gsap-utils

1# gsap.utils
2 
3## When to Use This Skill
4 
5Apply when writing or reviewing code that uses **gsap.utils** for math, array/collection handling, unit parsing, or value mapping in animations (e.g. mapping scroll to a value, randomizing, snapping to a grid, or normalizing inputs).
6 
7**Related skills:** Use with **gsap-core**, **gsap-timeline**, and **gsap-scrolltrigger** when building animations; CustomEase and other easing utilities are in **gsap-plugins**.
8 
9## Overview
10 
11**gsap.utils** provides pure helpers; no need to register. Use in tween vars (e.g. function-based values), in ScrollTrigger or Observer callbacks, or in any JS that drives GSAP. All are on **gsap.utils** (e.g. `gsap.utils.clamp()`).
12 
13**Omitting the value: function form.** Many utils accept the value to transform as the **last** argument. If you omit that argument, the util returns a **function** that accepts the value later. Use the function form when you need to clamp, map, normalize, or snap many values with the same config (e.g. in a mousemove handler or tween callback). **Exception: random()** — pass **true** as the last argument to get a reusable function (do not omit the value); see [random()](https://gsap.com/docs/v3/GSAP/UtilityMethods/random()).
14 
15```javascript
16// With value: returns the result
17gsap.utils.clamp(0, 100, 150); // 100
18 
19// Without value: returns a function you call with the value later
20let c = gsap.utils.clamp(0, 100);
21c(150);  // 100
22c(-10);  // 0
23```
24 
25## Clamping and Ranges
26…