Let's be honest, we all have that one folder of bookmarked tools for formatting JSON, testing Regex, or decoding JWTs. But the problem is that 90% of these "free online tools" are slow, cluttered with ads, and worst of all—they send your data to a backend server.
If you are pasting a production API key or customer JSON data into a random website, you are risking a data leak.
That’s exactly why I spent the last few months building FreeClientToolbox. It's a suite of 180+ tools where everything processes 100% locally in your browser.
Here are 7 tools from the box that you'll probably use every day:
1. The Lag-Free XML/JSON Formatter
Most formatters freeze your browser if you paste a 50MB file. Our XML Formatter uses an isolated iframe architecture. You can paste massive dumps and it formats them instantly without freezing the main thread.
2. Secure JWT Decoder
Never paste your JWTs into cloud servers again. Our JWT Decoder parses the token locally using JS. Your payload never leaves your device.
3. Regex Tester
Write and test complex Regular Expressions in real-time. Completely offline-capable once loaded.
4. Bulk Image Compressor
Compress 50 images at once. Because it uses WebAssembly to compress images directly on your CPU, there are no upload/download wait times.
5. SQL Query Beautifier
Clean up those messy 100-line SQL queries before pasting them into your codebase.
6. JSON to TypeScript Interfaces
Paste a JSON response, and it instantly generates the exact TypeScript types and interfaces you need for your frontend.
7. CSS Flexbox Generator
Visually align items and instantly copy the generated CSS code.
The best part? No login walls, no premium tiers, and absolute data privacy.
Check out the full list of 180+ tools here: FreeClientToolbox.com
Which tool do you use the most in your workflow? Let me know below!
Top comments (1)
TextStow could be useful for this workflow — clipboard history + reusable favorites + prompt templates + cleanup for JSON/PDF/URLs. Local-first, free: textstow.com