UFreeTools

I've created UFreeTools, a collection of developer utilities (100+ tools and growing) that's completely free, and runs entirely in the browser. No data leaves your device - everything is processed locally.

Background

As a developer, I found myself constantly searching for simple utilities like JSON formatters, UUID generators, and color pickers. Most existing options were cluttered with ads, required sign-ups, or sent data to servers. I wanted clean, fast tools that respected privacy.

So I built UFreeTools as a modern SPA using Vue 3 and Vite with:

100% client-side processing for all tools - Progressive loading with dynamic imports (only load what you use) - Dark/light theme support - Offline capability for most tools - Responsive design that works well on mobile

Technical Details

Some of the more technically interesting implementations:

JWT Debugger: Uses WebCrypto API for verification of all common algorithms - Symmetric Encryption: Implements AES-GCM/CBC/CTR with PBKDF2 key derivation - Image Processing: Uses Web Workers for non-blocking operations on large images

Lessons Learned

The biggest challenges were:

Performance optimization: Some tools (like image processors) needed careful optimization to handle large files without freezing the UI 2. Browser API limitations: Working around browser restrictions for certain crypto operations 3. Bundle size management: Keeping the initial load small while supporting 100+ tools