Karma's main goal is to provide a productive environment for developers. Karma's goal is to create a testing environment that developers don't need to set up many configurations. Instead, it will allow them to write the code and receive instant feedback from their tests. You are more productive and creative when you get quick feedback. You can test your code on real browsers, real devices (phones, tablets, etc.) or on a PhantomJS instance headless. You can control the entire workflow from the command line, or your IDE. Simply save a file and Karma's will run all the tests. Karma also monitors all files specified in the configuration file and triggers the test run by sending a signal back to the testing server to notify all captured browsers to run the test again. Each browser then loads the source files within an IFrame and executes the tests. Finally, the browser reports the results back the server.