Network Tools Guide
Everything you need to know about each tool — what it does, when to use it.
Down Detector
Check if a website is down for everyone, or just you.
What it does
The Down Detector sends a request to any website from our servers and tells you whether it responded successfully. If the site is unreachable or returns an error, you'll know it's not just your connection.
When to use it
- A website or app you rely on stops loading
- You want to confirm an outage before reporting it to your team
- You need to rule out a local network issue vs. a server-side problem
How it works
Returns the tested hostname, the HTTP status code, and if the site is up or down.
IP Lookup
Find out who owns an IP address and where it's located.
What it does
Enter any IP address or domain name and get detailed WHOIS information including the organization that owns it, its geographic location, and contact details. Useful for identifying unknown traffic or verifying server locations.
When to use it
- You see an unfamiliar IP in your server logs
- You want to verify where a domain is hosted
- You need abuse or technical contact info for a network block
- You're troubleshooting geo-routing or CDN issues
How it works
We query WHOIS databases for registration data. Returns IP address, hostname, domain, organization, geolocation, and abuse/technical contacts.
Port Scanner
See what's open and know what's exposed.
What it does
Checks whether specific network ports on a server are open or closed. Ports are like doors on a server — each one handles a different type of traffic. Open ports that shouldn't be publicly accessible can be a security risk.
When to use it
- You're setting up a new server and need to verify firewall rules
- A service isn't connecting and you suspect a blocked port
- You want to audit which ports are publicly accessible
- You're troubleshooting connectivity between services
How it works
Performs TCP connection attempts against common ports (or a specific port you specify). Reports open/closed status, service name, and description for each scanned port.
SSL Checker
Verify your SSL certificate is valid and properly configured.
What it does
Analyzes the SSL/TLS certificate on any domain. It checks whether the certificate is trusted, expired, matches the hostname, and shows the full certificate chain. Also tests which TLS protocol versions the server supports.
When to use it
- Your browser shows a "Not Secure" or certificate warning
- You just installed or renewed an SSL certificate
- You want to check when a certificate expires
- You need to verify the full trust chain is correct
- You're auditing TLS protocol support (e.g., ensuring TLS 1.0/1.1 are disabled)
How it works
Inspect the certificate for a specific domain. Returns issuer, subject, SANs, validity dates, days remaining, signature algorithm, fingerprint, and serial number for each certificate. Tests TLS 1.0 through 1.3 individually and reports supported ciphers.
Subnet Calculator
All your subnet details, without the math.
What it does
Enter an IP address in CIDR notation (like 192.168.1.0/24 or 2001:db8::/32) and instantly get the network address, broadcast address, subnet mask, usable host range, and total number of hosts. Supports both IPv4 and IPv6.
When to use it
- You're planning IP address allocation for a new network
- You need to quickly calculate a subnet mask or host range
- You're configuring VPC subnets, firewall rules, or routing tables
- You want to verify a CIDR block covers the right range
How it works
Parses CIDR notation for both IPv4 and IPv6. For IPv4: returns network, broadcast, subnet mask, wildcard mask, first/last usable host, and host count. For IPv6: returns expanded/condensed forms, first/last host, and total addresses.