I Built a Collection of 50+ Free Developer Tools That Run Entirely in the Browser

Every developer has that one folder of bookmarks: a JSON formatter here, a Base64 decoder there, a JWT debugger you found on Google three years ago and still trust more than the newer ones. I got tired of juggling a dozen different sites for tasks that take five seconds each, so I built my own collection and put it all in one place.

It's called Solution Toolkit, and it's grown into more than 50 free, browser-based tools.

Why I built it

None of this needed to be complicated. Formatting JSON, decoding a JWT, converting a timestamp - none of that needs a backend, an account, or a subscription. It just needs a page that loads fast and does the one thing you asked it to do.

So that's what I aimed for:

• Free, no sign-up wall
• Privacy-first - most tools run entirely in your browser, so your data never gets uploaded anywhere
• Fast enough that you paste something in and you're done before the page even finishes settling
• Actually useful enough that you'd bookmark it and come back

That last point mattered most. A lot of tools out there are covered in ads, push you through a "premium" upsell for basic functionality, or quietly send whatever you paste off to a server you know nothing about. I wanted the opposite - free, boring, and trustworthy.

What's in it

Here's the full list, grouped the way I use it myself.

Encoding & Decoding

• GZip Base64 Encoder - compress or decompress Base64 strings with GZip
• Base64 Encoder / Decoder
• URL Encoder / Decoder
• HTML Encoder / Decoder
• ASCII to UTF-8 Converter
• ASCII to Hex Converter

JSON Tools

• JSON Formatter & Validator
• CSV to JSON Converter
• JSON to CSV Converter
• JSON to YAML Converter
• YAML to JSON Converter
• JSON to XML Converter
• XML to JSON Converter
• JSON Escape / Unescape

Text & File Tools

• File Size Calculator
• Text Comparison Tool
• Word Frequency Counter
• Text Case Converter - camelCase, snake_case, kebab-case, Title Case, and more

Formatters & Minifiers

• SQL Formatter
• YAML Formatter
• XML Validator
• CSS Minifier
• CSS Beautifier
• JavaScript Minifier
• JavaScript Beautifier
• HTML Minifier
• HTML Beautifier
• Markdown Previewer

Security & Hashing

• JWT Debugger - decode and inspect a token without sending it to a third party
• Text Hash Generator - MD5, SHA-1, SHA-256, SHA-512
• File Hash Generator - same hashes, but for files, computed locally

Converters

• Epoch / Timestamp Converter
• Cron Expression Builder - build and understand cron syntax visually
• Numeral System Converter - decimal, binary, octal, hex
• Color Converter - HEX, RGB, HSL

Code Generators

• UUID Generator & Inspector - v4 and v7, with timestamp inspection
• Mock SQL Data Generator - realistic fake INSERT statements from a schema you define
• QR Code Generator

Image Optimizers

• Image Resizer
• Image Compressor

Image Converters

• PNG to WebP Converter
• WebP to PNG Converter
• PNG to JPG Converter
• JPG to PNG Converter
• JPG to WebP Converter
• WebP to JPG Converter
• JPG to SVG Converter
• PNG to SVG Converter
• WebP to SVG Converter

Go Language Tools

• JSON to Go Struct - paste JSON, get a typed struct back
• Go DynamoDB Code Generator - CRUD code generated from your table schema

Python Utilities

• Visual Table to Python Code - build a table, get a Python list-of-lists back
• Visualize Python Table - paste array code, see it as an editable table

That's 53 tools as of today, and I'm not done adding to it.

What surprised me building this

A few things I didn't expect going in:

1. People care about privacy more than I assumed, even for tools that seem low-stakes. The ones that process everything client-side, with nothing ever touching a server, consistently get better feedback than the ones that don't.
2. The browser can do far more than I gave it credit for. Hashing, image conversion, even SVG generation - all of it runs entirely client-side with the right APIs. No backend required for most of this.
3. Small utilities get used way more often than big features do. Nobody opens a JSON formatter once a month out of curiosity. People open it five times a day without even thinking about it.

I'd like your input

I'm still actively building this out. If there's a browser-based tool you keep wishing existed, or something you find yourself Googling for every few weeks, let me know in the comments. That's usually exactly the kind of thing that ends up on the list next.

🔗 Solution Toolkit