HTTP Archive Report Finds Web Accessibility Still Lags
The latest HTTP Archive Tech Report, analyzing thousands of websites, found that many still underperform on accessibility standards. The report also analyzed median Lighthouse scores for Core Web Vitals (LCP, INP, CLS), reinforcing that performance remains a key differentiator for user retention and search ranking.
- WebAIM's 2024 analysis of the top one million homepages revealed that 95.9% had detectable Web Content Accessibility Guidelines (WCAG) failures, a slight improvement from 96.3% in 2023. The most common failure was low-contrast text, present on 81% of homepages. Other frequent issues included missing alternative text for images (54.5% of sites), missing form input labels (48.6%), and empty hyperlinks (44.6%). - The Web Content Accessibility Guidelines (WCAG) are the global standard for web accessibility, built on four main principles known as POUR: Perceivable, Operable, Understandable, and Robust. These guidelines have different conformance levels: A (minimum), AA (mid-range and widely considered the legal standard), and AAA (highest). - As of March 2024, Google's Core Web Vitals, which are a factor in search rankings, include Interaction to Next Paint (INP), replacing First Input Delay (FID). The key benchmarks for a good user experience are an LCP (Largest Contentful Paint) of 2.5 seconds or less, an INP of 200 milliseconds or less, and a CLS (Cumulative Layout Shift) score of 0.1 or less. - Data from early 2026 shows that 43% of websites still fail the INP threshold, making it the most commonly failed Core Web Vital. Optimizing for INP often requires significant changes to JavaScript architecture to break up long tasks and yield to the main thread during user interactions. - Website performance has a direct impact on user retention, with studies showing that 53% of mobile users will abandon a site if it takes longer than three seconds to load. A one-second delay in page load time can lead to a 7% reduction in conversions. - Automated tools like Lighthouse can help identify many accessibility issues, but manual testing is crucial. One 2024 analysis found that while 16% of accessibility problems could be found with automated tools, 84% required manual identification by a human tester. - Common accessibility failures that developers should check for include improper heading structure (using styled text instead of `<h1>` - `<h6>` tags), keyboard focus not being managed correctly in components like modal dialogs, and interactive elements that are not keyboard accessible. - The median Lighthouse accessibility score has shown slow improvement over the years, rising from 80% in 2020 to 85% in 2025. Despite this, only about 30% of mobile sites in 2025 met the minimum color contrast requirements.
