About Tools Hub

Why I built Tools Hub

I was formatting JSON at 11pm and tired of pasting it into sketchy sites that might log my data. I needed IRR calculations for a side project and didn't want to pay for a spreadsheet add-on. I wanted to diff two config files without installing anything. Sound familiar?

So I built Tools Hub: a collection of developer tools that run entirely in your browser. No sign-up, no subscription, no data leaving your device. Each tool does one thing well—format JSON, compute IRR/NPV, compare text, encode Base64—and does it locally. That's the whole idea.

What you'll find here

The tools fall into a few categories:

JSON — Formatter, validator, diff, fix, and JSON-to-code converters
Finance — IRR calculator, NPV calculator, TVM (time value of money), mortgage calculator
Text — Text diff, Markdown editor, Word to Markdown, Base64 encode/decode
Other — HTTP mock server, 2048 game, Sudoku

Everything is client-side. No backend API calls, no server-side processing. You load the page, the tool runs in your browser, and your data stays on your machine.

Privacy by design

All processing happens in your browser. The JSON you paste, the numbers you enter for IRR, the text you compare—none of it is sent to any server. There is no backend that receives your input. The site is built as a static frontend; once the page loads, the tools run locally. That's by design, not as an afterthought. If you're handling sensitive configs or financial data, you can use these tools without worrying about where your data goes.

Who's behind this

Tools Hub is built and maintained by a single independent developer. Not a team, not a company—just one person who needed these tools and decided to share them. The site is built with Next.js, TypeScript, and TailwindCSS. I add new tools based on what I need and what users ask for.

Get in touch

Found a bug? Have a suggestion for a new tool? I'd like to hear from you. Drop me an email:

Email: [email protected]
Response time: Usually within 24–48 hours

If you have a tool idea that would fit the platform, let me know. I evaluate requests and add tools when they make sense.