CodePen vs Preact

CodePen is a web-based social development environment for creating, testing, deploying, sharing and discovering front-end code. In a Pen, users write HTML, CSS and JavaScript and see a live browser preview. It supports HTML preprocessors such as Markdown, Haml, Slim and Pug, and CSS preprocessors including Sass, Less, Stylus and PostCSS. The CodePen 2.0 editor supports automatic preprocessing, live previews, file systems, version history, collaboration and one-click Pen deployment. Users can add external CSS and JavaScript resources, reuse other Pens, find libraries through CDNjs and import bare npm packages through its compiler. Pens can be embedded on other websites, and CodePen documents a REST API and other embed and prefill options. Pens and Projects are public by default. PRO users can make Pens and Collections private, but anyone with the shared URL can view them without logging in. The free plan includes unlimited public Pens and three files per Pen. Starter costs $8 a month, Developer $12 a month and Super $26 a month. CodePen does not offer a self-hosted version.

Preact has no write-up on Specifiction yet; its figures are above.