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SVG library for transitioning numbers with motion blur

npm version npm downloads

JavaScript odometer or slot machine effect library for smoothly transitioning numbers with motion blur. Library uses functional approach and ES7 Function Bind Syntax. Internally based on SVG.

See the live version.


To install the stable version:

npm install --save bounty


The API is really simple and straigthforward:

import bounty from `bounty`;

bounty({ el: '.js-bounty', value: '£42,000,000' });

You can use it with other options:

import bounty from `bounty`;

  el: '.js-bounty',
  value: '£42,000,000',
  initialValue: '£900,000',
  lineHeight: 1.35,
  letterSpacing: 1,
  animationDelay: 100,
  letterAnimationDelay: 100,
  duration: 3000

If you want to control ongoing animation just use methods from returned object:

import bounty from `bounty`;

const { cancel, pause, resume } = bounty({ el: '.js-bounty', value: '£42,000,000' });

const wait = (delay) => new Promise((resolve) => setTimeout(resolve, delay));

const pasueAndRun = async () => {
  await wait(1500);
  await wait(2000);
  await wait(2000);


Library is built using UMD thus the following usage in HTML is possible.

<div class="js-bounty"></div>
<script src="/bounty.js"></script>
  bounty.default({ el: ".js-bounty", value: "£42,000,000" });

The UMD build is also available on unpkg:

<script src=""></script>

You can find the library on window.bounty.

That's it?

Yea! That's it. Other options like font-family and font-size are taken from computed styles so you can just style it like the other layers.

.js-bounty {
  font-size: 60px;
  font-family: Roboto;
  fill: #fff;
  text-shadow: 1px 1px 5px rgba(0, 0, 0, 0.5);


If you're interested how it's made, see the presentation.


There is a work in progress to implement additional features:

  • from to API.
  • Full ASCII transition support.
  • Control animation.
  • Introduce Webcomponents API <svg-bounty>


The library is available under the MIT license. For more info, see the LICENSE file.