Network Check
Check your public IP address, network provider metadata, download speed, upload speed, latency, and jitter.
Port233 Tools
Free network tools
Use Port233 tools to check your public IP, test internet performance, inspect domain health, review email deliverability records, calculate IPv4 subnets, plan CIDR ranges, allocate VLSM networks, and create secure passwords.
Available tools
IP Subnet & CIDR Planner
Calculate subnet ranges, usable hosts, wildcard masks, CIDR splits, and VLSM allocations for VLANs, firewalls, and cloud networks.
DNS & Domain Health Checker
Check DNS records, website status, SSL certificates, redirects, MX records, SPF, DMARC, nameservers, and common domain configuration issues.
Email Deliverability Checker
Check MX, SPF, DKIM, DMARC, MTA-STS, TLS-RPT, BIMI, and common business email deliverability risks for a public domain.
Password Generator
Generate secure random passwords and passphrases locally in your browser without sending generated values to Port233 servers.
When these tools help
Network checks are useful when a connection changes, a firewall allowlist needs the right public IP, a domain needs DNS or email validation, a VLAN needs a clean address plan, or support teams need repeatable evidence. Port233 keeps these utilities lightweight and quick to use on desktop and mobile devices.