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Hasanul
Hasanul

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

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?


Check it out at freetoolkit.co

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