--- title: "What Is Reverse IP Lookup? Definition & 2026 Guide" description: "Reverse IP can mean hosted-domain discovery, reverse DNS or company identification. Learn the differences and when to use an IP-to-company API." canonical_url: "https://www.leadpipe.com/blog/glossary-reverse-ip-lookup/" source_url: "https://www.leadpipe.com/blog/glossary-reverse-ip-lookup/" md_url: "https://www.leadpipe.com/blog/glossary-reverse-ip-lookup.md" content_type: "article" pubDate: "2026-01-21T00:00:00.000Z" last_updated: "2026-08-31T00:00:00.000Z" --- # What Is Reverse IP Lookup? Definition & 2026 Guide Quick answer Reverse IP lookup has several meanings: finding domains hosted on an IP, resolving an address to a DNS hostname, or retrieving a company association. For B2B account context, use an IP-to-company product. A company result does not identify an individual visitor or prove IP ownership. Reverse IP lookup is an ambiguous term. It can mean finding domains hosted on an IP address, retrieving a reverse-DNS hostname, or looking up a company associated with an address. These tools answer different questions. For a B2B team trying to add account context, the relevant category is **IP-to-company lookup**. Leadpipe offers that through its [IP to Company API](/product/ip-to-company/), alongside separate visitor-identification and intent products. ## Three meanings to distinguish | Lookup | Input | Typical output | Does it identify a visiting person? | | --- | --- | --- | --- | | Hosted-domain discovery | An IP address | Domains associated with that hosting address | No | | Reverse DNS | An IP address | A DNS hostname, when available | No | | IP to company | An IP address | A provider’s company association and available attributes | No | [HackerTarget](https://hackertarget.com/reverse-ip-lookup/) describes reverse IP in the hosted-domain sense. [DNSChecker](https://dnschecker.org/reverse-dns.php) provides reverse DNS lookup. Neither output should be treated as a list of businesses visiting your website. ## How company lookup works in a B2B workflow Your application supplies an address to a provider that has company mappings. The response may include a company name, website, industry and other [firmographic fields](/blog/firmographic-data/). The provider’s schema and documentation determine what is actually available. A company association can support account research, qualification or routing. That can be enough when your sales process works at the organization level. You do not need to name a person to decide that an account deserves review. But the result does not establish a person’s identity, decision-making authority or purchase intent. Keep the lookup separate from your evidence of website activity and any separately identified visitor. ## Leadpipe’s IP-to-company lookup The documented `GET /v1/data/company` operation accepts one IPv4 or IPv6 address using an organization API key. It returns stored company information in `data`, plus usage metadata in `meta`. - A company result consumes one company-lookup unit. - A null result consumes none and does not start new enrichment. - Repeated company-returning requests consume additional units. - Responses must not be cached or prefetched. Eligible organizations have a separate company allowance equal to their effective identification-plan limit, shared across their API keys. Review the [current API documentation](https://docs.leadpipe.com/ip-to-company/introduction) for access, errors and request pacing. Do not assume identification credits, company lookups and Orbit audiences share one allowance. For implementation decisions, read the [IP enrichment guide](/blog/ip-enrichment/). ## What makes a company association uncertain? An IP can represent shared infrastructure, a VPN, a hosting service or a network used by multiple organizations. A stored mapping can also become stale. A provider may return no result or an association that needs review. Avoid universal claims that company identification always misses remote workers or that a particular percentage of traffic must resolve. The relevant evidence is the provider’s current output on your eligible sample, with unknown and disputed cases retained. A null result does not prove that no business uses the address. A complete company record does not prove legal ownership of the IP. These are different claims from the stored association the endpoint supplies. ## How to evaluate a company lookup tool 1. Define the account decision the result should support. 2. Select a permitted sample and independently known associations where available. 3. Check company identity separately from field completeness. 4. Record accepted, rejected and unresolved outcomes. 5. Compare usage rules, operating effort and the required delivery path. Use the [company-tool comparison](/blog/reverse-ip-lookup-tools-compared/) to build a shortlist and the [evaluation kit](/resources/visitor-identification/) to document your criteria. Do not compare a company API’s returned rows with a person-identification product’s match rate as if they were the same output. ## FAQ ### Does reverse IP lookup reveal everyone at an address? No. Hosted-domain, DNS and company lookups do not establish a list of people using a network. A company association is not a named visitor. ### Is company identification useful without person-level data? Yes, when the intended action is account research, segmentation or qualification. If the action requires a specific person, use an appropriate person-identification workflow and verify what the record represents. ### Can I look up an IPv6 address with Leadpipe? Yes. The company API accepts IPv4 and IPv6, normalizes IPv6 spelling and handles IPv4-mapped IPv6 as its IPv4 equivalent. Input must be one address, without a URL, port, CIDR suffix or zone identifier. ### Which Leadpipe product should I use? Use [IP to Company](/product/ip-to-company/) for stored company context, [Identification](/product/identification/) for eligible website visitor records and [Orbit](/product/orbit/) for topic-based intent audiences. Review [current plans](/pricing/) and confirm access for the intended workflow. [Start with Leadpipe](https://dashboard.leadpipe.com/auth/signup): 7 days or 500 profiles, whichever comes first, no card. Company API eligibility must be confirmed for your organization. ## Sources and review basis Published by Leadpipe. Vendor references support product descriptions; recommendations reflect our assessment of fit. Confirm current plan and contract terms before buying. - [Leadpipe IP to company documentation](https://docs.leadpipe.com/ip-to-company/introduction) - [HackerTarget reverse IP lookup](https://hackertarget.com/reverse-ip-lookup/) - [DNSChecker reverse DNS lookup](https://dnschecker.org/reverse-dns.php) [Explore all comparisons and our evaluation method →](/compare/)