Sigmoid 1.0.0 is out: @sweberdev/sigmoid, -react, -vue and -svelte, all MIT. It is the release candidate 0.9.0 without changes to the API.
What Sigmoid is
Scroll motion without the JavaScript tax. Reveals, parallax, scroll-linked progress and counters run on native CSS scroll timelines where the browser has them, and on one passive scroll listener where it does not. Spring and S-curve easings are shipped as CSS linear(). Reduced motion is respected by default. A reveal is about 3 kB min+gzip, everything about 5 kB.
<link rel="stylesheet" href="sigmoid.css" />
<h2 data-sigmoid="fade-up">Our work</h2>
What is in 1.0
- Presets,
reveal,parallax,scrubwith ranges,track,story,splitText, counters and pinned sections, on the block and the inline axis, in page and scroll containers, left to right and right to left. - Linked animations: one element drives another through named timelines.
- Adapters for React, Vue and Svelte, a Tailwind v4 theme and an Astro guide.
- A curve editor and a live demo of every feature.
- A benchmark against GSAP ScrollTrigger, Motion and AOS, and migration guides.
- Tests: 62 unit tests and real-browser tests in Chromium, Firefox and WebKit, native and fallback compared.
What 1.0 promises
The stability policy: patch releases fix bugs, minor releases add features without breaking anything, only a major release may break, and deprecations stay for at least one minor version and six months. Tests fail when an export disappears.
Where it is honest
With hundreds of elements animating at once, Chromium's native path costs more main-thread time than GSAP in our headless benchmark. The benchmark page says so; for very long lists, reveal only what is near the viewport. Inside CSS zoom, the fallback measures live instead of from its cache.
Install
npm install @sweberdev/sigmoid
Thanks to everyone who tried the release candidates. Feedback and issues are welcome at Weber-Development/sigmoid.