DEV Community: Skyhighjinks-Dev

I Built 25 Developer Tools That Never See Your Data

Skyhighjinks-Dev — Sat, 07 Feb 2026 13:21:47 +0000

# I Built 25 Developer Tools That Never See Your Data

## The Problem

Ever pasted a production JWT into an online decoder? Or tested a regex against sensitive log data on some random website? Then spent the next hour wondering if you just leaked credentials?

Yeah, me too.

## The Solution

I built [Nyx Development](https://nyx-development.uk) — a collection of developer tools that run **entirely in your browser**. No server processing. No logging. No tracking.

## What's Inside (14 Tools)

### Text & Data
- **JSON Formatter** - Validate, format, and minify JSON
- **Regex Tester** - Real-time pattern matching with JavaScript flavor
- **Markdown Preview** - Live markdown rendering

### Encoding
- **Base64 Encoder/Decoder** - Standard Base64 operations
- **URL Encoder/Decoder** - Percent encoding for URLs

### Security
- **JWT Decoder** - Inspect JSON Web Tokens safely
- **Hash Generator** - MD5, SHA1, SHA256 checksums
- **Password Generator** - Cryptographically random passwords

### Generators
- **UUID Generator** - Generate v4 UUIDs
- **Lorem Ipsum** - Placeholder text for mockups

### Design
- **Color Converter** - Convert between HEX, RGB, HSL with live preview

### Code Tools
- **CSS Minifier** - Minify and beautify CSS
- **HTML Formatter** - Format and compress HTML

### Date & Time
- **Unix Timestamp Converter** - Convert epoch to human-readable dates

## Technical Approach

**Stack:**
- Vanilla JavaScript (no framework dependencies)
- Static hosting on Cloudflare Pages
- Zero backend infrastructure

**Privacy by design:**
- All processing happens in the browser
- No analytics cookies
- No user tracking
- No data transmission to servers

**Developer-friendly:**
- Machine-readable catalog at `/tools.json`
- Schema.org markup for AI/CLI integration
- Mobile responsive
- Works offline (after first load)

## Why Vanilla JS?

Every framework adds complexity. For simple utilities, vanilla JS is:
- Faster to load
- Easier to maintain
- More accessible
- Less likely to break with updates

## Use Cases

These tools are specifically useful when you're working with:
- Production credentials (JWT tokens, API keys)
- Sensitive configuration files
- Internal log data
- Private code snippets

Basically, any time you *need* a tool but shouldn't trust a random website with your data.

## What's Next

Currently exploring:
- Diff viewer
- CSV/TSV converter
- SQL formatter
- API request builder

## Try It

**Live site:** [nyx-development.uk](https://nyx-development.uk)
**API catalog:** [tools.json](https://nyx-development.uk/tools.json)

## Feedback Welcome

What tools are you currently using sketchy websites for? What would you want in this format?

Drop a comment or open an issue. Always looking to expand the collection based on actual developer needs.

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*Built with ☕ and a healthy distrust of third-party tool websites.*

I Built 14 Free Developer Tools That Run Entirely in Your Browser

Skyhighjinks-Dev — Thu, 05 Feb 2026 19:30:48 +0000

Every developer has been there — you need to quickly format some JSON, decode a JWT, or check a regex pattern. You Google it, land on a site plastered with ads, wonder if your data is being logged, and reluctantly paste your API response anyway.

I decided to fix this for myself by building Nyx Dev Tools — a collection of 14 free developer utilities that run entirely client-side.

The Tools

Tool	What It Does
JSON Formatter	Format, validate, and minify JSON
Base64 Encoder/Decoder	Encode and decode Base64 strings
UUID Generator	Generate random v4 UUIDs
Hash Generator	MD5, SHA1, SHA256 hash generation
Regex Tester	Real-time regex matching with highlighting
JWT Decoder	Decode and inspect JWT tokens
Timestamp Converter	Unix timestamp ↔ human dates
URL Encoder/Decoder	Percent-encode/decode URLs
Color Converter	Convert between HEX, RGB, HSL
Markdown Preview	Live markdown editor with preview
Password Generator	Cryptographically random passwords
Lorem Ipsum Generator	Configurable placeholder text
CSS Minifier	Minify and beautify CSS
HTML Formatter	Format and minify HTML

Why Client-Side Matters

Every tool runs in your browser using JavaScript. Your data never leaves your machine. No server processing, no logging, no "we may use your input to improve our service."

This matters when you're pasting:

API responses with auth tokens
JWT tokens from production
Database query results
Configuration files with secrets

The Stack

Deliberately minimal:

HTML/CSS/JS — no React, Vue, or any framework
Cloudflare Pages — free hosting, global CDN
No build step — edit a file, deploy
No dependencies — zero npm packages

Each tool is a single HTML file with embedded JavaScript. No bundler, no transpiler, no node_modules.

Developer Guides

I also wrote 15 reference guides that pair with the tools:

Git Commands Cheat Sheet
Regex Guide
Docker Commands
SQL Cheat Sheet
CSS Grid & Flexbox
HTTP Status Codes
JWT Security
And more on Base64, UUIDs, timestamps, markdown, HTML colors, and environment variables

What's Next

Planning to add:

Cron expression builder — visual cron schedule creator
Diff checker — compare two text blocks
QR code generator — generate QR codes client-side
Image to Base64 — convert images without uploading

Try It Out

🔗 nyx-development.uk

All tools are free, no signup required. If there's a tool you'd want added, let me know in the comments.

Nyx Development Tools and Info!

Skyhighjinks-Dev — Thu, 05 Feb 2026 14:35:55 +0000

I have made a new website that I am hoping to keep on expanding with more topics/knowledge as a single source of information for a lot key tools and technologies that I've learnt/experienced over the last 6 years of professional development!

Website: https://nyx-development.uk/
I am not a web developer by nature, I am much closer to a .NET full stack developer with a heavy lean on backend development work, so if there are any issues please do let me know.

In addition to that, if you wish to see any other content, feel free to add suggestions!