March 28, 2025 - Learn to test JavaScript code in browsers with effective online tools such as JSFiddle, BrowserStack, CodePen, JSBin, & Liveweave.

JSFiddle

Online service for web development

jsfiddle.net

JSFiddle is an online IDE service and online community for testing and showcasing user-created and collaborational HTML, CSS and JavaScript code snippets, known as 'fiddles'. It allows for simulated AJAX calls. In … Wikipedia

Factsheet

Available in English

Founder(s) Oskar Krawczyk, Piotr Zalewa

URL jsfiddle.net

Factsheet

Available in English

Founder(s) Oskar Krawczyk, Piotr Zalewa

URL jsfiddle.net

JSFiddle

jsfiddle.net

JSFiddle - Code Playground

JSFiddle - Test your JavaScript, CSS, HTML or CoffeeScript online with JSFiddle.

Videos

youtube.com

Write a Unit Test for JavaScript (super simple!)

16:57

YouTube

Beginner’s Guide to JavaScript Testing and its Best Practices ...

November 19, 2024

youtube.com

JavaScript Unit Testing Tutorial for Beginners

06:50

YouTube

Jest Tutorial: Start with Unit Testing in JavaScript & Write Better ...

February 26, 2024

youtube.com

Introduction to Jest Testing | JavaScript Unit Tests

01:03:25

YouTube

JavaScript Clean Code Course – Fix Code Smells & Refactor - YouTube

Following is a free list of tools you can use to check, test and verify your JS code:

Google Code Playground
JavaScript Sandbox
jsbin
jsfiddle
pastebin
jsdo.it
firebug
html5snippet.net

Hope this helps.

2 of 3

If you want to edit some complex javascript I suggest you use JsFiddle. Alternatively, for smaller pieces of javascript you can just run it through your browser URL bar, here's an example:

javascript:alert("hello world");

And, as it was already suggested both Firebug and Chrome developer tools have Javascript console, in which you can type in your javascript to execute. So do Internet Explorer 8+, Opera, Safari and potentially other modern browsers.

Jest

jestjs.io

Jest · 🃏 Delightful JavaScript Testing

Jest can collect code coverage information from entire projects, including untested files. Jest uses a custom resolver for imports in your tests, making it simple to mock any object outside of your test’s scope. You can use mocked imports with the rich Mock Functions API to spy on function calls with readable test syntax. Tests fail—when they do, Jest provides rich context why. Here are some examples: Jest is a JavaScript ...

W3Schools

w3schools.com › js › js_quiz.asp

JavaScript Quiz Test

Well organized and easy to understand Web building tutorials with lots of examples of how to use HTML, CSS, JavaScript, SQL, Python, PHP, Bootstrap, Java, XML and more.

MDN Web Docs

developer.mozilla.org › en-US › docs › Learn_web_development › Core › Scripting › Test_your_skills › Functions

Test your skills: Functions - Learn web development | MDN

The aim of this skill test is to help you assess whether you've understood our Functions — reusable blocks of code, Build your own function, and Function return values articles.

LambdaTest

lambdatest.com › home › blog › best 13 tools to test javascript code

Best 13 Tools To Test JavaScript Code | LambdaTest

October 31, 2023 - As JavaScript is a scripting language ... can enable it manually if that’s not the case. In this blog on how to test JavaScript code in browsers, we will continue with Google Chrome as our primary example:...

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Playcode

playcode.io › javascript-compiler

JavaScript Compiler - AI-Powered JS Compiler Online | Free

Learning: Practice JavaScript concepts with instant feedback · Prototyping: Build proof-of-concept apps before committing to a full project · Debugging: Isolate and test problematic code in a clean environment · Sharing: Create shareable code examples for documentation or teaching

BrowserStack

browserstack.com › home › guide › javascript unit testing tutorial

JavaScript Unit Testing Tutorial | BrowserStack

April 19, 2023 - Learn how to perform JavaScript unit testing to run your first unit test with the help of JavaScript Unit Testing Frameworks and code samples

Stack Overflow

stackoverflow.com › questions › 15797262 › sample-html-to-test-javascript-codes

sample HTML to test javascript codes - Stack Overflow

Top answer

1 of 1

<!DOCTYPE html>
<html>
<head>
    <title></title>
</head>
<body>
<script type="text/javascript" src="hehe.js"></script>
<script  >
    useless('Amigo');
    window.onload=useless('Amigo')
</script>

</body>
</html>

You can load the source in a separate script from the inline one that you call it in. Note that this assumes that hehe.js is in the root directory of your site.

For testing js in general jsFiddle is a nice resource that lets you define your html/js/css and experiment with small changes without having to write out all the files.

Web Toolkit Online

webtoolkitonline.com › javascript-tester.html

JavaScript Tester online

Run and test your JavaScript code securely with our 100% local online tool. No data is sent over the Internet – everything runs in your browser! Fast, simple, and secure.

MDN Web Docs

developer.mozilla.org › en-US › docs › Learn_web_development › Core › Scripting › Test_your_skills

Test your skills: JavaScript - Learn web development | MDN

The aim of this skill test is to help you assess whether you've understood our Functions — reusable blocks of code, Build your own function, and Function return values articles.

GitHub

github.com › turingschool-examples › testing-javascript

GitHub - turingschool-examples/testing-javascript: Some example exercises for learning how to test your JavaScript code.

// implementation.js function square(num) { return num * num; } // test.js describe('square', function () { it('returns the square of a number', function () { var result = square(2); assert.equal(result, 4); }); }); From your command line, make ...

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Forked by 59 users

Languages HTML 58.2% | JavaScript 41.8%

MDN Web Docs

developer.mozilla.org › en-US › docs › Web › JavaScript › Reference › Global_Objects › RegExp › test

RegExp.prototype.test() - JavaScript | MDN

The test() method of RegExp instances executes a search with this regular expression for a match between a regular expression and a specified string. Returns true if there is a match; false otherwise. JavaScript RegExp objects are stateful when they have the global or sticky flags set (e.g., ...

Linangdata

linangdata.com › javascript-tester

Javascript Tester

July 8, 2022 - Javascript tester - online javascript tester for editing and testing your javascript code snippets

TestDome

testdome.com › tests › javascript-online-test › 14

JavaScript Online Test | TestDome

The JavaScript online test assesses ... in the JavaScript language and core front-end web development concepts. This test contains a series of live coding tasks that are executed inside the Google Chrome web browser. The assessment includes work-sample tasks such as: Handling user events and manipulating DOM to build responsive web pages. Using classes, objects, and closures to write maintainable and reusable code...

OneCompiler

onecompiler.com › javascript › 3yyjvyt9b

test-code-js - JavaScript - OneCompiler

The editor shows sample boilerplate code when you choose language as Javascript and start coding.

Stack Overflow

stackoverflow.com › questions › 48079636 › testing-javascript-code-from-the-command-line

Testing JavaScript code from the command line - Stack Overflow