BjornMelin GSAP Plugins
When to Use This Skill
Apply when using or reviewing code that uses GSAP plugins: registering plugins, scroll-to, flip/FLIP animations, draggable elements, SVG (DrawSVG, MorphSVG, MotionPath), text (SplitText, ScrambleText), physics, easing plugins (CustomEase, EasePack, CustomWiggle, CustomBounce), or GSDevTools. ScrollTrigger has its own skill (gsap-scrolltrigger).
Related skills: For core tweens use gsap-core; for ScrollTrigger use gsap-scrolltrigger; for React use gsap-react.
Licensing & Install (important)
Every GSAP plugin is free, including for commercial use. Since Webflow's acquisition of GSAP, Club GSAP is no longer a paid tier and no plugin requires a membership, license key, or auth token — this includes formerly Club-only plugins (SplitText, MorphSVG, etc.).
- ✅ Install everything from the public
gsapnpm package:npm install gsap. All plugins are included — import them asgsap/SplitText,gsap/MorphSVGPlugin, etc. - ❌ Do not generate an
.npmrcwith a GreenSock auth token, suggest the privatenpm.greensock.comregistry, or tell users to sign up for Club GSAP to access a plugin. Those instructions are outdated.
Registering Plugins
Register each plugin once so GSAP (and bundlers) know to include it. Use gsap.registerPlugin() with every plugin used in the project:
import gsap from "gsap";
import { ScrollToPlugin } from "gsap/ScrollToPlugin";
import { Flip } from "gsap/Flip";
import { Draggable } from "gsap/Draggable";
gsap.registerPlugin(ScrollToPlugin, Flip, Draggable);
- ✅ Register before using the plugin in any tween or API call.
- ✅ In React, register at top level or once in the app (e.g. before first useGSAP); do not register inside a component that re-renders. useGSAP is a plugin that needs to be registered before use.
Scroll
ScrollToPlugin
Animates scroll position (window or a scrollable element). Use for “scroll to element” or “scroll to position” without ScrollTrigger.
gsap.registerPlugin(ScrollToPlugin);
gsap.to(window, { duration: 1, scrollTo: { y: 500 } });
gsap.to(window, { duration: 1, scrollTo: { y: "#section", offsetY: 50 } });
gsap.to(scrollContainer, { duration: 1, scrollTo: { x: "max" } });
ScrollToPlugin — key config (scrollTo object):
| Option | Description |
|---|---|
x, y |
Target scroll position (number), or "max" for maximum |
element |
Selector or element to scroll to (for scroll-into-view) |
offsetX, offsetY |
Offset in pixels from the target position |
ScrollSmoother
Smooth scroll wrapper (smooths native scroll). Requires ScrollTrigger and a specific DOM structure (content wrapper + smooth wrapper). Use when smooth, momentum-style scroll is needed. See GSAP docs for setup; register after ScrollTrigger. DOM structure would look like:
<body>
<div id="smooth-wrapper">
<div id="smooth-content">
<!--- ALL YOUR CONTENT HERE --->
</div>
</div>
<!-- position: fixed elements can go outside --->
</body>
DOM / UI
Flip
Capture state with Flip.getState(), then apply changes (e.g. layout or class changes), then use Flip.from() to animate from the previous state to the new state (FLIP: First, Last, Invert, Play). Use when animating between two layout states (lists, grids, expanded/collapsed).
gsap.registerPlugin(Flip);
const state = Flip.getState(".item");
// change DOM (reorder, add/remove, change classes)
Flip.from(state, { duration: 0.5, ease: "power2.inOut" });
Flip — key config (Flip.from vars):
| Option | Description |
|---|---|
absolute |
Use position: absolute during the flip (default: false) |
nested |
When true, only the first level of children is measured (better for nested transforms) |
scale |
When true, scale elements to fit (avoids stretch); default true |
simple |
When true, only position/scale are animated (faster, less accurate) |
duration, ease |
Standard tween options |
More information
https://gsap.com/docs/v3/Plugins/Flip
Draggable
Makes elements draggable, spinnable, or throwable with mouse/touch. Use for sliders, cards, reorderable lists, or any drag interaction.
gsap.registerPlugin(Draggable, InertiaPlugin);
Draggable.create(".box", { type: "x,y", bounds: "#container", inertia: true });
Draggable.create(".knob", { type: "rotation" });
Draggable — key config options:
| Option | Description |
|---|---|
type |
"x", "y", "x,y", "rotation", "scroll" |
bounds |
Element, selector, or { minX, maxX, minY, maxY } to constrain drag |
inertia |
true to enable throw/momentum (requires InertiaPlugin) |
edgeResistance |
0–1; resistance when dragging past bounds |
cursor |
CSS cursor during drag |
onDragStart, onDrag, onDragEnd |
Callbacks; receive event and target |
onThrowUpdate, onThrowComplete |
Callbacks when inertia is active |
Inertia (InertiaPlugin)
Works with Draggable for momentum after release, or track the inertia/velocity of any property of any object so that it can then seamlessly glide to a stop using a simple tween. Register with Draggable when using inertia: true:
gsap.registerPlugin(Draggable, InertiaPlugin);
Draggable.create(".box", { type: "x,y", inertia: true });
Or track velocity of a property:
InertiaPlugin.track(".box", "x");
Then use "auto" to continue the current velocity and glide to a stop:
gsap.to(obj, { inertia: { x: "auto" } });
Observer
Normalizes pointer and scroll input across devices. Use for swipe, scroll direction, or custom gesture logic without tying directly to scroll position like ScrollTrigger.
gsap.registerPlugin(Observer);
Observer.create({
target: "#area",
onUp: () => {},
onDown: () => {},
onLeft: () => {},
onRight: () => {},
tolerance: 10
});
Observer — key config options:
| Option | Description |
|---|---|
target |
Element or selector to observe |
onUp, onDown, onLeft, onRight |
Callbacks when swipe/scroll passes tolerance in that direction |
tolerance |
Pixels before direction is detected; default 10 |
type |
"touch", "pointer", or "wheel" (default: "touch,pointer") |
Text
SplitText
Splits an element’s text into characters, words, and/or lines (each in its own element) for staggered or per-unit animation. Use when animating text character-by-character, word-by-word, or line-by-line. Returns an instance with chars, words, lines (and masks when mask is set). Restore original markup with revert() or let gsap.context() revert. Integrates with gsap.context(), matchMedia(), and useGSAP(). API: SplitText.create(target, vars) (target = selector, element, or array).
gsap.registerPlugin(SplitText);
const split = SplitText.create(".heading", { type: "words, chars" });
gsap.from(split.chars, { opacity: 0, y: 20, stagger: 0.03, duration: 0.4 });
// later: split.revert() or let gsap.context() cleanup revert
With onSplit() (v3.13.0+), animations run on each split and on re-split when autoSplit is used; returning a tween/timeline from onSplit() lets SplitText clean up and sync progress on re-split:
SplitText.create(".split", {
type: "lines",
autoSplit: true,
onSplit(self) {
return gsap.from(self.lines, { y: 100, opacity: 0, stagger: 0.05, duration: 0.5 });
}
});
SplitText — key config (SplitText.create vars):
| Option | Description |
|---|---|
| type | Comma-separated: "chars", "words", "lines". Default "chars,words,lines". Only split what is needed (e.g. "words, chars" if not using lines) for performance. Avoid chars-only without words/lines or use smartWrap: true to prevent odd line breaks. |
| charsClass, wordsClass, linesClass | CSS class on each split element. Append "++" to add an incremented class (e.g. linesClass: "line++" → line1, line2, …). |
| aria | "auto" (default), "hidden", or "none". Accessibility: "auto" adds aria-label on the split element and aria-hidden on line/word/char elements so screen readers read the label; "hidden" hides all from readers; "none" leaves aria unchanged. Use "none" plus a screen-reader-only duplicate if nested links/semantics must be exposed. |
| autoSplit | When true, reverts and re-splits when fonts finish loading or when the element width changes (and lines are split), avoiding wrong line breaks. Animations must be created inside onSplit() so they target the newly split elements; return the animation from onSplit() for automatic cleanup and time-sync on re-split. |
| onSplit(self) | Callback when split completes (and on each re-split if autoSplit is true). Receives the SplitText instance. Returning a GSAP tween or timeline enables automatic revert/sync of that animation when re-splitting. |
| mask | "lines", "words", or "chars". Wraps each unit in an extra element with overflow: clip for mask/reveal effects. Only one type; access wrappers on the instance’s masks array (or use class -mask if a class is set). |
| tag | Wrapper element tag; default "div". Use "span" for inline (note: transforms like rotation/scale may not render on inline elements in some browsers). |
| deepSlice | When true (default), nested elements (e.g. <strong>) that span multiple lines are subdivided so lines don’t stretch vertically. Only applies when splitting lines. |
| ignore | Selector or element(s) to leave unsplit (e.g. ignore: "sup"). |
| smartWrap | When splitting chars only, wraps words in a white-space: nowrap span to avoid mid-word line breaks. Ignored if words or lines are split. Default false. |
| wordDelimiter | Word boundary: string (default " "), RegExp, or { delimiter: RegExp, replaceWith: string } for custom splitting (e.g. zero-width joiner for hashtags, or non-Latin). |
| prepareText(text, parent) | Function that receives raw text and parent element; return modified text before splitting (e.g. to insert break markers for languages without spaces). |
| propIndex | When true, adds a CSS variable with index on each split element (e.g. --word: 1, --char: 2). |
| reduceWhiteSpace | Collapse consecutive spaces; default true. From v3.13.0 also honors line breaks and can insert <br> for <pre>. |
| onRevert | Callback when the instance is reverted. |
Tips: Split only what is animated (e.g. skip chars if only animating words). For custom fonts, split after they load (e.g. document.fonts.ready.then(...)) or use autoSplit: true with onSplit(). To avoid kerning shift when splitting chars, use CSS font-kerning: none; text-rendering: optimizeSpeed;. Avoid text-wrap: balance; it can interfere with splitting. SplitText does not support SVG <text>.
Learn more: SplitText
ScrambleText
Animates text with a scramble/glitch effect. Use when revealing or transitioning text with a scramble.
gsap.registerPlugin(ScrambleTextPlugin);
gsap.to(".text", {
duration: 1,
scrambleText: { text: "New message", chars: "01", revealDelay: 0.5 }
});
SVG
DrawSVG (DrawSVGPlugin)
Reveals or hides the stroke of SVG elements by animating stroke-dashoffset / stroke-dasharray. Works on <path>, <line>, <polyline>, <polygon>, <rect>, <ellipse>. Use when “drawing” or “erasing” strokes.
drawSVG value: Describes the visible segment of the stroke along the path (start and end positions), not “animate from A to B over time.” Format: "start end" in percent or length. Examples: "0% 100%" = full stroke; "20% 80%" = stroke only between 20% and 80% (gaps at both ends). The tween animates from the element’s current segment to the target segment — e.g. gsap.to("#path", { drawSVG: "0% 100%" }) goes from whatever it is now to full stroke. Single value (e.g. 0, "100%") means start is 0: "100%" is equivalent to "0% 100%".
Required: The element must have a visible stroke — set stroke and stroke-width in CSS or as SVG attributes; otherwise nothing is drawn.
gsap.registerPlugin(DrawSVGPlugin);
// draw from nothing to full stroke
gsap.from("#path", { duration: 1, drawSVG: 0 });
// or explicit segment: from 0–0 to 0–100%
gsap.fromTo("#path", { drawSVG: "0% 0%" }, { drawSVG: "0% 100%", duration: 1 });
// stroke only in the middle (gaps at ends)
gsap.to("#path", { duration: 1, drawSVG: "20% 80%" });
Caveats: Only affects stroke (not fill). Prefer single-segment <path> elements; multi-segment paths can render oddly in some browsers. Contents of <use> cannot be visually changed. DrawSVGPlugin.getLength(element) and DrawSVGPlugin.getPosition(element) return stroke length and current position.
Learn more: DrawSVG
MorphSVG (MorphSVGPlugin)
Morphs one SVG shape into another by animating the d attribute (path data). Start and end shapes do not need the same number of points — MorphSVG converts to cubic beziers and adds points as needed. Use for icon-to-icon morphs, shape transitions, or path-based animations. Works on <path>, <polyline>, and <polygon>; <circle>, <rect>, <ellipse>, and <line> are converted internally or via MorphSVGPlugin.convertToPath(selector | element) (replaces the element in the DOM with a <path>).
morphSVG value: Can be a selector (e.g. "#lightning"), an element, raw path data (e.g. "M47.1,0.8 73.3,0.8..."), or for polygon/polyline a points string (e.g. "240,220 240,70 70,70 70,220"). For full config use the object form with shape as the only required property.
gsap.registerPlugin(MorphSVGPlugin);
// convert primitives to path first if needed:
MorphSVGPlugin.convertToPath("circle, rect, ellipse, line");
gsap.to("#diamond", { duration: 1, morphSVG: "#lightning", ease: "power2.inOut" });
// object form:
gsap.to("#diamond", {
duration: 1,
morphSVG: { shape: "#lightning", type: "rotational", shapeIndex: 2 }
});
MorphSVG — key config (morphSVG object):
| Option | Description |
|---|---|
| shape | (Required.) Target shape: selector, element, or raw path string. |
| type | "linear" (default) or "rotational". Rotational uses angle/length interpolation and can avoid kinks mid-morph; try it when linear looks wrong. |
| map | How segments are matched: "size" (default), "position", or "complexity". Use when start/end segments don’t line up; if none work, split into multiple paths and morph each. |
| shapeIndex | Offsets which point in the start path maps to the first point in the end path (avoids shape “crossing over” or inverting). Number for single-segment paths; array for multi-segment (e.g. [5, 1, -8]). Negative reverses that segment. Use shapeIndex: "log" once to log the auto-calculated value, then paste the number/array into the tween. findShapeIndex(start, end) (separate utility) provides an interactive UI to find a good value. Only applies to closed paths. |
| smooth | (v3.14+). Adds smoothing points. Number (e.g. 80), "auto", or object: { points: 40 | "auto", redraw: true | false, persist: true | false }. redraw: false keeps original anchors (perfect fidelity, less even spacing). persist: false removes added points when the tween ends. Use when the default morph looks jagged or unnatural. |
| curveMode | Boolean (v3.14+). Interpolates control-handle angle/length instead of raw x/y to avoid kinks on curves. Try if a morph has a mid-morph kink. |
| origin | Rotation origin for type: "rotational". String: "50% 50%" (default) or "20% 60%, 35% 90%" for different start/end origins. |
| precision | Decimal places for output path data; default 2. |
| precompile | Array of precomputed path strings (or use precompile: "log" once, copy from console). Skips expensive startup calculations; use for very complex morphs. Only for <path> (convert polygon/polyline first). |
| render | Function(rawPath, target) called each update — e.g. draw to canvas. RawPath is an array of segments (each segment = array of alternating x,y cubic bezier coords). |
| updateTarget | When using render (e.g. canvas-only), set updateTarget: false so the original <path> is not updated. MorphSVGPlugin.defaultUpdateTarget sets default. |
Utilities: MorphSVGPlugin.convertToPath(selector | element) converts circle/rect/ellipse/line/polygon/polyline to <path> in the DOM. MorphSVGPlugin.rawPathToString(rawPath) and stringToRawPath(d) convert between path strings and raw arrays. The plugin stores the original d on the target (e.g. for tweening back: morphSVG: "#originalId" or the same element).
Tips: For twisted or inverted morphs, set shapeIndex (use "log" or findShapeIndex()). For multi-segment paths, shapeIndex is an array (one value per segment). Precompile only when the first frame is slow; it does not fix jank during the tween (simplify the SVG or reduce size if needed).
Learn more: MorphSVG
MotionPath (MotionPathPlugin)
Animates an element along an SVG path. Use when moving an object along a path (e.g. a curve or custom route).
gsap.registerPlugin(MotionPathPlugin);
gsap.to(".dot", {
duration: 2,
motionPath: { path: "#path", align: "#path", alignOrigin: [0.5, 0.5] }
});
MotionPath — key config (motionPath object):
| Option | Description |
|---|---|
path |
SVG path element, selector, or path data string |
align |
Path element or selector to align the target to |
alignOrigin |
[x, y] origin (0–1); default [0.5, 0.5] |
autoRotate |
Rotate element to follow path tangent |
curviness |
0–2; path smoothing |
MotionPathHelper
Visual editor for MotionPath (alignment, offset). Use during development to tune path alignment.
gsap.registerPlugin(MotionPathPlugin, MotionPathHelper);
const helper = MotionPathHelper.create(".dot", {
path: "#path",
end: 0.5
});
// adjust in UI, then use helper.path or helper.getProgress() in your animation
Easing
CustomEase
Custom easing curves (cubic-bezier or SVG path). Use when a built-in ease is not enough. Basic usage is covered in gsap-core; register when using:
gsap.registerPlugin(CustomEase);
const ease = CustomEase.create("name", ".17,.67,.83,.67");
gsap.to(".el", { x: 100, ease: ease, duration: 1 });
EasePack
Adds more named eases (e.g. SlowMo, RoughEase, ExpoScaleEase). Register and use the ease names in tweens.
CustomWiggle
Wiggle/shake easing. Use when a value should “wiggle” (multiple oscillations).
CustomBounce
Bounce-style easing with configurable strength.
Physics
Physics2D (Physics2DPlugin)
2D physics (velocity, angle, gravity). Use when animating with simple physics (e.g. projectiles, bouncing).
gsap.registerPlugin(Physics2DPlugin);
gsap.to(".ball", {
duration: 2,
physics2D: {
velocity: 250,
angle: 80,
gravity: 500
}
});
PhysicsProps (PhysicsPropsPlugin)
Applies physics to property values. Use for physics-driven property animation.
gsap.registerPlugin(PhysicsPropsPlugin);
gsap.to(".obj", {
duration: 2,
physicsProps: {
x: { velocity: 100, end: 300 },
y: { velocity: -50, acceleration: 200 }
}
});
Development
GSDevTools
UI for scrubbing timelines, toggling animations, and debugging. Use during development only; do not ship. Register and create an instance with a timeline reference.
gsap.registerPlugin(GSDevTools);
GSDevTools.create({ animation: tl });
Other
Pixi (PixiPlugin)
Integrates GSAP with PixiJS for animating Pixi display objects. Register when animating Pixi objects with GSAP.
gsap.registerPlugin(PixiPlugin);
const sprite = new PIXI.Sprite(texture);
gsap.to(sprite, { pixi: { x: 200, y: 100, scale: 1.5 }, duration: 1 });
Best practices
- ✅ Register every plugin used with gsap.registerPlugin() before first use.
- ✅ Use Flip.getState() → DOM change → Flip.from() for layout transitions; use Draggable + InertiaPlugin for drag with momentum.
- ✅ Revert plugin instances (e.g.
SplitTextInstance.revert()) when components unmount or elements are removed.
Do Not
- ❌ Use a plugin in a tween or API without registering it first (gsap.registerPlugin()).
- ❌ Ship GSDevTools or development-only plugins to production.
Learn More
https://gsap.com/docs/v3/Plugins/
Codex Web Motion Overlay
The upstream GreenSock official skill content above is the primary GSAP guidance. This local overlay adds Codex-specific progressive-disclosure resources, static audit scripts, evals, and portable source metadata. Keep GSAP API behavior aligned with GreenSock's official skill and docs; use this overlay for validation, local boundaries, and report shape.
Local Boundaries
- Use gsap-scrolltrigger for ScrollTrigger-specific scene control.
- Respect GSAP package license and plugin availability.
- Do not invent imports for plugins absent from the public package or local dependency set.
Local Workflow
- Check installed gsap version and plugin availability.
- Register plugins exactly once in the runtime boundary.
- Keep plugin setup out of hot render paths.
- Verify lifecycle cleanup and license/package constraints.
Local Gotchas
- Plugin imports differ by plugin and package availability; verify before generating code.
- SplitText-style text effects need accessibility and reduced-motion fallbacks.
- Flip needs measured before/after state ownership; do not mix with separate layout animators.
Bundled Resources
references/official-source.md- Official GreenSock plugin skill source. Use this to verify upstream plugin coverage and license.references/plugin-availability.md- Plugin import and availability matrix. Use this before writing imports, registration, or premium-plugin examples.references/plugin-lifecycle.md- Plugin setup, cleanup, and accessibility review. Use this for Flip, Draggable, Observer, SVG, and text plugin implementation review.references/premium-plugin-license-boundaries.md- Plugin availability and license boundaries. Read before generating imports or examples for SplitText, MorphSVG, DrawSVG, Club plugins, or any plugin absent from local dependencies.references/plugin-specific-test-fixtures.md- Plugin-specific fixtures and verification. Read when validating Flip, Draggable, Observer, MotionPath, ScrollTo, SVG, or text plugin behavior.references/docs-plugin-current-notes.md- Copied source excerpt. Load only when exact upstream wording or API detail is needed.references/index.md- Complete reference inventory and routing summary.references/source-ledger.md- Portable source list and copy policy.references/provenance.json- Machine-readable provenance and local-resource metadata.scripts/audit.mjs- Self-contained Codex audit CLI with domain-specific GSAP rules.assets/templates/gsap-plugins-audit-report.md- GSAP audit response template.assets/templates/gsap-plugins-review-checklist.md- GSAP manual review checklist.assets/examples/gsap-plugins-starter.js- Minimal starter fixture/example.evals/trigger-queries.json- Trigger/near-miss eval set.evals/evals.json- Task-quality evals with assertions.
Audit CLI
node scripts/audit.mjs doctor --root . --format json
node scripts/audit.mjs scan --root . --format markdown
node scripts/audit.mjs scan --root . --format json --output gsap-plugins-audit.json
Treat script findings as leads. Verify every finding against current code before changing behavior or reporting it as valid.