500 browser-based developer tools · All offline · Zero dependencies · One HTML file each
Dev Vault is a collection of 500 standalone HTML tools covering CSS, JavaScript, security, networking, design, data, DevOps, and more.
Every tool is a single HTML file — open it in a browser and it just works. No build step, no npm install, no signup, no tracking.
- 🌐 Open the portal — open
index.htmlto browse all tools by category - 📁 Browse files —
tools/<category>/<name>.html - 🧪 Run tests —
node tests/run.mjs
| Category | Count | Examples |
|---|---|---|
| JavaScript | 132 | Web APIs, patterns, visualizers, engine internals |
| Code | 109 | JSON, regex, JWT, hash, cron, docker, git |
| CSS | 63 | Layout, animation, painting, responsive, container queries |
| Design | 52 | Color, typography, SVG, icon, image, CSS generators |
| Data | 26 | npm, GitHub, pypi, crate, SSL, license |
| Converter | 20 | JSON↔TOML↔YAML↔XML, temperature, IBAN, date |
| Network | 18 | DNS, IPv4/6, HTTP, TLS, WebSocket, MAC |
| Security | 17 | CSP, CORS, JWT, SRI, cookie inspector |
| Crypto | 10 | Hash, HMAC, RSA, Bcrypt, BIP39, OTP |
| Text | 8 | Case convert, slugify, NATO, binary, Unicode |
| Image | 7 | Crop, filter, watermark, Base64, sprite sheet |
| DevOps | 6 | Docker, K8s, Terraform, Grafana |
| Writing | 9 | Markdown, word count, reading time, title score |
| AI | 5 | LLM pricing, prompt cost, model picker |
| Math | 4 | Evaluator, benchmark, geo distance, ETA |
| More... | 14 | Color, API, device, media, SEO, perf, reference |
# Clone
git clone https://github.com/gokuscraper/dev-vault.git
# Open the portal (or open any tool file directly)
open index.html
# Run tests (requires Node.js + Playwright)
npm install
node tests/run.mjs- Single HTML file — view source, inspect, learn
- Fully offline — after first load, everything is local
- Zero telemetry — no analytics, no tracking, no ads
- Dark theme — defaults to dark mode
Some content is sourced from yurukusa/dev-toolkit. Design references CorentinTh/it-tools.
MIT License · Built with ❤️