Bulk IP WHOIS — Geolocation & ASN for Many IPs
How to analyse many IP addresses at once — country, ASN/organisation, hosting provider and reverse DNS — and how to use it for logs, security and abuse.
What IP WHOIS Is — and Why "Bulk"
Every IP address belongs to a network and an organisation. IP WHOIS tells you, for a single IP, which country it's located in, which ASN (autonomous system number) and organisation it belongs to, and which hosting provider sits behind it. But when you have dozens or hundreds of IPs — say from an access log, an email-sender list or a firewall report — checking them one by one is a waste of time.
The Bulk IP WHOIS tool does exactly that job for up to 100 IPs at once: paste the list and get a clean table with country, ASN/organisation, provider and reverse DNS for each one — with CSV export.
What Does ASN Mean?
An ASN (Autonomous System Number) identifies an entire network on the Internet — for example AS13335 is Cloudflare and AS15169 is Google. Combined with the organisation name, the ASN answers the question "who owns and routes this IP". It's more reliable than reverse DNS because it exists even when there's no PTR record (e.g. on CDN addresses).
Analyse a whole list of IPs in seconds:
→ Bulk IP WHOISWhat the Results Table Shows
- Country: the IP's geolocation country (with flag and ISO code).
- ASN / Organisation: the autonomous system number and the organisation it belongs to.
- Provider / Hosting: the recognised provider (Cloudflare, AWS, Hetzner, OTE/Cosmote, etc.) with its logo, where known.
- Reverse DNS (PTR): the hostname mapped to the IP, if set — loaded automatically in the background so the table isn't delayed.
Step by Step with NerdTools
- Open Bulk IP WHOIS.
- Paste the IPs — one per line (IPv4 and IPv6 supported, up to 100). Invalid entries are ignored automatically.
- Click "Check IPs". The table appears instantly; reverse DNS fills in moments later.
- Use Copy CSV to move the results into a spreadsheet or report.
When You Need It
| Scenario | What it shows you |
|---|---|
| Access/mail log analysis | Which countries and networks your traffic or senders come from. |
| Security / abuse research | Which provider hosts suspicious IPs — useful for abuse reports. |
| Email deliverability | Identify the networks behind bots or senders hitting you. |
| Inventory / audit | Quickly map a list of IPs to countries & providers. |
Privacy & Speed
All analysis runs locally on our server using the MaxMind databases — no IP is sent to any external service and there are no rate limits. Even 100 IPs return almost instantly, while reverse DNS is resolved in parallel in the background.