Free reverse IP lookup
Enter any IP address and see which company owns it — instantly, no signup. Powered by the same identification engine BusinessMCP runs on every website visitor.
Free tool, fair-use limited (10 lookups/hour). Company data only — no personal information.
Data API
Resolve IPs from your own logs
The same check is an API call and an MCP tool your AI agent can use, on one key. The first 1,000 credits every month are free, no card needed.
IP to company
1 credit per callWhich company, ISP, cloud or VPN is behind an IP address.
GET/api/hub/v1/ip/{ip}
curl https://businessmcp.com/api/hub/v1/ip/17.253.144.10 \
-H "Authorization: Bearer $BUSINESSMCP_API_KEY"MCP tool ip_lookup · full reference
Bulk IP to company
1 credit per itemResolve up to 100 IP addresses per call.
POST/api/hub/v1/ip/bulk
curl -X POST https://businessmcp.com/api/hub/v1/ip/bulk \
-H "Authorization: Bearer $BUSINESSMCP_API_KEY" \
-H "Content-Type: application/json" \
-d '{"ips":["17.253.144.10"]}'MCP tool ip_bulk_lookup · full reference
Reading your results
A company name + domain means the IP belongs to a corporate network — if that IP visited your website, someone at that company was reading your pages.
An ISP or hosting label means the IP is a consumer connection, mobile carrier, VPN, or data center. No employer can be inferred — and any tool that claims otherwise for such IPs is guessing.
One IP at a time is a party trick. The real version watches your website traffic continuously, resolves every business visitor automatically, enriches the company with industry/size/tech-stack, stitches the full page-by-page journey, and alerts you when a hot account returns. That's website visitor identification — and the free plan does it for your site.
Frequently asked questions
How does reverse IP lookup work?
Every IP address is registered to an organization. Business networks resolve to the company that operates them; home and mobile connections resolve to internet providers. This tool queries BusinessMCP’s own IP graph, built nightly from public registry, routing and DNS data, the same graph our visitor identification uses. It names a company only when the evidence says the network is that company’s own; carrier, cloud and VPN ranges are labelled as such rather than guessed at.
Why does my lookup show an ISP instead of a company?
Because that IP belongs to a consumer internet provider, mobile carrier, VPN, or cloud host — not a corporate network. That’s normal: only roughly a quarter to a third of B2B website traffic comes from identifiable business networks. It’s also why serious visitor identification layers additional signals (email domains, form fills) on top of IP data.
Can I look up many IPs at once?
The free tool is limited to 10 lookups an hour. For your own logs, use the IP API: up to 100 IPs per call, with the verdict, network class, confidence, ASN and the evidence behind each answer. For automatic identification of every visitor to your own website, with enrichment, journeys and alerts, use the free BusinessMCP plan.
Is looking up an IP address legal?
Yes. IP-to-organization registration data is business information, publicly registered by design. Identifying the company that operates a network is not personal-data processing; identifying the individual person behind an IP is a different matter and is not what this tool does.