I Built a Free Developer Toolkit Where Your Data Stays in Your Browser

Henry — Mon, 31 Aug 2026 13:36:49 +0000

I Built a Free Developer Toolkit Where Your Data Stays in Your Browser

As developers, we constantly need small tools.

Format some JSON.

Decode a JWT.

Encode a string with Base64.

Generate a UUID.

Convert a Unix timestamp.

Test a regular expression.

None of these tasks should be complicated.

But I noticed something annoying: I often ended up opening a different website for each task.

And when the data contained API responses, JWTs, configuration files, or other sensitive information, I always had the same question:

Where does my data actually go?

So I decided to build my own solution.

Meet MyKitApp

I built MyKitApp, a collection of free online developer tools designed to be fast, simple, and privacy-friendly.

You can try it here:

https://www.mykitapp.com/

The main idea is simple:

If a tool doesn't need a server, why send the data to a server?

MyKitApp is designed around browser-based processing, so your data can stay in your browser instead of being unnecessarily uploaded to a backend.

What can you do with it?

There are currently tools for several common developer tasks.

JSON

JSON Formatter
JSON Validator
JSON Minifier
JSON Viewer
JSON to XML
JSON to YAML
JSON Escape / Unescape

Encoding

Base64 Encoder
Base64 Decoder
URL Encoder
URL Decoder
HTML Encoder
HTML Decoder

Security & Authentication

JWT Decoder
JWT Generator
SHA-256 Hash Generator
MD5 Generator

Generators

UUID Generator
Password Generator
Random String Generator
Lorem Ipsum Generator
Barcode Generator
QR Code Generator

Date & Time

Timestamp Converter
Unix Timestamp Converter

Code Formatting

SQL Formatter
HTML Formatter
CSS Formatter
JavaScript Formatter
Markdown Formatter

Regex

Regex Tester

The goal isn't to build the biggest collection of tools possible.

I want these tools to be the kind of utilities developers can bookmark and come back to whenever they need them.

Why browser-based?

Consider a simple JWT decoder.

A JWT can contain information about users, permissions, services, or internal applications.

If all you want to do is inspect the token payload, there is often no technical reason to send that token to a remote server.

The same applies to many other developer tasks.

For example:

JSON formatting
Base64 encoding/decoding
URL encoding/decoding
UUID generation
Hash generation
Regex testing
Timestamp conversion
Code formatting

These operations can often be performed directly in the browser.

That means:

Your input
    ↓
Your browser
    ↓
Result

instead of:

Your input
    ↓
Remote server
    ↓
Processing
    ↓
Response

I think the first architecture should be preferred whenever the task doesn't actually require a backend.

Fast, Private, Free

MyKitApp currently focuses on three principles:

Fast

No account and no unnecessary upload/waiting workflow.

Private

The tools are designed to process data in the browser whenever possible.

Free

No subscription is required to use the tools.

The idea is to make common developer utilities feel more like a small toolbox than another SaaS application.

A small example

Imagine you receive a large JSON response from an API.

Instead of installing another application, you can open the JSON Formatter, paste the response, and immediately get readable JSON.

Or you receive a JWT during development and just want to inspect its header and payload.

Open the JWT Decoder, paste the token, and inspect it directly in the browser.

The goal is to remove friction from these tiny tasks.

What I'm planning next

This is still an early project.

Some of the things I'd like to improve include:

More developer tools
Better keyboard shortcuts
More powerful JSON tools
More code formatters
Better mobile support
More privacy-focused utilities
Offline/PWA support
Better developer documentation
More language support

I'm also interested in understanding which small developer tasks people repeat every day.

Because that's probably where the next useful tool should come from.

I'd love your feedback

If you build software, I'd love to know:

What's the developer tool you use most often?

And more importantly:

What's a small developer task that still feels unnecessarily annoying?

I'm building MyKitApp as a practical toolbox for developers, so suggestions are very welcome.

Try it here:

👉 https://www.mykitapp.com/

If you find a useful tool that's missing, let me know in the comments.

DEV Community: Henry

I Built a Free Developer Toolkit Where Your Data Stays in Your Browser

I Built a Free Developer Toolkit Where Your Data Stays in Your Browser

Meet MyKitApp

What can you do with it?

JSON

Encoding

Security & Authentication

Generators

Date & Time

Code Formatting

Regex

Why browser-based?

Fast, Private, Free

A small example

What I'm planning next

I'd love your feedback