git.legal is described as 'Library scanning and open source license compliance'. There are four alternatives to git.legal, not only websites but also apps for a variety of platforms, including Self-Hosted solutions, SaaS, Windows and Linux. The best alternative is OWASP Dependency-Track, which is both free and Open Source. Other great sites and apps similar to git.legal are Black Duck Software (Paid), FOSSA (Freemium) and WhiteSource (Paid).
WhiteSource is the leading solution for agile open source security and license compliance management. It integrates with your development environments and DevOps pipeline to detect open source libraries with security or compliance issues in real-time.