Tools + answers for the people who keep things running
Your network questions, answered in seconds.
Free, fast, browser-based tools for sysadmins, developers and security folks. No accounts, no uploads, no tracking your inputs. Plus field guides that give you the answer first and the theory after.
Flagship tools
All tools →Security
Password Generator
Cryptographically secure passwords and passphrases, with real crack-time estimates.
Runs in your browser
Network
IPv4 Subnet Calculator
CIDR, masks, ranges and subnet splitting with a visual map of the address space.
Runs in your browser
Dev
JWT Decoder
Decode and inspect JSON Web Tokens locally, with expiry timeline and signature check.
Runs in your browser
Dev
Cron Expression Builder
Build cron schedules with buttons, see the next 10 runs instantly.
Runs in your browser
Network
DNS Lookup
A, AAAA, MX, TXT, NS, CNAME and more, with response times and copy-ready records.
Security
SSL Certificate Checker
Expiry countdown, chain details, protocol and SAN list for any HTTPS host.
By category
Developer tools
Decode, build and debug faster: JWT, cron, encodings and more.
Network tools
Subnets, DNS, IPs: the daily bread of network admins, done right.
Security tools
Passwords, TLS certificates and the things that keep you off incident calls.
Email & DNS tools
SPF, DKIM, MX and the plumbing behind deliverability.
SEO tools
Technical SEO checks that actually move rankings.
Sysadmin tools
Converters, calculators and cheats for people who run servers.
Latest articles
All articles →
Security
How long does it take to crack a password in 2026?
Real crack times for 2026: an 8 character password falls in under 2 hours offline, 16 characters holds for ages. The math, the hardware and what to do.
Security
Are JWTs encrypted? No, and the difference will bite you
JWTs are encoded and signed, not encrypted: anyone holding a token can read every claim. What the signature really protects and what never belongs in a payload.
Email/DNS
SPF, DKIM and DMARC explained: the records your email needs
SPF lists who may send for your domain, DKIM signs each message, DMARC sets the policy when checks fail. How the trio works and how to deploy it safely.