GSAP Web Animation Skill

Guide to implementing and debugging professional GSAP-based web animations, timelines, and ScrollTrigger interactions.

Views

Uses

Updated

February 3, 2026

Author

MengTo

Skill creator

Source

MengTo/Skills

Added by Meng To

animation motion micro-interactions scroll-effects javascript react performance best-practices

Property	Value
name	gsap
description	Use when you need to add or debug professional web animations with GSAP (timelines, ScrollTrigger, stagger, transforms) in HTML/CSS/JS/React. Includes patterns for smooth motion, performance, and common pitfalls.
keywords	animation, motion, micro-interactions, scroll-effects, javascript, react, performance, best-practices

GSAP (GreenSock) — Web Animation Skill

When to use

High-quality UI/motion design: entrances, micro-interactions, page transitions
Timeline-based sequences (vs. scattered CSS transitions)
Scroll-driven storytelling (with ScrollTrigger)
Complex easing, staggering, orchestration across many elements

Key concepts & APIs

Tweens:
- gsap.to(targets, vars)
- gsap.from(targets, vars)
- gsap.fromTo(targets, fromVars, toVars)
Timelines:
- const tl = gsap.timeline({ defaults, repeat, yoyo, paused })
- Chain:
  tl.to(...).from(...).addLabel('x').add(() => ...)
- Position parameter: absolute 1.2, relative "+=0.5", overlap "-=0.3", label "intro"
Eases: ease: "power2.out", "expo.inOut", "elastic.out(1, 0.3)"
Staggers: stagger: 0.05 or
{ each, from: "start|center|end|random", grid }
Performance-friendly properties:
- Prefer transforms (x, y, scale, rotation) and opacity (autoAlpha)
ScrollTrigger (plugin):
- gsap.registerPlugin(ScrollTrigger)
- Inline:
  gsap.to(".box", { scrollTrigger: ".box", x: 500 })
- Advanced:
  scrollTrigger: { trigger, start, end, scrub, pin, snap, markers }
- Standalone:
  ScrollTrigger.create({ trigger, start, end, onUpdate, onToggle })

Common pitfalls (and fixes)

Animating layout properties (top/left/width/height) → jank
- Use transforms, add will-change: transform, avoid forced reflow.
ScrollTrigger “not firing” due to wrong trigger sizing/overflow containers
- Ensure trigger exists, has height, and check scroll container (nested scrolling needs config).
Not cleaning up in SPA/React
- Use gsap.context() and revert on unmount; kill triggers (
  ScrollTrigger.getAll().forEach(t => t.kill())
  ) if needed.
FOUC / measuring before fonts/images load
- Initialize after layout is stable; run ScrollTrigger.refresh() after images load.

Quick recipes

1) Hero entrance (stagger)

gsap.from(".hero [data-anim]", {
  y: 24,
  autoAlpha: 0,
  duration: 0.8,
  ease: "power2.out",
  stagger: 0.06,
});

2) Sequenced timeline

const tl = gsap.timeline({ defaults: { ease: "power2.out", duration: 0.6 } });
tl.from(".nav", { y: -20, autoAlpha: 0 })
  .from(".hero-title", { y: 30, autoAlpha: 0 }, "-=0.2")
  .from(".hero-cta", { scale: 0.95, autoAlpha: 0 }, "-=0.2");

3) Scroll-scrub pinned section

gsap.registerPlugin(ScrollTrigger);

gsap.timeline({
  scrollTrigger: {
    trigger: ".story",
    start: "top top",
    end: "+=800",
    scrub: 1,
    pin: true,
  },
}).to(".story .panel", { xPercent: -200 });

What to ask the user (if requirements unclear)

Is this a static site or SPA (React/Next/Vue)? Any page transitions?
Do we need scroll-driven sections (pin/scrub/snap)?
Performance constraints (mobile support, reduced motion)?