1# Benchmark.js v2.1.4
2
3A [robust](https://mathiasbynens.be/notes/javascript-benchmarking "Bulletproof JavaScript benchmarks") benchmarking library that supports high-resolution timers & returns statistically significant results. As seen on [jsPerf](https://jsperf.com/).
4
5## Documentation
6
7* [API Documentation](https://benchmarkjs.com/docs)
8
9## Download
10
11 * [Development source](https://raw.githubusercontent.com/bestiejs/benchmark.js/2.1.4/benchmark.js)
12
13## Installation
14
15Benchmark.js’ only hard dependency is [lodash](https://lodash.com/).
16Include [platform.js](https://mths.be/platform) to populate [Benchmark.platform](https://benchmarkjs.com/docs#platform).
17
18In a browser:
19
20```html
21<script src="lodash.js"></script>
22<script src="platform.js"></script>
23<script src="benchmark.js"></script>
24```
25
26In an AMD loader:
27
28```js
29require({
30  'paths': {
31    'benchmark': 'path/to/benchmark',
32    'lodash': 'path/to/lodash',
33    'platform': 'path/to/platform'
34  }
35},
36['benchmark'], function(Benchmark) {/*…*/});
37```
38
39Using npm:
40
41```shell
42$ npm i --save benchmark
43```
44
45In Node.js:
46
47```js
48var Benchmark = require('benchmark');
49```
50
51Optionally, use the [microtime module](https://github.com/wadey/node-microtime) by Wade Simmons:
52
53```shell
54npm i --save microtime
55```
56
57Usage example:
58
59```js
60var suite = new Benchmark.Suite;
61
62// add tests
63suite.add('RegExp#test', function() {
64  /o/.test('Hello World!');
65})
66.add('String#indexOf', function() {
67  'Hello World!'.indexOf('o') > -1;
68})
69// add listeners
70.on('cycle', function(event) {
71  console.log(String(event.target));
72})
73.on('complete', function() {
74  console.log('Fastest is ' + this.filter('fastest').map('name'));
75})
76// run async
77.run({ 'async': true });
78
79// logs:
80// => RegExp#test x 4,161,532 +-0.99% (59 cycles)
81// => String#indexOf x 6,139,623 +-1.00% (131 cycles)
82// => Fastest is String#indexOf
83```
84
85## Support
86
87Tested in Chrome 54-55, Firefox 49-50, IE 11, Edge 14, Safari 9-10, Node.js 6-7, & PhantomJS 2.1.1.
88
89## BestieJS
90
91Benchmark.js is part of the BestieJS *“Best in Class”* module collection. This means we promote solid browser/environment support, ES5+ precedents, unit testing, & plenty of documentation.
92