WhatWeb

WhatWeb is an open-source web fingerprinting tool used for web application discovery and profiling.

It is designed to help identify and gather information about web applications and websites by analyzing their response headers, HTML, JavaScript, and other web page components.

WhatWeb is particularly useful for reconnaissance and passive information gathering during web application security assessments, penetration testing, and vulnerability assessments.

1WhatWeb uses a collection of signature-based techniques to "fingerprint" web applications and identify the technologies, frameworks, and software components they use.

This can include web servers, content management systems (CMS), programming languages, JavaScript libraries, and more.

While primarily focused on HTTP and HTTPS, WhatWeb can also analyze other web-related protocols and services, such as FTP, SSH, and SMB, to gather information about a target.