About NSToolKit
NSToolKit is a free, no-signup collection of network and developer diagnostic tools built for sysadmins, developers, and IT professionals.
Every tool runs in your browser or executes server-side queries in real time — no accounts, no rate limit walls, no paywalled results. Just enter a domain, IP, or value and get an immediate answer.
What's Included
DNS
DNS lookup, MX records, DNSSEC, reverse DNS, CAA, propagation checker
Email
SPF, DKIM, DMARC, blacklist check, email header analyzer, deliverability test
IP & Network
IP geolocation, WHOIS, ping, traceroute, ASN lookup, port checker, HTTP status
Security
SSL certificate checker, HTTP security headers, password generator, JWT decoder, hash generator
Calculators
Subnet calculator, CIDR range, IPv6 subnet, bandwidth calculator, port reference
Developer
Base64, URL encoder, JSON formatter, regex tester, cron builder, UUID generator, diff tool
How It Works
Tools fall into three tiers:
- Tier 1Runs entirely in your browser — Base64, URL encoding, password generation, JWT decoding. Nothing leaves your machine.
- Tier 2Server-side shell commands — DNS, WHOIS, ping, traceroute, SSL. Your query is validated, executed against authoritative sources, and the result returned. Inputs are not stored.
- Tier 3External API queries — IP geolocation via ip-api.com. The queried IP is sent to that service to resolve location data.
Privacy
NSToolKit does not require an account, does not track individual users, and does not store tool inputs. See our full Privacy Policy for details.
Get in Touch
Found a bug, have a tool suggestion, or need help? Contact us.