Frequently Asked Questions


Is StarUML open source?

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.

Can I still use StarUML V1?

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 or time limited?

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

What is the difference between evaluation and purchased license?

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.

Can I use my license at work and at home?

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

Can I use my license on 2 different machines at the same time?

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

Can I use company's license at home?

No. Employees should not use the company's license at home, unless on a work computer or for work purposes. License cannot be shared with other companies or individuals.

License is floating (concurrent)?

No. License should be purchased 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

'Invalid license key' is shown. What's wrong?

You need to compare the version of the installed StarUML (See the About Dialog) with the version of your license key.

For example if your license is for V5 or lower, then it will not work for V6 or higher. In this case, you need to upgrade your license to the new version at on-line store.

How to activate license key in off-line computers (without internet connection)?

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.


Can I get a refund?

Refunds are available within 30 days of purchasing. Please send us an email ([email protected]) if you wish to claim a refund.

Should I pay to update or upgrade to newer versions?

You can freely update to minor updates (e.g. to 6.x version), but you may need to pay to upgrade to major upgrades (e.g. to V7 version). Upgrade fee will be much cheaper than purchasing new one.

If you have further questions, please contact us.