CodePen by CodePen Inc. is an online code editor and front-end development playground that makes it easy to prototype, build, and share web experiences. Loved by designers, developers, and educators, CodePen combines a clean interface with real-time previews, community sharing, and collaborative tools—all accessible right in your browser.

- Live Preview Editing: Write HTML, CSS, and JavaScript and instantly see the results as you type, helping you iterate quickly and visually.

- Front-End Framework Support: Built-in settings for using frameworks like React, Vue, Bootstrap, Tailwind, and more, without needing to configure environments.

- Asset Hosting & External Scripts: Easily upload images, fonts, or connect to external libraries and APIs to power your pens and prototypes.

- Projects & Collections: Organize your work with Projects for larger builds or use Collections to curate pens for inspiration, teaching, or client review.

- Embeddable Pens: Showcase your work on portfolios, blogs, or documentation by embedding interactive pens with live functionality.

- Collab Mode & Professor Mode: Collaborate in real time with others or teach interactively with synced views and live code sharing.

- Social & Community Features: Explore, heart, fork, and comment on other users’ pens; follow creators and get inspired by trending front-end experiments.

- Web-Based & Cross-Platform: No installation needed. Access CodePen from any modern browser on desktop or mobile.

CodePen is perfect for front-end developers, UI designers, educators, students, and anyone who wants to quickly prototype or share code in a visual, interactive way.

CodePen turns front-end development into a real-time creative canvas. Whether you’re testing a snippet, building a full UI component, or showcasing your CSS animations, CodePen makes it fast, fun, and shareable.