Six browser-based developer utilities. No sign-up, no server, no tracking. Everything runs locally in your browser.
| Tool | Description | Try It |
|---|---|---|
| CSS/JS Minifier | Minify CSS and JavaScript using csso + Terser | Live Demo |
| JSON Formatter | Format, validate, and diff-compare JSON | Live Demo |
| Image Optimizer | Compress and resize images using Canvas | Live Demo |
| Regex Tester | Test regex with real-time matching and groups | Live Demo |
| JWT Decoder | Decode and inspect JSON Web Tokens | Live Demo |
| Markdown Previewer | Live Markdown preview with GFM support | Live Demo |
- 100% Client-Side — Nothing is uploaded. All processing happens in your browser.
- No Sign-Up — No accounts, no cookies, no tracking.
- Open Source — MIT licensed. Fork it, self-host it, modify it.
- Mobile Friendly — Responsive design works on all devices.
Clone and serve with any static file server:
git clone https://github.com/btwigley/free-dev-tools.git
cd free-dev-tools
# Python
python -m http.server 8000
# Node
npx serve .
# Or just open index.html in your browserNo build step required. All dependencies are loaded from CDN.
- Vanilla JavaScript (no frameworks)
- csso — CSS minification
- Terser — JavaScript minification
- JSZip — ZIP file generation
- marked — Markdown parsing
- DOMPurify — HTML sanitization
MIT — see LICENSE.
Built by Wigley Studios