CodePen Projects

In plain words

CodePen Projects is a web-based IDE that allows developers to build websites directly in their browser. Launched in 2017, it provides an integrated environment for writing and testing HTML, CSS, and JavaScript code. The tool is designed for web developers and those learning to code who want a streamlined way to create and prototype websites without setting up local development tools.

written from the facts on this page · September 2026

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  Codesign.io2015 · codesign.io · ▲327

  Visual feedback on everything

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  CodePen2014 · codepen.io · ▲109

  HTML, CSS, and JavaScript editor in the browser.

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  CodePen Projects2017 · blog.codepen.io · ▲4

  CodePen IDE within web browser

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  CodeDesign.AI for WordPress2024 · codedesign.ai · ▲520

  Transform your idea into a gorgeous website with AI

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  Codeplace2016 · ▲257

  Learn how to code by building real web apps

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  CodeSandbox2018 · codesandbox.io · ▲292

  The online code editor for web development

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  /dev/null▲472

  a social network for devs

  Dev tools · 2d ago · dev-null.sh

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  Whiteboard (YC W26) – an open-source IDE for thoughtful software design▲423

  open-source IDE for thoughtful software design. Contribute to devdotfast/whiteboard development by creating an account on GitHub.

  Dev tools · 27d ago · github.com

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  Reladraw – A diagram language where you decide where to place things▲411

  Contribute to reladraw/reladraw development by creating an account on GitHub.

  Dev tools · 25d ago · github.com

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  OpenBot▲362

  Grok Bot alternative: free, local, open-source, multiplayer

  Dev tools · 22d ago · openbot.run

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  Talanoa▲340

  Hi HN, I’m a fullstack developer, and honestly, I’ve lost count of how many side projects I’ve worked on over the years. But one idea kept coming back to me: a different kind of email client. It first came to me in 2014: “What if we could handle emails more like conversations?” Every year, I’d revisit this concept in my “Build Notes.” Ten years later, no one had built exactly what I had in mind — so I finally decided to do it myself. That’s how Talanoa was born. I wanted something focused on people, not timelines. I was tired of marking messages as unread just to remember to reply later, or…

  Dev tools · 20d ago · talanoa.email

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  CoreSpeed▲332

  One MCP for everything your agents need: apps, memory, tools

  Dev tools · 27d ago · corespeed.io

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  Startup School▲1,010

  A free online program to teach you how to start a company

  Life & fun · 2017 · startupschool.org

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  Neuralink▲890

  Elon Musk's newest company, merging our brain with AI

  AI · 2017 · neuralink.com

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  Hardbound 3.0▲739

  Illustrated summaries of bestselling nonfiction books

  Life & fun · 2017 · apps.apple.com

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  Canny▲704

  The easiest way to collect & manage feedback

  Growth · 2017 · canny.io

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  Visual Biographies▲679

  Timelines of amazing lives for visual learners

  Work · 2017

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  Breaker▲676

  The social podcast app 🎧

  Life & fun · 2017 · player.fm