Holehe is an open-source intelligence tool that checks whether an email address is registered on over 120 websites and retrieves associated account information.
The tool solves the problem of identifying which online services a given email address has been used to register with. It works by querying the forgotten password functionality of various websites, which typically reveals whether an account exists without triggering security alerts to the target email address. This approach allows reconnaissance without notifying the account holder. The tool runs on Python and can be installed via package managers or Docker.
Holehe suits researchers, security professionals, and investigators conducting email-based reconnaissance. It is particularly valuable for cases where you need to discover the digital footprint of an email address across multiple platforms. The tool's key advantage is that it operates silently—the target email receives no notification of the checks being performed. The README does not compare the tool to alternatives, so no comparative assessment can be made.
The project maintains an active online version accessible through a web interface alongside the command-line tool. Development activity shows ongoing engagement with the codebase through issue tracking and maintenance of the module structure. The tool uses asynchronous operations via the Trio library and httpx for efficient concurrent requests across multiple site checks.
