---
updatedAt: 2026-10-28T14:32:44.000Z
agentTools:
projectIndex: https://docs.censys.com/llms.txt
---
# Opt Out of Data Collection
Censys is an internet security platform that helps organizations discover, monitor, and secure their devices on the Internet. Censys regularly probes every public IP address and website, curate and enrich the resulting data, and make it intelligible to defenders.
Enterprises use Censys to protect their networks. CERT groups use Censys data to alert system operators about critical Internet-facing vulnerabilities. Researchers use Censys to improve Internet protocols and understand attacker behavior. For example, Censys data has been used to inform the design of the TLS 1.3 protocol as well as to understand the infrastructure associated with Candiru spyware.
## Censys scanning and data collection
One way that Censys finds publicly-reachable services is by using internet-wide scanning. Censys makes small, harmless connection attempts to every IPv4 address worldwide. When Censys discovers that a server is configured to accept connections, Censys follows up by completing a protocol handshake (e.g., HTTP request) to learn more about the services that are running.
Censys never attempts to bypass any authentication or technical barriers, exploit security problems, or access internal, non-public-facing services. The only data Censys receives is publicly visible information to anyone on the internet who connects to the service. If you would like to verify the benign nature of our scans, you can do so on the independent Greynoise platform.
While Censys scans are not designed to gather personal data (as defined under applicable data protection law), they can sometimes incidentally collect data relating to identifiable individuals as part of the scanning process. This is limited to information that is publicly visible. For example, where a TLS certificate has been issued in an individual's name, where WHOIS registration records are publicly associated with an individual, or where personal information such as a biography is published on the website or service itself. Any such personal data is processed on the basis of Censys' legitimate interests in providing services to customers and the legitimate public interest in keeping the internet safe and secure.
## Allowlist or blocklist scans
If you would like to have a host or website excluded from Censys, but do not control an IP allocation or namespace, you can blocklist the IP ranges that Censys and ASNs that uses for scanning. You can also use this list to permit traffic from Censys scanners.
```
66.132.159.0/24
66.132.148.0/24
66.132.153.0/24
66.132.224.0/24
66.132.186.0/24
66.132.195.0/24
66.132.172.0/24
162.142.125.0/24
167.94.138.0/24
167.94.145.0/24
167.94.146.0/24
167.248.133.0/24
199.45.154.0/24
199.45.155.0/24
206.168.34.0/24
206.168.35.0/24
2602:80d:1000:b0cc:e::/80
2620:96:e000:b0cc:e::/80
2602:80d:1003::/112
2602:80d:1004::/112
AS398722
AS398705
AS398324
```
Additionally, Censys HTTP-based scans use a Censys-specific user agent, which can filter requests from our scanners.
`Mozilla/5.0 (compatible; CensysInspect/1.1; +https://about.censys.io/)`
Blocking connections from Censys' subnets prevents Censys scanners from indexing your services. However, this does not remove historical data from Censys datasets.
Host services are usually removed from Censys Search within 24 to 48 hours after their last recorded observation timestamp.
## Request an exclusion from Censys scans
Networks and websites can request exclusion from Censys scans. To do so, please provide one of the following to `censys-abuse@censys.com`:
* Have a publicly-verifiable WHOIS contact associated with the IP block or domain send an email to that address and request exclusion.
* Please provide official documentation from your domain registrar and your ISP confirming ownership of the domain and IP address.
Due to the dynamic nature of cloud hosting IPs, Censys does not block IPs that are dedicated to cloud hosting.