Bulk DNS Lookup

The bulk tool takes a list of inputs — domains or IP addresses, one per line — and runs your chosen check against every entry. You pick the check (DNS records, reverse PTR, domain RDAP, or IP RDAP), and the tool returns one row per input in a single table, ready to export as CSV or JSON.

Use bulk lookups for audits and migrations: verifying a record type across an entire portfolio of domains, mapping a block of IP addresses back to hostnames, or checking registration data on a list of domains or IPs at once. It is far faster than running the single-domain tools one entry at a time. For background on the record types you are auditing, see DNS records explained.

Each row pairs an input with the value the check returned, so you can scan the whole list for outliers — a domain missing a record, an IP with no PTR, a host returning an unexpected status. Sort or filter the exported CSV to group failures together, then drill into any single entry with the matching single-domain tool for the full detail.

A row returns NXDOMAIN. That name does not exist — a typo or a decommissioned domain. A row returns SERVFAIL. The authoritative servers for that name are unreachable or its DNSSEC is failing. A row is blank or malformed. Check the input formatting — one entry per line, no stray characters. To tell the DNS failure modes apart, read NXDOMAIN vs SERVFAIL.

Every run exports to CSV for spreadsheets and audits, or JSON for feeding into another script. Because each row is self-contained, the export doubles as a snapshot you can diff against a later run to spot what changed across your domains over time.