Category
Network & Cybersecurity
26 tools · 5 run entirely in your browser
Subnet maths, CIDR aggregation, DNS and mail records, IP ownership, certificate history and HTTP header audits. These are the checks network engineers reach for during an outage — designed to give you an answer in seconds, with the working shown.
All network tools
IPv4 Subnet Calculator
Network, broadcast, host range and binary working for IPv4.
IPv6 Subnet Calculator
IPv6 prefix maths with correct 128-bit address counts.
Public IP Lookup
See your public IP, ISP, ASN and approximate location.
DNS Lookup
Query DNS records over DoH with multiple record types.
MAC Address Lookup
Identify hardware vendors from MAC address prefixes.
SSL Certificate Checker
Check TLS issuer, expiry and covered domains.
HTTP Header Checker
Response headers plus a practical security-header audit.
CIDR Calculator
Test IP membership and summarise multiple CIDR blocks.
IP Address Validator
Validate and classify IPv4 and IPv6 addresses.
MX Lookup
Mail exchanger records with priorities.
SPF Checker
Audit the SPF record that authorises senders.
DMARC Checker
Audit DMARC policy and reporting tags.
DKIM Checker
Read and audit a DKIM selector record.
Reverse DNS Lookup
PTR records with forward-confirmed checks.
DNS Propagation Checker
Compare answers from two independent public resolvers.
HTTP Status Checker
Status codes, redirects and final URL.
Email Header Analyzer
Trace email hops and authentication results.
Broken Link Checker
Test a short list of links for broken responses.
IP Blacklist Checker
Check an IP against common DNSBL zones.
TLS Configuration Checker
Check HTTPS redirects and HSTS headers.
ASN Lookup
Find the ASN and owner of an IP address.
IPv4/IPv6 Compatibility
See whether a domain publishes IPv4 and IPv6 records.
WHOIS Lookup
Read a domain's registry record over RDAP.
Domain Expiry Checker
Check registry expiry dates and days remaining.
BGP Prefix Lookup
Find the routed prefix and origin ASN for an IP.
Internet Speed Test
Measure ping, jitter, download and upload speed.
How these tools handle your data
Each tool page carries a processing label. “Runs in your browser” means the work happens locally with JavaScript. “Public lookup” tools send only the value you type — such as a hostname or MAC address — to a documented third-party API. “Uses a KitJade API” means a small Cloudflare Worker performs the check so that browser CORS rules cannot be bypassed.