I was tired of sketchy online JSON formatters, so I built a suite of 100+ client-side developer utilities

Hasanul — Wed, 15 Apr 2026 04:52:58 +0000

As developers, we all have that exact same workflow. You get a massive blob of JSON from an API, or a JWT token from a staging environment, and you instinctively Google "JSON Formatter" or "JWT Decoder".

You click the first result. The page is plastered with auto-playing video ads, a massive cookie consent banner blocks your screen, and the tool itself looks like it hasn't been updated since 2012.

Worst of all? You have no idea if the sensitive staging data you just pasted into the textbox is being logged on a random server somewhere.
I finally had enough of this workflow. So, I spent the last few weeks building the exact opposite.

Enter FreeToolkit 🛠️
I built FreeToolkit.co — a platform containing over 100+ raw, focused developer utilities designed around speed, modern UX, and strict privacy.

![FreeToolkit homepage dashboard showing available tools

The Architecture: 100% Client-Side
From a technical perspective, my primary rule for building this was privacy by default. When dealing with Base64 Decoders, JWT Decoders, or converting sensitive CSV data, sending payloads back to a Node.js server for processing is a massive security risk. To solve this, every single one of the 100+ tools runs entirely in your browser using client-side JavaScript.

No API calls are made to process your data.
Everything computes instantly locally.
Your data never leaves your machine.

Built for Speed (Next.js)
Instead of forcing you to navigate through slow, reloading pages to find the tool you need, the entire platform acts as a unified workspace.

use the global sidebar search to instantly filter through utilities.
Natively respects your system's Dark/Light mode preferences.

The Toolkit
I tried to cover almost every random utility I find myself Googling during a standard week of development. Here are some of the dedicated hubs:

📦 JSON Tools (Formatters, Validators, Minifiers, Diff Checkers)
🔐 Cryptography (Bcrypt, SHA-256, HMAC Generators, MD5)
🎨 CSS Tools (Box Shadow Generators, Clip-Path Builders, Minifiers)
⏱️ Date & Time (Unix Timestamp Converters, ISO Formatters)
📄 Text Utilities (Case Converters, Slug Generators, Diff tools)

I would absolutely love to hear feedback from the Dev.to community. If there is a missing utility that you constantly use and want added, let me know in the comments below!

👉 Check it out here: FreeToolkit.co

I built 100+ free developer tools — here's what I learned

Hasanul — Thu, 02 Apr 2026 09:00:19 +0000

Why I built this

Every time I needed a quick JSON formatter or a UUID generator,
I'd Google it and land on some ad-heavy site that barely worked
on mobile. So I decided to build my own.

Six months later, FreeToolkit has 100+ tools and I learned a
lot along the way.

What I built

FreeToolkit is a free collection of
browser-based utilities for developers. No login, no ads,
no data sent to any server.

Some of the most useful ones:

JSON Formatter & Validator — paste messy JSON, get clean output
JWT Decoder — decode any JWT token instantly
Regex Tester — test regex with live match highlighting
UUID Generator — v4 UUIDs with one click
Hash Generator — MD5, SHA1, SHA256, SHA512, bcrypt
Color Converter — hex, RGB, HSL, CMYK
SQL Formatter — clean up messy queries instantly

What I learned building 100+ tools

1. Scope creep is real
I started with 10 tools. Each one suggested 3 more.
Set a limit early.

2. Browser APIs are powerful
90% of these tools need zero server. Crypto, encoding,
parsing — all native now.

3. SEO for tools is different
Each tool page needs its own content. "JSON Formatter"
as a page title isn't enough.

4. Performance matters more than features
Users close tabs in 3 seconds if the tool is slow.

What's next

I'm planning to add:

API access for some tools
Browser extension
More language-specific tools

Would love feedback — what tools do you wish existed?