A collection of system and developer utilities built as a fast, lightweight web app. No backend, no tracking — everything runs in the browser.
Live: syskit.atsiom.com
| Tool | Description |
|---|---|
| chmod | Calculate Unix file permission bits with octal and symbolic output |
| crontab | Build and validate cron expressions with a human-readable schedule preview |
| CIDR | Subnet calculator — usable hosts, network/broadcast address, address range |
| RAID | Compute usable capacity, fault tolerance, and efficiency for common RAID levels |
| sed | Generate sed substitution and deletion commands interactively |
| awk | Build awk one-liners for field extraction and pattern filtering |
| IP info | Look up geolocation and ASN info for any IP address |
| nslookup | Query DNS records (A, AAAA, MX, TXT, NS, CNAME) via DNS-over-HTTPS |
| epoch | Convert Unix timestamps to human-readable time and vice versa |
| DNS prop | Check DNS propagation across multiple global resolvers |
| URL encode | Percent-encode and decode URLs |
| Base64 | Encode and decode Base64 strings with full Unicode support |
| regex | Test regular expressions with live match highlighting and group details |
Prerequisites: Node.js 18+
# Install dependencies
npm install
# Start dev server
npm run dev
# Production build
npm run build
# Preview production build locally
npm run previewThe app deploys automatically to GitHub Pages on every push to main via GitHub Actions.
To deploy manually:
npm run gh-deployThis builds the app and pushes the dist/ directory to the gh-pages branch.
MIT — see LICENSE for details.
This app was built with Claude Code. This README was also generated with Claude Code.