What is Captcha
On the Internet today, malicious automated scripts drive threats such as spam registration, credential stuffing, and promotion abuse—severely disrupting normal business operations. Alibaba Cloud Captcha blocks these machine-based risks while preserving user experience, giving you a secure and reliable business environment.
Captcha is Alibaba Group’s next-generation bot detection product that goes beyond traditional CAPTCHA. It builds multidimensional behavioral data from user actions, device attributes, and network signals. Using an industry-leading risk control engine powered by a “rules + AI” model, it delivers real-time risk decisions against attacks such as device impersonation, simulated behavior, and brute-force replay.
At the same time, Captcha uses a complete front-end security solution to ensure the authenticity and validity of collected data. Its minimalist verification flow lets genuine users pass the Turing test challenge effortlessly—without thinking.
Supported client-side verification methods
Captcha offers multiple verification methods, including slider CAPTCHA, invisible CAPTCHA, and smart CAPTCHA. These replace traditional CAPTCHA using biometric signals to determine whether a human or a machine is operating the device.
Slider CAPTCHA illustration
Slider CAPTCHA asks users to drag a slider to complete a puzzle. The system analyzes movement trajectory, speed, and other behavioral features to determine if the operator is a real user.
Smart CAPTCHA illustration
Smart CAPTCHA embeds a verification zone as a button within a login form. The button displays the prompt Click to start smart verification. Clicking it triggers the verification flow.
Invisible CAPTCHA illustration
The login interface includes a username field, a password field, and a Log on button. The verification component integrates directly into this form.
Scenarios
Captcha works well in high-risk business scenarios such as logon, registration, promotions, forums, and text messaging.
Benefits
Alibaba Cloud Captcha offers the following advantages:
High fraud detection accuracy: Based on historical big data analysis, fraud detection accuracy exceeds 95%.
Advanced verification technology: Innovative techniques significantly improve blocking of automated bot scripts.
Cross-platform protection: Supports risk control on both PC web and mobile platforms.
Stable and reliable system support: Delivers over 99.99% availability, millisecond-level response time, and handles tens of thousands of concurrent requests per second to keep your business running smoothly.
Front-end code protection: Industry-leading code obfuscation creates a virtually impenetrable verification product.
Diverse verification formats: Offers a rich set of CAPTCHA types tailored to different scenarios, striking the right balance between security and user experience.
Great user experience: Verification is varied, convenient, and engaging.
Secondary CAPTCHA for high-risk requests: Normal requests pass on the first try. Malicious requests are blocked immediately. High-risk requests trigger secondary verification.
Highly customizable configuration: Customize the CAPTCHA component’s appearance to match your business needs. Integrate quickly and deploy efficiently.