gsap-performance

A set of guidelines for making GSAP animations run smoothly in web browsers. It focuses on how animated properties affect the browser’s layout and drawing work.

In plain words
What is it for?
Use it when improving GSAP animation performance, investigating low frame rates, or aiming for smooth 60-frame-per-second motion.
Why use it?
It helps reduce stuttering, known as jank, when animations move or change elements. It explains which properties are usually cheaper to animate and how to group browser reads and writes.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/isaacsight/kernel/gsap-performance
Any agent
npx skills add isaacsight/kernel --skill gsap-performance
Clone the repo
git clone --depth 1 https://github.com/isaacsight/kernel

Made for: Claude Code, Codex.

Per session 52 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 989 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 100% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00052 $0.00989
Opus 5 $0.00026 $0.00495
Sonnet 5 $0.00010 $0.00198
Haiku 4.5 $0.00005 $0.00099

Measured 2d ago against content hash cb5408d6fba7, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

gsap-performance scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

100% identical to gsap-performance — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.agents/skills/gsap-performance/SKILL.md · 80 lines

How it starts

The opening of the file, as written. The whole thing — 80 lines — stays where its author put it; the contents beside it link to each section on GitHub.

GSAP Performance

When to Use This Skill

Apply when optimizing GSAP animations for smooth 60fps, reducing layout/paint cost, or when the user asks about performance, jank, or best practices for fast animations.

Related skills: Build animations with gsap-core (transforms, autoAlpha) and gsap-timeline; for ScrollTrigger performance see gsap-scrolltrigger.

Prefer Transform and Opacity

Animating transform (x, y, scaleX, scaleY, rotation, rotationX, rotationY, skewX, skewY) and opacity keeps work on the compositor and avoids layout and most paint. Avoid animating layout-heavy properties when a transform can achieve the same effect.

  • ✅ Prefer: x, y, scale, rotation, opacity.
  • ❌ Avoid when possible: width, height, top, left, margin, padding (they trigger layout and can cause jank).

GSAP’s x and y use transforms (translate) by default; use them instead of left/top for movement.

will-change

Use will-change in CSS on elements that will animate. It hints the browser to promote the layer.

will-change: transform;

Batch Reads and Writes

GSAP batches updates internally. When mixing GSAP with direct DOM reads/writes or layout-dependent code, avoid interleaving reads and writes in a way that causes repeated layout thrashing. Prefer doing all reads first, then all writes (or let GSAP handle the writes in one go).

Many Elements (Stagger, Lists)

  • Use stagger instead of many separate tweens with manual delays when the animation is the same; it’s more efficient.
  • For long lists, consider virtualization or animating only visible items; avoid creating hundreds of simultaneous tweens if it causes jank.
  • Reuse timelines where possible; avoid creating new timelines every frame.

Frequently updated properties (e.g. mouse followers)

Prefer gsap.quickTo() for properties that are updated often (e.g. mouse-follower x/y). It reuses a single tween instead of creating new tweens on each update.

Read the full file on GitHub · 80 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 80 lines · 52 tokens per session scan A cb5408d6fba7

Subscribe to this mod's changes

gsap-performance is a skill published in the GitHub repository isaacsight/kernel (16 stars, last pushed 3d ago), licensed MIT. It adds 52 tokens to every session and 989 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to gsap-performance, differing in 0 lines, and is treated as a copy.

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