Wallaby.js runs your JavaScript tests immediately as you type and displays execution results in your code editor. It also provides beautiful test and code coverage reports updated in realtime.
What is wallaby.js?
Wallaby.js is an integrated test runner that enables highly productive JavaScript (or TypeScript, or CoffeeScript) unit testing workflow. It runs your unit tests immediately as you type and displays various execution results, including code coverage and inline messages, right inside your code editor. The tool is insanely fast, because it only executes tests affected by your code changes and runs your tests in parallel.

Wallaby.js is great for doing JavaScript (or TypeScript, or CoffeeScript) TDD (Test-driven development) or BDD (Behavior Driven Development), while also working nicely for other approaches.
There is no vendor, API or framework lock-in when using wallaby.js, because the tool is just using your testing framework and assertion libraries. You are getting a productivity boost with wallaby.js, and you will always be able to run your tests without the tool.
Once you have wallaby.js installed and running in any of the supported editors, you may also use wallaby.js browser app to get the realtime test execution and code coverage reports connected to your editor.
Who is using wallaby.js?
Thousands of individual professional developers and companies (including many of Fortune 500 companies and well-known tech giants) all over the world have already become more productive with wallaby.js. Even software development tools vendors, such as our friends from JetBrains, are trusting wallaby.js to help building other development tools.
What are our users saying?
Trying out @WallabyJS, an amazing JavaScript test runner that works in @code! https://t.co/wRsT1uNfDW
— Scott Hanselman (@shanselman) January 13, 2016
Testing @angular and @typescriptlang using the Angular CLI inside VS @code with @wallabyjs ... I love it! pic.twitter.com/IAnNlPfq0V
— John Papa (@John_Papa) February 20, 2017
Why wait until hitting save to know if your #JavaScript test is right?
— Cory House (@housecor) April 7, 2016
Get real-time test results with Wallaby: https://t.co/cShmvUUP9j
Coding with @wallabyjs easily cut my development-to-complete time in half. Can't recommend it enough.
— Sean Matheson (@controlplusb) April 4, 2016
I've spent a lot of time using @wallabyjs over the last few days. Such a productivity boost! If you haven't tried it yet, you really should!
— Andrew Van Slaars (@avanslaars) September 15, 2017
And I did, thanks @wallabyjs pic.twitter.com/hwmqfsdgba
— let {orta} = therox (@orta) October 21, 2017
Some tools make things easier, some outright change the way we think about coding. For me, @wallabyjs did the latter when it comes to tests.
— H. Yamasaki-Vukelic (@foxbunny) September 19, 2017
.@wallabyjs is a continuous test runner. Check out the plugin overview in our blog: http://t.co/9KwGzfWjN9
— JetBrains WebStorm (@WebStormIDE) April 24, 2015
#Javascript devs, have you met #WallabyJS? Slick, powerful, and…well, fun! https://t.co/mBqTZsnu1k pic.twitter.com/C05qdBBgfs
— Microsoft Developer (@msdev) February 1, 2016
We've started using the parallel, in-editor test runner @wallabyjs in one of our teams. Learn more about it here https://t.co/Ar1G7PHiIW
— OVO Tech Team (@OVOTechTeam) September 4, 2017
@wallabyjs I cannot believe how cool you are. I literally write more and better tests because of you. Everyone should use you. #javascript
— Deric Cain (@DericCain) August 6, 2017
. @tbandixen & @GassmannT explain #angular testing with @KarmaJS & @wallabyjs with @code at #dotnetday17 / @trivadis pic.twitter.com/OVViOIBIem
— DotNetDay CH (@dotnetday_ch) May 23, 2017
Beautiful Seamless JavaScript Testing in 10 Minutes with Wallaby.js: https://t.co/R8LlVXibm4 pic.twitter.com/JpviFJLWUy
— JavaScript Daily (@JavaScriptDaily) September 14, 2015
Worked on reducing down the 30 second wait for 1800 angular unit tests to run in Karma. Got it down to, well, instant with @wallabyjs :D
— Andrew Shelton (@Sheltonial) March 4, 2015
Last week I started using the trial version of @wallabyjs ( after @_ojkwon added it to danger) - it’s stunning.https://t.co/lh3NHtSqOM
— let {orta} = therox (@orta) October 21, 2017
idk how I wrote tests before #wallabyjs, biggest productivity boost ever!@wallabyjs #javascript #tdd
— Oleg Shalygin (@oshalygin) July 31, 2017
Got @wallabyjs to continuously run Jest tests in @WebStormIDE and it's the best thing ever 😍 👏
— kitze (@thekitze) November 25, 2016
📖 Sample config: https://t.co/OWP4zaXnuE pic.twitter.com/AFvvqjHsMO
TDD with @wallabyjs is also great when at the start of your work day you struggle to remember where you left off the day before. pic.twitter.com/Q88adgouzG
— Hendrik Liebau (@KingHenne) May 30, 2017
BLOG: Better #JavaScript & @typescriptlang Testing Experience with @code and @wallabyjs https://t.co/B35ObaaHX8 pic.twitter.com/AOPx0AQz6K
— Andrew Connell (@andrewconnell) September 6, 2016
Refactoring using @wallabyjs is a dream!
— Pisman Kwinten (@KwintenP) November 11, 2016
I can not emphasize enough how awesome @wallabyjs is. I can not imagine development without it anymore! Keep up the nice work. https://t.co/2eoZrxMzeF
— Thomas Sattlecker (@ThomasS09) July 26, 2017
Since I've bought @wallabyjs my code coverage went sky-high. Never thought that this would happen.
— Damian Kamiński (@_dkaminski_) March 21, 2016
Using live code comments /*?.*/ with @wallabyjs in VS @code to measure execution time while writing #js is a mind blowing experience.
— Pierre Arnaud (@epsitec) May 1, 2017
Whoaa. The company I work for just bought me a @wallabyjs license. Unit testing has never been so easy. #javascript
— Edvins Antonovs (@edvinsantonovs) November 14, 2016
This is such an amazing tool, I use it every day and it keeps getting better https://t.co/JSbJVwGfXQ
— Dave Taylor (@davetayls) July 26, 2017
WallabyJS just gave me super powers.https://t.co/b9wEC7mIDR
— Matthew Thornton (@Thornton_Matt) March 20, 2016
im only writing tests because @wallabyjs is awesooome :)
— Arnelle Balane (@arnellebalane) March 4, 2016
Thank you @wallabyjs for your great service. An answer AND solution to my question after 10 minutes already! #awesome #tdd
— Brecht Billiet (@brechtbilliet) September 29, 2016
Now with @wallabyjs and @unexpectedjs, this is a great reference for current libs for JavaScript testing @vzaidman https://t.co/CDKxjxHsDz
— Dave Brotherstone (@bruderstein) April 27, 2017
Not a fan of testing? With https://t.co/EVC6zHAaO6 #wallaby you will be
— LondonJavascript (@thelondonjs) September 6, 2016
For me barrier to doing TDD has always been better tooling esp in large projects, @wallabyjs however has changed that for me
— Nimesh Gurung (@nimgrg) October 4, 2016
Thank you @wallabyjs, an unlivable-without tool
— Alpha Shuro (@alphashuro) February 17, 2016
Just bought my @wallabyjs freedom licence. Its rare that a tool can have such a big impact on my workflow so quickly, I highly recommend it!
— James Henry (@MrJamesHenry) July 26, 2016
Just setup @wallabyjs after not having used it in a while. #AMAZING and worth every penny!
— Matt Apperson 📱👱🏻 (@mattapperson) April 15, 2017
@wallabyjs you make every day working with javascript/typescript more rewarding. Awesome tooling!!!!
— Ken Snyder (@yankeeinlondon) August 13, 2017
Once you try @code + @wallabyjs is hard to live without them.. #typescript #javascript pic.twitter.com/NjHt6pMiOR
— Remo H. Jansen (@OweR_ReLoaDeD) February 15, 2016
Best tool ever for JavaScript. @wallabyjs https://t.co/eUtO2ObEGH
— Tyler Garlick (@TylerGarlick) October 10, 2017
the time has come to renew my @wallabyjs license. I have never spend $100 so happily. It remains my most important tool!
— Dave Benjamin (@zpydee) April 6, 2017
@wallabyjs Seriously great tool, esp running only changed tests/code. I have 1000+ tests & Karma was beginning to be really slow. Thanks.
— Christopher Carson (@chriscarson) December 11, 2016
Well damn, @wallabyjs is just plain awesome for JS testing and coverage. They can expect to sell us a bunch of licenses soon!
— Hilke Heremans (@HHeremans) January 28, 2016
I love your work! Doing original work on a field that's been pretty much stagnant since black/green screens were cool. 🙌
— Nir Benita (@NirBenita) March 29, 2017
This is my #hailcorporate moment, but if you're javascripting, you should do yourself a favor and buy a @wallabyjs licence. Tests != pain
— 🐗 (@mutantantihero) December 10, 2016
Thank you @wallabyjs for an amazing productivity boost!
— Cathal Coffey (@coffeycathal) January 27, 2016
@SSW_TV @dunchunter demoing @wallabyjs at #angularsuperpower , the best tool for writing #angular unit tests pic.twitter.com/6yZPFxSwfy
— Anthony Nguyen [SSW] (@anguyen1909) March 10, 2017
Set up @wallabyjs with typescript for the VS @Code extension I'm working on. There should be something like this for every language, wow
— Cody Hoover (@hoovercj) January 15, 2016
Configured @wallabyjs with @typescriptlang @browserify and @code - took a few minutes - works amazingly! #javascript #typescript #html5
— Łukasz Wójciak (@lukaszwojciak) January 12, 2016
@wallabyjs is so rapid I now find waiting about half a second for NCrunch quite tedious when switching to my C# tests.
— Jamie Humphries (@_jamiehumphries) July 6, 2015
Just purchased a license for @wallabyjs to use with @code. 100% worth the money, so pumped to make #TDD a more natural part of my workflow.
— Ben White (@whtouche) April 17, 2016
just improved my TDD world using @wallabyjs javascript test runner inside #VSCode.
— Piet Groot Kormelink (@pietgk) October 26, 2017
Very Cool Tool check it out :-)
Being extra productive with @wallabyjs #TypeScript and #VisualStudio @code https://t.co/e6A1Jht0Xb #javascript pic.twitter.com/X2PG76AEMU
— Remo H. Jansen (@OweR_ReLoaDeD) February 25, 2016
Now I can see realtime test coverage for RxJS in editor with @wallabyjs , great help to increase test coverage. pic.twitter.com/0gO6Cm06Fi
— OJ Kwon (@_ojkwon) October 29, 2015
can't say enough good about @wallabyjs. Not only is it an amazing tool (whole dept now using), but @ArtemGovorov is great with support.
— Justin Obney (@justinobney) October 8, 2015
Been leaning on @wallabyjs recently. The inline symbols shown per test exposed some amazing optimisation opportunities (and a few bugs). 🤘
— Sean Matheson (@controlplusb) October 30, 2017
Some tools are worth paying for: @wallabyjs is definitely one of them
— Steve Greatrex (@SteveGreatrex) May 8, 2015
Using @wallabyjs a few days now, already greatly increased efficiency of my #tdd cycle. #amazing
— Michael de Wit (@mjwdewit) April 24, 2015
#javascript TDD with @wallabyjs is sooo much more fun than with Karma! Thx @ArtemGovorov for the quick fix of the bug I reported
— Patrick Hund (@wiekatz) April 13, 2015
The best thing that happened to javascript development, testing suddenly became fun. #javascript #tdd http://t.co/quEnBHKjLS @wallabyjs
— João Pedro Serra (@joaaoserra) October 14, 2015
First time of using @wallabyjs all day long at my professional work. Just DOPE! Works like a charm w/TypeScript,ES6,Mocha,Sinon,Chai,Atom.io
— Jens Krause (@sectore) September 2, 2015
@dan_abramov not sure what text editor you are using, but @wallabyjs for atom is incredible/game changing.
— Aaron Jensen (@aaronjensen) August 28, 2015
If you're a JavaScript dev, you have to check out @wallabyjs, you will not be disappointed, put your dev workflow on steroids.
— Wesley Higbee (@g0t4) August 19, 2015
I just did a decently complex refactor on my JS app — and using wallaby.js made it 10x faster.
— Bryan Mills (@diffkid) August 12, 2015
Build break? Forget to change your tests? Well, maybe let Wallaby keep an eye on your code as your write it. http://t.co/zswe5u0hau #testing
— Egor Kloos (@dutchcelt) August 14, 2015
ahh, there is nothing like the sweet smell of 100% code coverage :)
— Dinis Cruz (@DinisCruz) August 8, 2015
Thx @wallabyjs for creating such a great tool pic.twitter.com/1YywqoEaD1
Thanks @wallabyjs for the awesome swag to give away at our testing #angular talk at #ndclondon next week you rock! pic.twitter.com/Mh56BvsRGN
— Duncan Hunter (@dunchunter) January 13, 2017
Just renewed my @wallabyjs and upgraded to all editors. Will it save me $70 of time this year? It will save me $70 of time *this week*!
— Dave Brotherstone (@bruderstein) May 19, 2016
@iamstarkov tried istanbul/isparta. Didn't work well to me. Ended up using @wallabyjs. The best tool money can buy.
— Nikolay Matrosov (@nikthespirit) July 22, 2015
That moment you realise you've forgotten to start @wallabyjs and you've been wasting your time by manually running your unit tests.
— Rich Somerfield (@richie5um) November 18, 2016
Spent the day learning/writing jasmine #angularjs unit tests, have learnt! @wallabyjs makes the experience awesome
— Ken Ross (@kzhen) July 21, 2015
god damn, @WallabyJS is a FAST continuous test runner. Love it! #wallabyjs #jstests #continuoustestrunner #javascript #typescript #melike
— Mikkel Damm (@MikkelDamm) June 23, 2015
Most impressive JS test runner I've seen. http://t.co/93a7KYmjxC Worth a good look.
— Shawn McKay (@Sh_McK) June 21, 2015
@TylorS167 about a year in now and I literally cringe when I don't have it... @wallabyjs 😍
— Justin Obney (@justinobney) December 23, 2016
WOW.. 1 minute into @wallabyjs and I'm reeaaally impressed. Now for some Babel ES6/7 preprocessing
— Einar Ingebrigtsen (@EinarI) June 18, 2015
Man, @wallabyjs is a great test runner. Good support too. 2 hours from initial bug report to them pushing a fix live. :)
— Cody Hatch (@Codayus) June 17, 2015
VERY interesting. @Wallabyjs is *continuous JavaScript testing* for Visual Studio, running as you type. Cool! http://t.co/5c6bJWvV1A
— Scott Hanselman (@shanselman) June 5, 2015
Very impressed with the @wallabyjs team. Fixed an issue with Visual Studio extension within 2 hours! http://t.co/uB6TfEpmzr
— Jamie Humphries (@_jamiehumphries) May 28, 2015
Great example of using @wallabyjs to debug quite a nasty bug introduced by Angular 1.6.0 upgrade (see code comments)https://t.co/7nwKdrPYaN pic.twitter.com/uAkJkNQYdA
— Dinis Cruz (@DinisCruz) December 14, 2016
one of the best javascript engineering support tools you can buy: @wallabyjs
— Manuel Alabor (@swissmanu) May 13, 2015
Great to see @wallabyjs supporting more IDEs. It’s the tool that made TDD JS pain free and possible for me https://t.co/8V1icyUYgB
— Tim Reynolds (@timjreynolds) November 18, 2015
thanks to @ArtemGovorov and @wallabyjs for supporting #mochajs
— Christopher Hiller (@b0neskull) January 16, 2017
@ModernWebUI http://t.co/pxKck6GdEd is def going to change Javascript development, it is amazeballs
— Joshua Gross (@joshuagross) March 23, 2015
Wow. @wallabyjs plugin for @WebStormIDE is a game changer.
— Justin Mandzik (@Justin_Mandzik) March 7, 2015
How much does wallaby.js license cost?
There are no free tools, unless your time has no value. You may find our pricing and licensing details on the pricing page.
Do I need to use some new APIs in my tests or change my tests/code to run them with wallaby.js?
No. Wallaby.js just makes your code editor smarter and your tests to run faster. No need to switch and invest into new frameworks, commands, or APIs - just use your existing testing libraries.
There's no vendor, API or framework lock-in when using wallaby.js. You are getting a productivity boost with wallaby.js, but you will always be able to run your tests without the tool.
What about a list of main features?
-
Supports continuous testing in your code editor:
- WebStorm, IntelliJ IDEA, PhpStorm, Rider, RubyMine, PyCharm
- Visual Studio Code
- Atom Text Editor
- Visual Studio 2013 (Update 4-5),
Visual Studio 2015,
Visual Studio 2017 - Sublime Text
- Supports browser code unit testing (via Chrome, PhantomJs, Electron or node.js) and node.js unit testing.
- Shows live test coverage.
- Allows to quickly inspect object values.
- Provides beautiful realtime test and coverage reports.
- Shows failed expectations, errors and console.log messages inline, where and when they occur.
- Supports many testing frameworks (Jasmine, QUnit, Mocha, Jest + snapshots, and AVA).
- Supports ES.next, JSX, Babel.
- Supports TypeScript, CoffeeScript, Flow.
- Supports Webpack and Browserify.
- Extensible via preprocessors, compilers and more.
- Runs tests affected by code changes.
- Runs tests in parallel.
- Runs selected test(s).
- Captures test execution screenshots.
Where can I find more information about wallaby.js, such as tutorials and samples?
You can find more information, detailed tutorials and sample project links in our documentation.
How is it different from Karma, Mocha runner, Jest CLI runner, etc.?
With other test runners you either need to run your tests manually, or, at best, configure them to run the tests when you save your source code files. Those runners either execute all of your tests or, at best, all tests in affected spec file(s) on code changes. So, as your project grows, it takes more and more time to complete the task. The test execution results are displayed somewhere outside of your code editor, and constant context switching to view the results is a productivity killer.
Wallaby.js runs your unit tests immediately as you type, no need to run anything manually, there's even no need to save files. The tool calculates and runs the minimum required number of tests affected by your code changes, often it is just a single test - and no other testing tool is capable of operating on this level. So no matter how large your project grows - the feedback is almost instant with wallaby.js. Test execution results, including code coverage, are displayed and updated in real time right where you need it — in your code editor, next to the line of code that you're editing.
Can I use wallaby.js with Jasmine, Mocha, QUnit, AVA, or Jest?
Yes. You can use your favorite testing framework, any mocking framework (such as Sinon.js), any assertion library (such as Chai.js, Expect.js, Should.js, Jasmine built-in one, etc.) with wallaby.js. No matter how awesome and fast your testing framework is (like Jest, Mocha, Jasmine, AVA, etc.), wallaby.js makes it even more awesome and faster with the features it adds.
Does wallaby.js support Angular.js, React, Backbone.js, Aurelia, etc.?
Yes. As long as you can write tests for your application, wallaby.js can run them. Check out our tutorials for testing Angular.js and React applications.
What about node.js?
Wallaby.js supports node.js testing. In fact, wallaby.js is written in node.js and we write tests for wallaby.js using wallaby.js.
What about ES.next or JSX?
ES.next is supported both natively for engines that can execute it and via code transpilers, such as Babel. You can see realtime coverage for your generators, classes, arrow functions and much more with wallaby.js. For JSX, not only does wallaby.js understand its syntax, but it also displays coverage inside JavaScript expressions within JSX elements.

What about TypeScript, CoffeeScript, Flow?
Wallaby.js has zero-configuration support for TypeScript and CoffeeScript. Babel is also fully supported.
What about Browserify or Webpack?
Wallaby.js supports both Browserify and Webpack via open source plugins. These plugins not only use incremental compilation, but also leverage browser caching to provide the best performance.
What about code preprocessors like in Karma?
Wallaby.js supports Karma-like preprocessors. Simply provide a function invoking an existing node module.
Do I have to install any standalone applications with wallaby.js?
No. All you need to install is the wallaby.js plugin for your code editor, period. No new command line tools or browser plugins. Our goal is not to add more things between you and the feedback from your tests. In fact, it's the opposite: wallaby.js eliminates any unnecessary context switching, so it's just you and your test feedback, right where and when you write your code.
Do I have to use TDD with wallaby.js or do I have to write my code first?
Wallaby.js is agnostic of any software development techniques. It helps you be more productive whether you're doing JavaScript TDD, writing tests after, or using any mixed approach.
Who stands behind wallaby.js?
At the core of our team are professional JavaScript developers and professional development tools makers. Not only do we know and love the language and the ecosystem, but we have also dedicated our careers to making programmers happier and more productive.
Where is your changelog, and what does the roadmap for wallaby.js look like?
Our changelog is in our public repository.
Wallaby.js roadmap:
- Implementing better test debugging.
- Implementing CI server support.
- Support for more testing frameworks.
- Adding more features to Wallaby.js App.
- Simplifying wallaby.js configuration process.
- Are we missing something? Share your idea or vote for other submitted ideas.
How can I contact you?
Please feel free to send us an email to [email protected] or a message on twitter @WallabyJs and we will get back to you shortly.
How can I subscribe to wallaby.js news?
Follow us on twitter @WallabyJs to receive all the latest news.
We also send out project updates every now and then. Have a look at our past newsletters to decide if they’re worth subscribing to.


