Bulk IP Lookup

What is bulk IP lookup?

Bulk IP lookup (sometimes called batch IP lookup or bulk IP whois-style checking) lets you resolve many public IP addresses in one pass. Instead of pasting addresses one at a time, you submit a list and get a table of location and ISP data—ideal when your logs, WAF, mail server, or security tools produce dozens of IPs at once.

IPtoolbox returns country, region, city, and ISP for each valid IP. That is the fastest way to spot patterns (“most hits from one ISP” or “traffic clustered in one country”) before you deep-dive with WHOIS, ASN, blacklist, or map tools.

Bulk IP whois vs this tool

Searchers often type bulk ip whois when they want ownership context for many addresses. Classic WHOIS is registry data (contacts, netblocks, allocation dates) and is usually done per IP or prefix. This page focuses on fast batch geolocation and ISP identification. Workflow that works well:

1. Run bulk lookup to triage the list
2. Pick interesting IPs
3. Run IP WHOIS for abuse contacts
4. Run ASN lookup for routing identity
5. Optional: blacklist check and map

How to use the free bulk IP checker

1. Paste one public IP per line (IPv4 addresses work best for this tool).
2. Or click a sample batch chip to load example public DNS / CDN addresses.
3. Click Look Up (complete the human check if shown).
4. Review the results table; use Map / WHOIS / ASN links for follow-up on any row.

What you get in the results

• IP address — the address you submitted
• Country / region / city — approximate geolocation from public databases
• ISP — internet service provider or organization often associated with the IP
• Errors — invalid or failed lookups are called out so you can clean your list

Geolocation is approximate. Country-level accuracy is usually better than city-level. Mobile carriers, CGNAT, VPNs, and hosting providers can make city data less reliable.

Common use cases

• Security & abuse — cluster attacking IPs from firewall or login logs by ISP/country
• Email / spam — review connecting IPs from mail logs before reporting abuse
• Sysadmin triage — understand where a burst of clients or scanners is coming from
• Allowlist / denylist design — see which networks dominate a sample of traffic
• Research — quickly label a list of IPs from a report or ticket without scripting

Tips for better bulk lookups

• Remove private RFC1918 addresses; they will not map usefully on public data
• Deduplicate the list before submitting
• Keep batches moderate so responses stay fast and reliable
• Treat city-level pins as estimates—confirm critical cases with additional signals
• Never use bulk lookup to harass individuals; respect privacy and local law

Related single-IP tools

Need a map for one address? Use the IP Geolocation Map. Need your own connection only? See What Is My IP? and What's My IP Location?.