Free Network & Domain Tools
Diagnose DNS, SSL, HTTP, and routing issues from a single page. DNS lookup, WHOIS, SSL grading, port scanning, IP geolocation, subnet calculation, redirect tracing, and more.
17 tools in this category · 100% free · No signup
All Network & Domain
DNS Lookup
Look up DNS records (A, AAAA, MX, TXT, NS) for any domain.
Open →WHOIS Lookup
Get full WHOIS data for any domain.
Open →SSL Certificate Checker
Check SSL certificate validity, issuer, and expiry.
Open →HTTP Header Analyzer
Inspect HTTP response headers and security signals.
Open →HTTP Status Code Checker
Check status code of any URL — single or bulk.
Open →Redirect Chain Tracer
Follow every hop in a redirect chain.
Open →Mixed Content Checker
Find HTTP resources loaded on HTTPS pages.
Open →Page Size Analyzer
Measure HTML, CSS, JS, and image weights of any page.
Open →Gzip / Brotli Compression Test
Check if a URL is properly compressed.
Open →IP Address Lookup
Look up location, ISP, and ASN for any IP address.
Open →Subnet Calculator
Calculate subnet ranges, masks, and hosts.
Open →CIDR Calculator
Calculate CIDR notation and address ranges.
Open →Email Address Validator
Validate email syntax, MX records, and deliverability.
Open →Port Checker
Check if a TCP port is open on any host.
Open →Reverse DNS Lookup
Resolve a PTR record from any IP address.
Open →Domain Age Checker
Check the age of any domain from WHOIS data.
Open →SSL Grade Tester
Grade SSL configuration of any HTTPS site.
Open →When to use each network tool
Site not loading? Start with HTTP Status Checker, then DNS Lookup. SSL warnings? SSL Grade Tester shows protocol version, cipher, and certificate expiry. Email deliverability problems? Email Validator checks MX records + disposable status, and Reverse DNS verifies your sending IP has a PTR record (required by Gmail and Microsoft). Building a CDN config? IP Lookup confirms your origin's location. Configuring a firewall? Port Checker verifies the port is actually exposed from the public internet.
How these tools compare to dig and nslookup
Command-line tools (dig, nslookup, curl, openssl) give you raw output and complete control. These web tools give you parsed, color-coded results — faster to read but less flexible. They also work from a different geographic location than your laptop, which is useful for confirming a DNS change has propagated, or that a firewall rule doesn't accidentally block public traffic. Use both: command line for exploration, web tools for quick verification.
DNS, propagation, and TTL
When you change a DNS record, the new value only becomes visible after the TTL (time-to-live) expires on every cache between you and the resolver. That's why your domain might 'work for some people, not others' for 24-48 hours after a change — different resolvers cache for different durations. Our DNS Lookup tool queries authoritative nameservers directly, bypassing caches, so you can confirm your change is live before propagation completes.