# Mojs Curve Editor (opens new window)

npm (opens new window)

MojsCurveEditor is a GUI plugin for interactive custom easings / property curves editing while crafting your animations. Part of mojs tools.

CodePen Example (opens new window)


  • Install it: npm i @mojs/curve-editor
  • Import it: import MojsCurveEditor from '@mojs/curve-editor';'
  • Use it:
const mojsCurve = new MojsCurveEditor();

const tween = new mojs.Tween({
  easing: mojsCurve.getEasing()


# Installation

The MojsCurveEditor depends on mojs >= 0.225.2, tween autoupdates available for mojs >= 0.276.2. Please make sure you've imported mojs (opens new window) library first.

# cdn

<script src="https://cdn.jsdelivr.net/npm/@mojs/curve-editor"></script>

# npm

npm i @mojs/curve-editor

Import MojsCurveEditor into your code:

import MojsCurveEditor from '@mojs/curve-editor';


If you installed it with the CDN option - you should have MojsCurveEditor globally.

# Usage

Construct MojsCurveEditor and provide a name of the curve you're working on:


  const mojsCurve = new MojsCurveEditor({
    name: 'bounce curve'


The name is used to identify record in localStorage to restore the state from when page gets reloaded, so please specify unique names if you use more than one editor on the same page.

After that you can "connect" the curve with your mojs modules by passing a "sample" of the curve to the easing property of the module, like this:

  const myCurve = new MojsCurveEditor({name: 'myCurve'});

  const tween = new mojs.Tween({
    easing: myCurve.getEasing()

  // or

  const shape = new mojs.Shape({
    easing: myCurve.getEasing()

  // or as `property curve`

  const html = new mojs.Html({
    el: '#js-el',
    x: { 0: 100, curve: myCurve.getEasing() }

Each tween/module should have it's out sample of the curve, this means you need to call myCurve.getEasing() send the sample of the curve to the easing property of modules.

If you use mojs>0.276.5 the state of the modules with the curve sample will be updated automatically.

The getEasing function receives options hash:

  easing: myCurve.getEasing({
    // `transform` function that pipes through the current value
    // of the curve so you can transform it
    transform: (k) => { return k; }

After you are happy with the curve you made, you need to change the sample (the myCurve.getEasing() call) with the actual path data which you can get by clicking on the code button ( ):

  const html = new mojs.Html({
    el: '#js-el',
    x: { 0: 100, easing: 'M0, 100 C0, 100 19.8984745544779, 40.10152544552211 30, 30 C40.1015254455221, 19.89847455447789 80, 45 80, 45 C80, 45 100, 0 100, 0 ' }

# Options

const curveEditor = new MojsCurveEditor({
  // name of the curve editor
  name: 'bounce curve',

  // if should preserve state on page reloads
  isSaveState: true,

  // start path - will be loaded on initialization of the curve,
  // e.g. before any user modifications were made. Path of 'M0, 100 L100, 0' is set by default.
  startPath: 'M0, 100 L100, 0',

  // callback on path change, accepts path string
  onChange: function (path) {},

  // if should hide when minimized - useful when you try to embed
  isHiddenOnMin: false

# Public Methods


  // get `easing function` of the curve

  // maximize the curve editor

  // minimize the curve editor

  // toggle `maximize/minimize` methods regarding editor's state

# Shortcuts

  • alt + z - undo curve action
  • alt + x - redo curve action
  • alt + d - delete selected point(s)
  • [3 times] alt + \ - reset curve


The shortcuts works only in the active editor - it should have orange mojs logo indicator at the bottom left.