Censys
Ann Arbor, US · Founded 2017 · 14 known investors
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Censys operates an Internet-wide scanning map that provides real-time data on Internet infrastructure, delivered through a platform for exploring exposure, dependencies, and attacker infrastructure. It serves security teams seeking visibility and actionable intelligence about their attack surface and external threats.
Also known as Censys Inc.
Founders & leadership
Censys was founded in 2017 by J. Alex Halderman and Zakir Durumeric.




Board

Investors · 14
How we know: funding news · prnewswire.com · research · Not right? Tell us
How we know: Decibel Partners's portfolio page · funding news · press coverage · the VCSheet dataset · research · venturebeat.com · open dataset · 5k.vc investor directory · Not right? Tell us
How we know: funding news · press coverage · the VCSheet dataset · research · venturebeat.com · open dataset · 5k.vc investor directory · Not right? Tell us
How we know: GV (Google Ventures)'s portfolio page · funding news · press coverage · research · venturebeat.com · open dataset · 5k.vc investor directory · Not right? Tell us
How we know: press coverage · research · Not right? Tell us
How we know: Intel Capital's portfolio page · funding news · press coverage · research · techcrunch.com · Not right? Tell us
How we know: Karma Ventures's portfolio page · Not right? Tell us
How we know: the VCSheet dataset · Not right? Tell us
How we know: OUP (Osage University Partners)'s portfolio page · Not right? Tell us
How we know: funding news · Not right? Tell us
Also in the syndicate · 4
Funding
SEC filings, press & company announcements$110M disclosed across 2 of 13 rounds · 2018–2026
- Undisclosed amountSeries DApr 2026 · 2 sources
Morgan Stanley Expansion Capital (lead), Decibel Partners, Greylock Partners, GV, Intel Capital
Source ↗ - $40MSeries DMar 2026
Morgan Stanley Expansion Capital (lead), Decibel Partners, Greylock Partners, GV, Intel Capital
Source ↗ - $70MraisedMar 2026 · 2 sourcesSource ↗
- Undisclosed amountSeries COct 2023
Decibel Partners (lead), Greylock (lead), GV (lead), Intel Capital (lead), Silicon Valley Bank, a Division of First Citizens Bank (lead), SVB Capital (lead), Ascension Ventures, Four Rivers, Hamilton Lane
Source ↗ - Undisclosed amountSeries AOct 2020
Decibel (lead), GV (lead), Greylock Partners
Source ↗ - Undisclosed amountSeries AAug 2020Source ↗
Source: company announcements and press reports — follow each round's link for the claim.
Company profile
researched Aug 2026Censys operates what it describes as an authoritative, continuously updated map of global Internet infrastructure, built on first-party Internet-wide scanning. The data underpins a platform that security teams use to look up hosts, services, certificates and related infrastructure; identify their own Internet-facing assets, including cloud and unmanaged services; assess third-party and supplier exposure; and track adversary infrastructure such as malicious domains, phishing infrastructure and command-and-control servers.
The product line includes Censys Search for infrastructure lookups, Censys Core, Attack Surface Management for continuous discovery and prioritization of exposures, Adversary Investigation for threat hunting and incident response, and Critical Infrastructure Monitoring for Internet-exposed industrial control and operational technology systems. An enrichment API allows Censys data to be pushed into SIEM, SOAR and threat-intelligence platform workflows. The company also runs a research arm, Censys ARC, publishing threat intelligence, rapid response advisories and reports such as the 2025 State of the Internet Report.
Founding story
Censys grew out of academic research on fast Internet-wide scanning at the University of Michigan, where founder Zakir Durumeric invented ZMap in 2013 to demonstrate that broad Internet measurement could improve security at scale. The project became a free-standing company in 2017. The company describes itself as founded by researchers and cybersecurity practitioners motivated by the absence of trustworthy Internet intelligence in their own investigations.
Business model
Censys sells subscription access to its Internet intelligence platform and products (Search, Core, Attack Surface Management, Adversary Investigation, Critical Infrastructure Monitoring), with published pricing tiers, demo-led enterprise sales, an enrichment API for integration into customer security tooling, and a free community tier that has attracted hundreds of thousands of users.
Commercial platform subscriptions and enterprise contracts alongside a free community offering; the company reported record first-half 2026 growth attributed to enterprise adoption of its Internet intelligence.
Traction
More than 300,000 security practitioners are reported as users, with organizations representing over 50% of the Fortune 500 among customers; the company reported surpassing 350,000 total community users in 2023 and announced record first-half 2026 growth.
Latest developments
In March 2026 Censys announced a $40 million Series D led by Morgan Stanley Expansion Capital plus $30 million in debt financing, to fund AI-driven security operations products and global expansion. It also announced the expansion of its Internet Map to include real-time DNS intelligence, reported record first-half 2026 growth, and continues publishing ARC research such as an analysis of a previously undocumented Russian .NET access framework.
▸Full profile — market position, technology, go-to-market, geography, history
Market position
Censys positions itself as the authoritative source of first-party Internet intelligence, and an investor at Morgan Stanley Expansion Capital described it as widely recognized by customers as the authoritative source for Internet intelligence. It reports use by global governments, Fortune 500 companies, security vendors and critical infrastructure providers.
Differentiation rests on first-party Internet-wide scanning rather than third-party data, breadth and recency of the Internet map (including certificates and DNS), fingerprinting depth, historical records for forensic analysis, and delivery of contextualized, actionable intelligence rather than raw scan output.
Technology
Proprietary Internet-wide scanning technology descended from the ZMap open source scanner, rearchitected into a new scan engine in 2019, producing a real-time map of Internet infrastructure. Capabilities include service and software fingerprinting with CVE context, a large continuously updated database of publicly observed X.509 certificates, DNS intelligence added to the Internet Map, relationship mapping between assets, historical analysis of infrastructure change over time, and risk scoring. The company states it is building AI-driven solutions on top of the platform.
Go-to-market
Demo-request and direct enterprise sales supported by a large free community user base, published pricing, developer documentation and integrations, plus content marketing through the ARC research arm, blogs, webinars, reports and case studies. International go-to-market expansion began in 2024 across the Nordics, France, Australia, Singapore and Japan, and the 2026 funding is earmarked partly for further global expansion.
Security operations centers, threat intelligence and detection engineering teams, exposure and attack surface management programs, governments, Global 2000 and Fortune 500 enterprises, security vendors, and operators of critical infrastructure across cybersecurity, energy and utilities, financial services, government and healthcare.
Geography
Headquartered in Ann Arbor, Michigan, with customers worldwide and go-to-market presence established from 2024 in the Nordics, France, Australia, Singapore and Japan. US and international sales phone lines are listed.
History
The technology originated at the University of Michigan, where Zakir Durumeric created the ZMap fast Internet-wide scanner, released as open source in 2013. Censys Search and data downloads launched in 2015, initially scanning 16 popular Internet protocols. Censys Inc. was founded as a standalone company in 2017. A new proprietary scan engine was built in 2019, and the Attack Surface Management product launched in 2020. Censys passed 350,000 community users in 2023, expanded go-to-market into the Nordics, France, Australia, Singapore and Japan in 2024, and launched the Censys Platform in 2025. In March 2026 it announced $70 million in strategic funding.
Compiled by commissioned research from 26 cited public sources — announcements, filings, and press listed under research sources below.
Key figures
latest reportedCompany-reported or press-reported figures, each dated to when it was claimed — not independently audited.
Founder mafia
2 people who came through Censys went on to found or lead other companies.
Customers & partners
Named customers · 5
Relationships the company or its partners disclosed publicly — case studies, joint announcements, press.
Timeline · 21
launches, deals, and filingsCensys announces record first-half 2026 growth driven by AI-related demand, including 400% growth in $1M+ ARR customers and expansion to 13 countries of operation.
Censys announced $70 million in strategic funding comprising a $40 million Series D equity round led by Morgan Stanley Expansion Capital, with participation from Decibel Partners, Greylock Partners, GV and Intel Capital, and $30 million in debt financing, to accelerate AI-driven security operations products and global expansion.
$70M source ↗
Censys raises $70 million ($40M Series D equity + $30M debt), led by Morgan Stanley Expansion Capital with Decibel Partners, Greylock Partners, GV, and Intel Capital participating; co-founder Zakir Durumeric identified as Founder and CEO.
Censys formally launches the Censys Advanced Research Collective (ARC), a dedicated internet threat research team.
Censys announced the expansion of its Internet Map to include real-time DNS intelligence.
Censys launched the Censys Platform, delivering real-time intelligence for threat detection, risk prioritization and investigations.
Office of the Director of National Intelligence selects Censys to provide its internet intelligence platform to U.S. intelligence agencies under the 'Sentinel Horizon' program.
Censys researchers identify 400+ unintentionally internet-exposed U.S. water treatment systems, coordinating with the EPA on remediation (covered by Bloomberg).
Censys went to market in the Nordics, France, Australia, Singapore, Japan and other regions.
Censys raises $50 million Series C equity plus $25 million debt financing, led by Decibel Partners with GV, Greylock, Intel Capital, Ascension Ventures, Four Rivers Partners, and Hamilton Lane participating.
Censys raises $35 million Series B led by Intel Capital and names Brad Brooks (former OneLogin CEO) as new CEO.
Censys raises $15.5 million Series A led by GV and Decibel Partners, with Greylock Partners participating.
Censys launched its Attack Surface Management platform for securing Internet-facing infrastructure.
Censys architected a new scan engine using proprietary scanning technology.
Censys raises $2.6 million in seed funding.
Censys is spun out and formally incorporated as a company, commercializing the University of Michigan ZMap-based research; Censys Search launches.
MIT Technology Review profiles the University of Michigan internet-scanning research project that would become Censys ('A Search Engine for the Internet's Dirty Secrets').
Censys introduced Censys Search and data downloads, initially scanning 16 popular Internet protocols.
Zakir Durumeric created fast Internet-wide scanning at the University of Michigan and released the ZMap open source scanner.
Zakir Durumeric, then a University of Michigan PhD student, creates the open-source ZMap internet-wide scanning tool, the technical foundation for Censys.
Dated company events from announcements, filings, and press; legal rows summarize public dockets and regulator releases.
In the news
▸Research sources · 26
primary sources listed
- Censyscensys.com · web
- Greylock Partners PortfolioGreylock Partners · company site
- Censys - Greylock Partners portfolio pageGreylock Partners · company site
- Asheem Chandna - Greylock PartnersGreylock Partners · company site
26 public sources were cited for this profile; the first-party ones are listed here.
Frequently asked questions
- What does Censys do?
- Censys maps global Internet infrastructure and sells that intelligence to security teams for exposure and threat work.
- Who founded Censys?
- Censys was founded by J. Alex Halderman, Zakir Durumeric in 2017.
- Who are Censys's investors?
- Censys's investors include Ascension Ventures, Decibel Partners, Greylock Partners, GV (Google Ventures), Hamilton Lane, Intel Capital, Karma Ventures, Mango Capital and 2 more.
- How much funding has Censys raised?
- Censys has disclosed $110M raised across 2 of its 13 known rounds.
- Where is Censys headquartered?
- Censys is headquartered in Ann Arbor, US.










