| name | performance-budget-design |
| description | Use when designing for performance. Covers Core Web Vitals, the design decisions that affect performance (web fonts, images, JS), and the budget framework.
|
Performance Budget Design
Performance is a design decision. A beautiful page that takes 8 seconds to load is broken.
Core Web Vitals
LCP (Largest Contentful Paint) < 2.5s. FID/INP (Input) < 200ms. CLS (Cumulative Layout Shift) < 0.1.
Performance budget
Total page weight target (e.g., < 1MB). JS budget (< 200kB). Image budget. Track per-page.
Design decisions that hurt
Web fonts (200-500kB). Hero videos. Unoptimized images. Heavy animations. Third-party scripts (analytics, chat widgets).
Design decisions that help
System fonts. Static hero. Responsive images. CSS animations over JS. Lazy-load below fold.
Common mistakes
Designing in Figma, never opening DevTools. Web fonts blocking render. Hero images 3MB. Lighthouse scores 50/100 ignored.
Where this fits in X3 Compass
Applied across the X3 Compass design system.