Castle logo — Defend against bots, fraud, and abuse.

Castle

Defend against bots, fraud, and abuse.

Founded 2015 United States Brooklyn, United States 48 employees Venture round Total: $11.56M Big Data, Cyber Security +3

General Information

Company Name Castle
Founded Year 2015
Location United States Brooklyn, United States
Employees 48
Industries Big Data, Cyber Security, Fintech +2
Funding Stage Venture round
Business Model B2B, SaaS, API
Revenue Model Pay As You Go, Usage Based, Subscription
Social

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About Castle

Castle, founded in 2015, has positioned itself as a pivotal player in the realms of Big Data, Cyber Security, and Fintech. Based in the United States, the company offers advanced solutions to block bad bots, account takeovers, transaction fraud, and spam, distinguishing itself by eliminating the need for CAPTCHAs. Their slogan, "Defend against bots, fraud, and abuse," succinctly captures their core mission.

Aligned with the increasing global demand for enhanced security measures, Castle continues to capture the interest of investors. The latest financial backing was secured in a Venture Round investment on 01 January 2021, led by Page One Ventures.

In an era where cyber threats are a constant concern, Castle offers a robust, CAPTCHA-free defense framework, aligning with the growing trend of businesses seeking to optimize user experience and security. As such, it presents a promising investment opportunity for those focused on innovation within the privacy and security sectors.

Business keywords: bot protection, fraud prevention, account takeover protection, transaction fraud detection, spam blocking, device fingerprinting, user behavior analysis, cybersecurity solutions, user account security, API integration, e-commerce security, mobile app security, online business protection, real-time threat detection, customer-facing application protection

Services & Products

fraud defense at the edge
in-app fraud detection with SDK
real-time risk analysis and management
custom security flows and rules engine
API integration for threat insights

Target Customers

enterprises businesses handling online transactions platforms vulnerable to bot attacks companies needing real-time fraud detection developers integrating security features

Funding Rounds & Investors (5)

View All
Funding Stage Amount Investors Lead Investors Date
Venture Round Undisclosed 1
Page One Ventures
01 Jan 2021
Series A $9.20M 7
Index Ventures, Y Combinator +5
08 Feb 2019
Seed Round $2.00M 2
First Round Capital, Jenny Haeg
09 Nov 2016
Seed Round Undisclosed -
22 Mar 2016
Seed Round $360.00K -
12 Feb 2015

Castle Alternatives & Competitors

View All Alternatives
Castle vs
IPQS
IPQS United States

Proactively Prevent Fraud™

53 employees
API, Big Data
Castle vs
Verisoul
Verisoul United States

All-in-one platform that helps businesses automate fake account detection.

Seed
10 employees
AI, Analytics
Castle vs
Ravelin Technology
Ravelin Technology United Kingdom

Make smarter decisions on fraud and payments.

Acquired
166 employees
Big Data, Cyber Security

FAQ About Castle

Defend against bots, fraud, and abuse.
Castle was founded in 2015.
Castle is headquartered in Brooklyn, United States.
Castle operates in Big Data, Cyber Security, Fintech, Internet and Privacy and Security. Its work centres on bot protection, fraud prevention, account takeover protection and transaction fraud detection. Its customers include enterprises, businesses handling online transactions and platforms vulnerable to bot attacks.
Castle has a B2B, SaaS and API business model. Its revenue comes from Pay As You Go, Usage Based and Subscription.
Castle has approximately 48 employees.
Castle has completed 5 funding rounds, raising a total of $11.56M. The latest funding stage is Venture round.
Castle offers: fraud defense at the edge, in-app fraud detection with SDK, real-time risk analysis and management, custom security flows and rules engine, API integration for threat insights.
Top alternatives and competitors to Castle include IPQS, Verisoul, Ravelin Technology, ThreatMark, Arkose Labs. These companies operate in related industries and serve comparable markets. You can compare them side by side on Bounce Watch.
Castle and IPQS are both companies in similar industries. Compare their funding, team size, growth signals, and market position on Bounce Watch to see which one fits your needs.

Source: BounceWatch company record for Castle, https://bouncewatch.com/company/castle, updated 27 March 2026. When citing, please name BounceWatch and link this page.

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