FAQ (Frequently Asked Questions)


No. StarUML V1 was an open source project under GPL License. However, current StarUML (after V2) is not open source any more. Many users have been expected that the project is being continued, developed and maintained. But, we couldn’t find any sponsors so we can’t avoid to commercialize this product in order to keep developing and supporting users.

Yes. you can use StarUML V1 for any purpose. However, don't forget that the StarUML V1 is no more maintained and cannot be supported.

License is perpetual, so you can use forever with the purchased version. However, you need to pay to upgrade to new major versions.

In evaluation mode, there will be watermarks in the exported diagram images. There is no time limit for evaluation, but it is only allowed for evaluation purpose. If you want to use for other purposes including educational, personal, or commercial purpose, you need to purchase licenses.

Commercial licenses are the standard licensing option for companies. They can be used by anyone working for the company. On the contrary, personal license is the licensing option for a private individual purchasing. See more details about licensing options.

Yes, you can. But your license can not be shared with other colleagues.

Yes. you can install on multiple machines owned by you, but it is not allowed to install on other's machines.

No. Employees should not use a commercial license at home, unless on a work computer or for work purposes. Commercial license cannot be shared with other companies or individuals.

Multi-user license means that you can use a single license key for one or more users. Commercial and classroom license types provide multi-user license while personal and educational license types only provide single license key for only single users.

Multi-user license is NOT floating (concurrent) license.License should be purchased as many as the total number of users (not maximum concurrent user). For example, if there are total 10 users who will use the software in the company, the company have to purchase license for 10 users even if the users will not use the software at the same time.

License Activation

You need check the version of your license key. For example if your license is for V4 or lower, then it will not work for V5 or higher. In this case, you need to upgrade your license to the new version at  on-line store.

To activate license in an off-line computer, please try the following instruction:

  1. Install StarUML and register with license key in an internet-connected computer.
  2. Find "license.key" file in
    • /Users/<user>/Library/Application Support/StarUML for Mac OS.
    • C:\Users\<user>\AppData\Roaming\StarUML for Windows.
    • ~/.config/StarUML for Linux.
  3. Copy the "license.key" to the offline computer you will use at the same path .
  4. Delete "license.key" at the internet-connected computer.


Refunds are available within 30 days of purchasing. Please send us an email (support@staruml.io) if you wish to claim a refund.

You can freely update to minor updates (e.g. to 5.x version), but you may need to pay to upgrade to major upgrades (e.g. to V6 version). Upgrade fee will be much cheaper than purchasing new one.

If you have further questions, please contact us.