Software Alternatives, Accelerators & Startups

CodeSandbox VS KeptPDF

Compare CodeSandbox VS KeptPDF and see what are their differences

Note: These products don't have any matching categories. If you think this is a mistake, please edit the details of one of the products and suggest appropriate categories.

CodeSandbox logo CodeSandbox

Online playground for React

KeptPDF logo KeptPDF

Redact, edit, OCR, and sign PDFs entirely in your browser. The file never leaves your device. Free, no account needed.
Visit Website
  • CodeSandbox Landing page
    Landing page //
    2023-07-27
  • KeptPDF Landing page
    Landing page //
    2026-08-22

CodeSandbox

$ Details
Release Date
2017 January
Startup details
Country
The Netherlands
City
Amsterdam
Founder(s)
Bas Buursma
Employees
1 - 9

CodeSandbox features and specs

  • Ease of Use
    CodeSandbox offers an intuitive interface that allows developers to quickly start coding without the need for complex setup or configuration.
  • Instant Collaboration
    The platform supports real-time collaboration, enabling multiple developers to work on the same project simultaneously.
  • Pre-configured Environments
    It provides a variety of pre-configured templates for popular frameworks like React, Vue, and Angular, which saves time on setting up development environments.
  • Integrated Development
    CodeSandbox includes built-in terminal access and npm/yarn package management, making it possible to manage dependencies directly within the editor.
  • Live Previews
    Code changes are instantly compiled and displayed, providing immediate feedback with live previews of the application.
  • GitHub Integration
    Seamless integration with GitHub allows importing and exporting repositories, making it easier to manage version control and workflows.
  • Accessibility
    Being a web-based IDE, CodeSandbox can be accessed from any device with an internet connection, enhancing flexibility and mobility.

Possible disadvantages of CodeSandbox

  • Performance Issues
    Some users experience lag and slower performance, particularly with larger projects, compared to local development environments.
  • Limited Customization
    While convenient, the pre-configured environments might limit advanced customization options available in local IDEs.
  • Dependency on Internet
    As an online platform, a stable internet connection is required to use CodeSandbox effectively, which could be a limitation in areas with poor connectivity.
  • Free Tier Limitations
    The free version comes with certain restrictions on resources and functionality, which might not be sufficient for larger or more complex projects.
  • Security Concerns
    Storing code in an online platform can raise security concerns, especially for sensitive or proprietary projects.
  • Learning Curve
    Despite its ease of use, developers new to online IDEs might face a learning curve in adapting from traditional, local development environments.

KeptPDF features and specs

No features have been listed yet.

Analysis of CodeSandbox

Overall verdict

  • Yes, CodeSandbox is a highly regarded tool among developers, especially for quick prototyping and collaborative coding.

Why this product is good

  • Ease of Use: CodeSandbox provides an intuitive and user-friendly interface, making it accessible for beginners and efficient for experienced developers.
  • Collaboration: Real-time collaborative features allow multiple developers to work on the same project simultaneously.
  • Integration: It offers seamless integration with popular version control systems like GitHub, making it easy to import/export projects.
  • Environment: Supports a wide range of JavaScript frameworks and libraries, such as React, Vue, and Angular, enabling rapid building of applications.
  • Cloud-Based: Being cloud-based means no setup is required, and projects can be accessed anywhere with an internet connection.

Recommended for

  • Front-end Developers: Suitable for developers who want to quickly build and test front-end applications without local setup.
  • Educators and Students: Ideal for teaching and learning coding due to its collaborative and interactive code editing features.
  • Prototypers: Those looking for a fast way to prototype ideas in a conducive and integrated environment.
  • Open Source Contributors: Simplifies the process of reviewing and testing contributions to open-source projects.

CodeSandbox videos

A browser IDE that's actually GOOD? (CodeSandbox.io Review!)

More videos:

KeptPDF videos

No KeptPDF videos yet. You could help us improve this page by suggesting one.

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Category Popularity

0-100% (relative to CodeSandbox and KeptPDF)
Text Editors
100 100%
0% 0
PDF
0 0%
100% 100
Programming
100 100%
0% 0
PDF Readers And Editors
0 0%
100% 100

Questions & Answers

As answered by people managing CodeSandbox and KeptPDF.

What makes your product unique?

KeptPDF's answer:

KeptPDF runs entirely in your browser. Your file, and the text inside it, never leaves your device. Not to an AI, not even to us. You can open your browser's network tab and watch: the document bytes never go out.

Most online PDF tools upload your file to a server first, and some "AI redaction" services quietly send your document text to a third-party model. That is the exact risk people are trying to avoid when they redact something.

KeptPDF also does true redaction. The text is removed from the file, not covered with a black box you can copy out later. Every redaction produces a verification certificate you can share with the file.

Why should a person choose your product over its competitors?

KeptPDF's answer:

Three reasons.

Privacy you can verify, not just a promise. Processing happens locally in the browser, so there is no upload step to trust. We do send anonymous usage counts for quota, and we say so plainly, but never your document.

Real redaction with proof. Removed text is permanently gone, and you get a certificate showing the file was checked for leftover extractable text. Automated detection cannot catch everything, so a final human review is still your job, and the tool says that too.

It works on a phone. Most PDF suites assume a desktop. KeptPDF was built and used on a phone first, so redacting a document while you are standing in a hallway actually works.

How would you describe the primary audience of your product?

KeptPDF's answer:

Anyone who has to hand a document to someone else and needs the sensitive parts gone first.

In practice that is solo attorneys and small law firms, accountants and tax preparers, healthcare and records staff handling requests, HR teams, and individuals dealing with their own medical, legal, or financial paperwork.

The common thread is not an industry. It is a person who cannot upload a confidential file to a random website, and who does not have an enterprise IT budget to solve it.

What's the story behind your product?

KeptPDF's answer:

A family member got seriously ill. We spent most days at the hospital, and straight answers were hard to come by, so we leaned on AI tools to make sense of the records, notes, and lab results.

But you cannot paste a medical record into an AI chat. You have to strip the names, the ID numbers, the diagnoses first. And almost every tool we found either wanted to upload the whole file to a server, or "auto-redacted" by sending the document text to an online AI. That was the exact thing we were trying to avoid.

Most of this was happening on a phone, at a bedside. So I built the tool I needed: redaction that runs on the device, works on mobile, and never sends the file anywhere. That turned into KeptPDF, which is now a full PDF suite with over 20 tools, all local-first.

Which are the primary technologies used for building your product?

KeptPDF's answer:

The app is plain JavaScript with no front-end framework, which keeps it fast and keeps the code auditable.

PDF work happens in the browser using pdf.js for rendering and pdf-lib for writing. Text recognition uses Tesseract running as WebAssembly. Password and encryption handling uses a WebAssembly build of qpdf. It is a Progressive Web App, so it installs and works offline.

The thin server side is Node on Vercel, with Postgres for accounts, Stripe for billing, and Resend for email. None of those ever see a document.

Who are some of the biggest customers of your product?

KeptPDF's answer:

KeptPDF is early and independent, and we do not publish customer names. The product is privacy-first by design: we never see your documents, and we do not track who our users are or what they work on. Publishing a client list would sit badly next to that.

The user base today is mostly solo attorneys, small firms, accountants, and individuals handling their own records.

User comments

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Reviews

These are some of the external sources and on-site user reviews we've used to compare CodeSandbox and KeptPDF

CodeSandbox Reviews

8 Best Replit Alternatives & Competitors in 2022 (Free & Paid) - Software Discover
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.
12 Best Online IDE and Code Editors to Develop Web Applications
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.
Source: geekflare.com

KeptPDF Reviews

We have no reviews of KeptPDF yet.
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Social recommendations and mentions

Based on our record, CodeSandbox seems to be more popular. It has been mentiond 313 times since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.

CodeSandbox mentions (313)

  • React Tutorial Beginner - `useState` and `useEffect` with Example Code
    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 up the creation and sharing of web apps where you can directly deploy your app without any hustle. - Source: dev.to / 3 months ago
  • Event Handling for React Beginners - Tutorial Example Code
    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 / 3 months ago
  • Don't get scammed on an interview.
    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 / 9 months ago
  • How To Install Shadcn UI In React JS
    CodeSandbox Examples: Check out CodeSandbox for live projects using Shadcn UI. Itโ€™s a great way to see the toolkit in action. - Source: dev.to / over 1 year ago
  • Thankful for CodeSandbox
    I am thankful for a platform like CodeSandbox because it allows me to offload majority of the processing power and memory resources to the cloud. With a local VS Code installed, I can tunnel in via a remote connection to work on my projects, tinker, or do a deep-dive on certain topics; all while ensuring that the RPi 4 still has sufficient resources left to run other things in the background. - Source: dev.to / over 1 year ago
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KeptPDF mentions (0)

We have not tracked any mentions of KeptPDF yet. Tracking of KeptPDF recommendations started around Aug 2026.

What are some alternatives?

When comparing CodeSandbox and KeptPDF, you can also consider the following products

CodePen - A front end web development playground.

Smallpdf - PDF document management and conversion suite

replit - Code, create, andlearn together. Use our free, collaborative, in-browser IDE to code in 50+ languages โ€” without spending a second on setup.

iLovePDF - Premium online PDF tool set

JSFiddle - Test your JavaScript, CSS, HTML or CoffeeScript online with JSFiddle code editor.

Sejda - Split, merge and other powerful PDF tools.