Hi HN! I've created [UFreeTools](https://www.ufreetools.com/), a collection of developer utilities (60+ tools and growing) that's completely free, ad-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:

1. *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 60+ tools

## Future Plans

I'm planning to add: - Tool configurations sync via local storage - More specialized tools for developers based on feedback

I built it because I needed these tools myself, and I hope others find it useful.

I'd love your feedback, especially on UX, tool suggestions, or if you find any bugs!

[Try UFreeTools](https://www.ufreetools.com/)