One tab, every tool you need.
Subnet math, DNS lookups, SSL checks, port scanning, JWT decoding, and 100+ more.
Your Swiss tech knife, ready when you are.
Quick Access
Designed by and for IT professionals who live in terminals.
No sign-up walls, no ad clutter, no server queues. Just the tools you reach for daily, tuned for speed and easy on your eyes at 2am.
Instant results
Every calculation runs in your browser - no server round-trip, no waiting.
Shareable URLs
Every result has a unique link. Share a subnet layout or IP lookup with one click.
Dark mode first
Designed for engineers who live in terminals. Easy on your eyes at 2am.
No login, no ads
Free forever. No account required, no tracking, no advertisements.
The one-stop shop engineers actually want.
Plan & troubleshoot faster
Trace DNS propagation across resolvers, validate CIDR layouts, and scan open ports - all client-side, all shareable.
Harden email & hosts
Inspect SPF, DMARC and DKIM records, check certificate chains, and verify HTTP security headers in one place.
Decode & inspect on the fly
Decode JWTs and base64, compare text diffs, inspect response headers, and convert timestamps without leaving the tab.
Stop juggling tabs.
Free networking and security tools for engineers, sysadmins, and DevOps teams. Subnet calculator, CIDR planner, DNS lookup, SPF checker, DMARC checker, port scanner, SSL certificate checker, HTTP security headers, IP geolocation, JWT decoder, traceroute, and 100+ more - all instant, all free, no account required.
Used by network engineers to debug DNS propagation, sysadmins to validate email security records, and developers to inspect HTTP headers and decode tokens. Every result has a shareable URL. Works in any browser, no login, no ads, no rate limits.