A secret scanner is a cybersecurity tool designed to automatically detect sensitive information, such as passwords, API keys, tokens, or private certificates, that may have been unintentionally included in code repositories or configuration files. These tools scan source code, commit histories, and other files for patterns that match known types of secrets. By identifying and alerting developers to the presence of exposed secrets, secret scanners help prevent data breaches, unauthorized access, and other security incidents. They are commonly integrated into development workflows and continuous integration pipelines to ensure that sensitive data is not pushed to public or internal repositories.