Gentle Kotlin is a gentle and wholesome introduction to Kotlin made by people who really like geeking out about the language.

Many of the efforts from here also led to UIUC’s CS199: IKP - Joyful Kotlin which has it’s own lessons, runnable code examples, lecture recordings on youtube. It is also the home to the jeed playground which is one of the fastest Kotlin playgrounds.Github.


We use the Creative Commons BY-SA License. Basically you can use anything from here as you like provided you source back and link to here as well. The sheep illustrations are by Astha Deep and you can directly attribute to her.


This is a community based project so feel free to contribute, fix typos, or anything really on Github (and add yourself here too if you prefer).

Tech stuff

The site source is on Github running on jekyll and hosted by Netlify. The Kotlin runnable playground is supported by the official Kotlin playground, with embedding pulled from their playground source on GitHub.

Kotlin is developed by JetBrains who also developed IntelliJ, Kotlin Playgrond


Based off Hydeout and forked directly off it. The contributor count might seem higher because of that.