Definition Of Quality

Browser Support

All functionality must work in any browser listed in the following queries:

• Can I use Service Workers?
• Can I use CSS Grid?

Performance Metrics

Payload Size

• No single asset on a landing page should be larger than 400KB. Use bundlesize to measure this metric.
• Total JavaScript payload should not be larger than 500KB. Check this manually or use either Webpack Bundle Analyzer or bundlesize.

User Responsiveness

• Time to First Contentful Paint must be under 4 seconds. This can be measured using Lighthouse.

UX Requirements

Viewport

Test only against the 360x460 viewport (portrait mode). Landscape mode and desktop mode are not prioritized.

Appearance

Chief call to action must be "above the fold" in the viewport.

Controls

All UI controls must respond to user input unless it is indicated that they are disabled.

Technical Requirements

PWA Checklist

All PWA checklist items must be supported.

• ServiceWorker installs and caches
• manifest.json exists and all assets it lists exist
• All sizes of supported icon exist and are listed in manifest