While the evaluation version is functional, professionals often opt for the official license for three main reasons: Ethics & Support

: Input the Name and License Key provided in your purchase confirmation email.

, modern versions starting from V2 have transitioned to a proprietary, commercial model. This change was driven by the need for consistent maintenance, updates, and professional support that community-driven models often struggle to sustain. Today, StarUML offers a perpetual license—meaning you pay once and own that specific version forever—rather than a recurring subscription. Evaluation vs. Licensed Use For new users, the StarUML Evaluation Period

99.9% of those are fake. They either do nothing or are old keys from 2014 that the StarUML blacklist has banned.