Performance

What loads

File	gzip	When
Core	44.6 KB	Always: engine, 27 CSS effects, navigation, autoplay, a11y, smart fit, component, data-*, JSON, styles
Layers	8.8 KB	A slide contains data-in, or imageIn is set
WebGL	7.9 KB	effect is a WebGL effect and the device can use it
Overlays	4.4 KB	overlay is set
Particles	3.8 KB	particles is set
Scroll depth / drive	1.5 KB each	scrollDepth / scrollDrive

The published files are obfuscated (names, strings and property names are encoded). That costs about 16 KB of the core and less than 0.1 ms per frame; nothing changes in the API.

At runtime

• Compositor only. Slides move with transform, opacity, filter and clip-path. Nothing triggers layout while sliding.
• requestAnimationFrame runs only while something moves. An idle slider costs nothing.
• Off screen = paused. Autoplay, WebGL, particles, layer loops and background videos stop when the slider leaves the viewport or the tab is hidden.
• One measurement per resize, batched with ResizeObserver and a frame.
• Textures are cached (8 per slider, least recently used evicted); the WebGL context is released on destroy().

Core Web Vitals

• CLS: the height is computed before the first paint of the slides. For a hero above the fold, give the first image width / height attributes or set aspect so the space is reserved before the image loads.
• LCP: load the first slide's image eagerly (fetchpriority="high"); use data-src for the others.
• INP: input handlers do no layout work; the first visual response to a drag happens in the same frame.

Checklist

• Serve images at the size they are shown: srcset + sizes="100vw" for full-width heroes.
• Prefer one WebGL slider per page.
• Use lazy (default) with preload: 1.