Core Web Vitals for 3D-heavy websites
You can ship a cinematic 3D homepage and still pass Core Web Vitals, if you treat performance as part of the design.
Core Web Vitals are Google's field metrics for loading, responsiveness and visual stability. The thresholds for a good experience are: Largest Contentful Paint at 2.5 seconds or less, Interaction to Next Paint at 200 milliseconds or less, and Cumulative Layout Shift at 0.1 or less.
Paint something useful first
Render the headline and primary call to action as plain HTML so the page is meaningful immediately. Load the 3D scene afterwards, with a lightweight placeholder where it will appear.
Budget the 3D
- Prefer generated or compressed geometry over heavy models.
- Reuse materials and use instancing for repeated objects.
- Cap the device pixel ratio so high-density phones do not render four times the pixels.
- Pause rendering when the canvas is off screen.
Protect interaction
Keep main-thread work small so taps and scrolls respond quickly. Run animation on the compositor where possible and avoid blocking scripts during load.
Avoid layout shift
Reserve space for the canvas and for any late-loading fonts or images, so nothing jumps while the page settles.
Measure on real devices
Test on a mid-range phone and a throttled connection, and watch field data once the site is live. A 3D homepage that passes there is genuinely fast, not just fast on a developer's laptop.