
CodePen
replit
JSFiddle
StackBlitz
GitHub
VS Code
JS Bin
Online playground for React

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, CodeSandbox seems to be more popular. It has been mentioned 313 times since March 2021.
Website, pricing, platforms and company facts side by side.
|
|
|
|
|---|---|---|
| Website | codesandbox.io | keepzen.io |
| Pricing | ||
| Company | Startup from The Netherlands · 1 - 9 employees · 2017 | Startup from Kazakhstan · 1 - 9 employees · 2026 |
| Listed in |
In their own words, as submitted to SaaSHub.


No description of CodeSandbox 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.
A browser IDE that's actually GOOD? (CodeSandbox.io Review!)
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 CodeSandbox 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 CodeSandbox 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.


Codesandbox is an online code editor and prototyping tool that makes creating and sharing web apps faster. Codesandbox: Online code editor and ide for rapid web development.
CodeSandbox can be thought of as a much more powerful and complete take on JSFiddle. True to its name, CodeSandbox provides a complete code editor experience and a sandboxed environment for front-end development.
We have no reviews of KeepZen yet. Be the first one to post
Recommendations tracked on public social media and blogs since March 2021.


To begin, you can start creating your own react app using the command line or can directly go to CodeSandbox if you want to skip using the command line which is faster. CodeSandbox is an online code editor and prototype tool that speeds... - Source: dev.to / 4 months ago
To begin, you can create a react app using the command line or any code editor (e.g., VSCode). You can also try using CodeSandbox as an online code editor that is simple to use and allows you to deploy your code. - Source: dev.to / 4 months ago
If you are in a rush to open unknown repos, use GitHub Codespaces or codesandbox with Copilot or another AI integration to analyze the repo for malicious intent and to run it in a safe environment. - Source: dev.to / 10 months ago
Tracking KeepZen since Apr 2026.
When comparing CodeSandbox and KeepZen, you can also consider the following products.


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.
Compare Obsidian to CodeSandbox or KeepZen:

Code, create, andlearn together. Use our free, collaborative, in-browser IDE to code in 50+ languages — without spending a second on setup.
Compare replit to CodeSandbox or KeepZen:

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.
Compare Evernote to CodeSandbox or KeepZen:

Test your JavaScript, CSS, HTML or CoffeeScript online with JSFiddle code editor.
Compare JSFiddle to CodeSandbox or KeepZen:

All-in-one workspace. One tool for your whole team. Write, plan, and get organized.
Compare Notion to CodeSandbox or KeepZen: