View Transitions API

• Same-document: SPA-like transitions without reloading the page
• Cross-document: transitions between MPA pages (Chrome 126+)
• CSS: ::view-transition-old(*) / ::view-transition-new(*)
• Customise: view-transition-name per element
• Fallback: no support — instant transition without animation

// Plain JS — SPA page switch
function navigate(url) {
  if (!document.startViewTransition) return render(url);
  document.startViewTransition(() => render(url));
}

// CSS custom animation
@keyframes fade-in { from { opacity: 0; } }
::view-transition-new(root) {
  animation: fade-in 0.3s ease;
}

• Streaming SSR
• Edge Runtime