Advanced

HTML · Proficient - advanced patterns and performance

• Accessibility: alt, heading hierarchy, and ARIAMaster alternative text, a heading hierarchy screen readers can actually navigate, and ARIA usage limited to cases where native HTML falls short.
• Advanced forms and native validationLeverage required, pattern, inputmode, and the Constraint Validation API for robust forms without any external library.
• Responsive images: srcset, sizes, and pictureServe the right image to the right screen with srcset and sizes, reserve picture for art direction, and master lazy loading.
• Technical SEO: Open Graph and structured dataControl how your pages preview on social networks with Open Graph and aim for rich results with schema.org in JSON-LD.
• Loading performance: defer, async, preload, and prefetchOrder your scripts' execution with defer and async, then steer the network with preload, preconnect, and prefetch.