
JSFiddle
CodeSandbox
GitHub
replit
VS Code
Pastebin.com
JS Bin
A front end web development playground.

Obsidian
Evernote
Notion
Bear
Apple Notes
Notepad++
Keep My Notes
Tired of overloaded note apps? KeepZen is a minimalist, local-first workspace where your notes stay yours. End-to-end encrypted, fast, and secure by design.

Which is more popular?
Based on our record, CodePen seems to be more popular. It has been mentioned 513 times since March 2021.
Website, pricing, platforms and company facts side by side.
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|---|---|---|
| Website | codepen.io | keepzen.io |
| Pricing | — | |
| Company | — | Startup from Kazakhstan · 1 - 9 employees · 2026 |
| Listed in |
In their own words, as submitted to SaaSHub.


No description of CodePen yet.
KeepZen - note-taking app for people who spend more time writing than organizing. No blocks, no databases, no noise. Just you and your thoughts. Come back to clean writing. KeepZen removes the noise and leaves just you and your thoughts — no complex setup, no tracking, just your words in calm,...
What each product offers, as listed by its team.


Possible disadvantages
An editorial look at what each product does well and who it suits.


Overall verdict
Why this product is good
Recommended for
Overall verdict
Why this product is good
Recommended for
Walkthroughs and reviews on video.
What Is Codepen?
More videos
No KeepZen videos yet. You could help us improve this page by suggesting one.
How often each product is chosen within a category, 0–100% relative to the other.


As answered by people managing CodePen and KeepZen.
KeepZen's answer:
KeepZen is built for those who refuse to choose between convenience and privacy. While mainstream tools scan your notes for AI training and "privacy-first" alternatives often require complex manual setup to sync, KeepZen offers a "Third Way." You get absolute end-to-end encryption (E2EE) and seamless multi-device sync out of the box. It’s the only tool that feels as simple as a notepad but is as secure as a digital vault.
KeepZen's answer:
KeepZen occupies the "Goldilocks zone" of note-taking. It is zero-config private: you get the absolute security of end-to-end encryption (E2EE) and the speed of local-first architecture without having to set up a server or manage complex plugins. It’s a professional-grade vault that feels as simple as a piece of paper.
KeepZen's answer:
Our users are "Digital Minimalists"—writers, researchers, and creators who find themselves overwhelmed by the "noise" of modern productivity tools. They are individuals who value their intellectual privacy and want a sanctuary where they can think without being tracked, scanned, or interrupted by AI assistants.
KeepZen's answer:
KeepZen was born from a moment of frustration. I opened a popular note-taking app to capture a fleeting, personal thought, only to be met by a loading spinner and a popup for a new AI feature. The realization was immediate: our digital "private" spaces had become crowded and loud. KeepZen was built to reclaim that silence—creating a tool that stays out of your way and keeps your data truly yours.
KeepZen's answer:
Share your experience with using CodePen and KeepZen. For example, how are they different and which one is better?
External articles and on-site reviews we used to compare the two products.


Codepen is a social network for developers to show off their work, ask and answer questions, and exchange ideas. It's like a Reddit for coding and design, with a large community of talented web developers.
Codepen is a social development environment that allows developers to showcase their work and experiment with HTML, CSS, and JavaScript in a collaborative space. Codepen’s focus on visual and interactive development...
Codepen is a social development environment for front-end designers and developers. Build and deploy a website, show off your work, build test cases to learn.
We have no reviews of KeepZen yet. Be the first one to post
Recommendations tracked on public social media and blogs since March 2021.


> I vividly remember IE and many hacks to have css elements properly working in it… The common advice now is to only use CSS that is supported in the last two major versions of each major browser. You can check any css property's support... - Source: Hacker News / about 1 month ago
Thank you, heartfelt... For sharing an artwork, a miracle! Just in case, have you considered publishing the work at platforms as CodePen, where genius Artists/People express their art, too, as you?: // https://codepen.io/. - Source: Hacker News / 2 months ago
Embed on DEV: If you prefer CodePen embed, create a Pen with that HTML and add to the post as: {% codepen https://codepen.io//pen/ %}. - Source: dev.to / 11 months ago
Tracking KeepZen since Apr 2026.
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A second brain, for you, forever. Obsidian is a powerful knowledge base that works on top of a local folder of plain text Markdown files.
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Bring your life's work together in one digital workspace. Evernote is the place to collect inspirational ideas, write meaningful words, and move your important projects forward.
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Originally founded as a project to simplify sharing code, GitHub has grown into an application used by over a million people to store over two million code repositories, making GitHub the largest code host in the world.
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All-in-one workspace. One tool for your whole team. Write, plan, and get organized.
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