Discover subdomains via public certificate records plus live DNS checks of common names. Read-only lookups run from your browser — the domain you check is visible to crt.sh and Google DNS, as with any lookup.
Content reviewed October 2026 · About Toolzum
Check a host over HTTPS from your browser — SSL/TLS reachability (which proves the browser validated the certificate chain) plus public issuance history (issuer, expiry, cert count) via crt.sh. No cipher-suite or protocol-version scan: browsers do not expose handshakes.
Look up live A, AAAA, CNAME, MX, TXT, and NS records via DNS-over-HTTPS. Queries go to Google DNS — results display here.
Check SSL/TLS certificate details for any domain via public certificate APIs. View issuer, validity period, days remaining, and SANs. Expiry alerts catch outages before users do — free, no signup.
Looks up bank details from an 11-character IFSC code — bank name, branch, address, city, district, and contact info. Live lookup via the Razorpay IFSC API.
Checks any GSTIN format instantly — decodes state, embedded PAN, entity code, and check digit with Luhn mod-36 verification. Supports bulk file decode (up to 500) with CSV export for accounts teams.
Two sources: public certificate records (crt.sh) show names that ever had a certificate, and live DNS checks probe 24 common names (www, api, mail…). A name missing here can still exist — CNAME-only, unlisted, or firewalled names won't show.
Certificate logs are historical: a name stays listed after the certificate expires or the host is retired. The 'Live' section shows only names that resolve right now.
No — those run wordlists of thousands plus brute-forcing from a server. This tool covers certificate history plus two dozen common names, which catches the usual suspects honestly labeled as such.
Yes — it uses passive public certificate records plus read-only DNS checks. Nothing intrusive touches your servers.