Home Guide 5 Ways to Instantly Test JavaScript in Browsers

5 Ways to Instantly Test JavaScript in Browsers

By Jash Unadkat, Technical Content Writer at BrowserStack -

Table of Contents

This article aims to describe 5 ways to quickly test JavaScript code in commonly used browsers.

There are several tools and techniques available using which one can test JavaScript in a browser. Each tool comes with a set of unique features that contribute to different outcomes. While it might be difficult to find a single tool that can meet all your testing needs in this regard, consider using a mix of tools to achieve the desired results.

So, let’s get started with the first tool.


JSFiddle is an online tool that enables a QA to instantly test HTML, CSS, and JavaScript directly in the browser. Introduced in 2009, it was initially known as Mooshell. This tool is compatible with popular JavaScript frameworks like Vue, React, etc. In it, HTML, CSS and JavaScript code snippets are referred to as fiddles. JSFiddle is known for its easy to use interface.

The user can type some JavaScript along with HTML and CSS and verify results on the spot. JSFiddle’s dashboard is quite upfront and divided into three sections for HTML, CSS, and JavaScript. For better understanding, refer to the image below.

Test Javascript Online with JSFiddle

2. Cross-browser testing tools

Although one can instantly test JavaScript using tools like CodePen and JSFiddle, one cannot analyze the behavior of these scripts across different desktop and mobile browsers. This is where online cross-browser testing platforms come into the picture.

Developers and QA’s can check their websites for cross-browser compatibility by using tools like BrowserStack. This platform enables a developer or a QA to instantly test their websites across a range of real mobile devices and browsers like Chrome, Safari, IE, Edge, Firefox, etc.

It also provides other useful functionalities like responsive layout testing and screenshot testing which help to test the validity of JavaScript on a particular web page. Check out this list of browsers and mobile devices provided by BrowserStack for JavaScript testing.

Try Cross Browser Testing for Free

The image below represents the wide range of OS-browser combinations along with real devices provided by BrowserStack for testing purposes, and how easy it is to run your tests.

Cross Browser Testing tool

3. CodePen

Introduced in 2012, CodePen is an online platform similar to JSFiddle for testing HTML, CSS, and JavaScript code snippets also referred to as Pens. One can start scripting in the editor and instantly test the code for desired outcomes. However, CodePen is not just restricted to coding and testing; it operates as a social community that provides an online learning environment. Aspiring developers can share their work on this platform.

With a whopping 33000 active users, it’s one of the largest developer communities online. CodePen provides numerous interesting features like Asset hosting Collab mode and more.

Asset hosting allows the user to drag and drop images directly without worrying about separate hosting. Hosting for other assets like CSS and JSON files are taken care of.

Refer to the image below for a quick glimpse of the interface.

Online JavaScript Testing with Codepen


JavaScript Test Online

4. JSBin

JSBin is an effective alternative to JSFiddle. Its features also enable users to experiment, learn, and teach. The script written and saved in JSBin by a particular user is referred to as a Bin.

For every Bin, a URL is generated. This URL can be shared in order to display the user’s work or to request improvements for the code, thus facilitating increased collaboration.

One can easily start testing their Bins written in HTML, CSS, and JavaScript using the in-built editor. One can also access premium features like Private bins, Dropbox backup by upgrading to the pro version. Refer to the image below for a clear picture of the JSBin UI.

Test Javascript is JSBin


Liveweave is yet another coding platform for developers or web designers to write, test, and share JavaScript, HTML, CSS code with their team members. This platform provides a couple of interesting features like live preview, night mode, and code hinting. Code hinting, in particular, makes programming easier for beginners by providing a drop-down list of commonly used tags. Liveweave also provides support for several popular libraries like jQuery, AngularJS and Bootstrap.

Instant JavaScript Testing with Liveweave

These simple ways to test JavaScript can be immensely helpful to developers and web designers. However, users can also choose to use developer tools for particular browsers. For example, a QA can debug JavaScript errors by using the JavaScript Console in Chrome developer tools. Similarly, DevTools for other popular browsers like Firefox, Safari can be used as an efficient alternative for the tools describes above.

When it comes to testing a website across a large number of browsers, using Devtools for individual browsers can be time-consuming. An intelligent approach might be to use universally usable tools in the early stages of testing and utilize browser-specific Devtools for dealing with browser-specific test cases.

Performing tests on a tool like BrowserStack helps the QA engineer to leverage their test script execution as it covers broader aspects of testing in terms of platforms, browsers, and device coverage. As a result, tools like BrowserStack have an edge over others like Codepen and JSFiddle.

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