> For the complete documentation index, see [llms.txt](https://tools.osintnewsletter.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://tools.osintnewsletter.com/osint-tools/host.io.md).
# Host.io
| **Host.io** | **Quick Overview** |
| ---------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| URL | |
| What it does | Collects and indexes domain and infrastructure data to investigate websites, hosting relationships, DNS records, IP connections, and associated domains. |
| How to use it | Search for a domain, IP address, or hostname to view associated infrastructure data, linked domains, DNS information, and other publicly available technical records. |
| Cost | Partially free. Basic searches are free. Advanced use requires a paid subscription. |
| Account required | No for basic lookups. Yes for advanced features. |
| Cookies | Standard Google Analytics cookies. |
| Ownership | Owned and operated by IDB, LLC (who own IPinfo). |
| Use in Reporting | Mapping connected websites, identifying shared hosting environments, and building a clearer picture of an organisation’s digital footprint. |
### What does Host.io do?
Host.io is essentially a domain lookup platform, helping analysts understand how websites and online infrastructure connect together behind the scenes. The platform can reveal domains hosted on the same IP address, shared hosting providers, DNS configurations, website relationships, infrastructure patterns, as well as historical and associated technical data.
**The lowdown:** Instead of manually checking multiple DNS and hosting sources, Host.io centralises the information into a cleaner and quicker investigative workflow.
### How to Use:
**1. Enter a target website, hostname, or IP address into** [**Host.io**](http://host.io)**’s search bar. (You can do this without logging in/creating an account).**
**2. Analyse associated infrastructure including linked domains, shared IP addresses, DNS records etc. Then pivot and investigate further.**
### Cost
* [ ] Free
* [x] Partially Free
* [ ] Paid
Basic searches are available without payment, while advanced data access and API functionality require a paid subscription.
## Data Processing
### Account Required:
* [x] Yes
* [x] No
No for basic lookups. Advanced features and API access may require registration.
### Cookies:
Standard Google Analytics cookies to track visitor sessions, measure site usage, monitor engagement, and manage analytics performance.
### Use in Reporting
Host.io can support reporting by helping investigators:
* Map online infrastructure.
* Identify technically linked domains.
* Discover hidden or associated websites.
* Corroborate infrastructure overlap.
* Support attribution assessments.
* Build technical timelines and network maps.
[Maltego documentation](https://www.maltego.com/transform-hub/host-io/) explicitly notes Host.io is used by threat intelligence teams and security researchers to enrich domains and support investigative analysis.
| **Capabilities** | **Limitations** |
| ----------------------------------------------------------- | ---------------------------------------------------------------- |
| Domain and IP infrastructure lookup. | Shared hosting can create misleading associations. |
| Discovery of associated and co-hosted domains. | Data may become outdated quickly due to infrastructure changes. |
| DNS and hosting analysis. | Some advanced functionality requires payment. |
| Infrastructure pivoting during investigations. | CDN and cloud services can obscure infrastructure relationships. |
| Helpful for cyber threat intelligence and attribution work. | Does not prove ownership or operational control of a domain. |
### Summary
Host.io is a fast, practical infrastructure intelligence tool that helps investigators uncover relationships between websites, domains, IP addresses, and hosting environments. It works best as a lead-generation and correlation tool rather than definitive proof of attribution.
### Ownership
[Host.io](https://host.io/) is owned and operated by IDB, LLC, the same team that runs the IP geolocation company IPinfo. The domain name data and API platform was created by IPinfo's founder and CEO, [Ben Dowling](https://www.linkedin.com/in/bendowling/).
### Ethical Considerations
* Respect privacy and legal boundaries.
* Avoid intrusive or unauthorised activity.
* Verify findings before publication.
* Understand the risk of false attribution.
* Avoid assuming shared hosting equals operational connection.
### Related Tools:
* [IPinfo](/osint-tools/ipinfo.md)
* [Shodan](/osint-tools/shodan.md)
* BuiltWith
* ViewDNS
#### Sources
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