You can open the License Manager from the Help menu. The license manager allows you to activate and deactivate DiffPlug with one or more licenses, and also to modify which licenses are included in an activation.

license manager

We should first define some terms:

  • A license entitles you to operate a specific premium DiffPlug feature (such as dp.simstate.differ).
  • An activation represents the binding of a license (or licenses) to a specific user on a specific computer.
    • A hardware activation is bound to the hardware of your computer - to the computer’s serial number. It is a permanent activation for the current user on this computer. It lasts until you deactivate it. It may be invalidated if the computer’s hardware changes too much from the license.
    • A web activation is bound to a running instance of DiffPlug. Every few minutes, DiffPlug will call home to the licensing server. It will be automatically deactivated when the program closes or the web connection is lost, or it can be manually deactivated.
    • A single license can be simultaneously bound to one hardware and one web activation. This allows you to bind a license to your primary computer using its hardware activation, but still gives you the flexibility to simultaneously use the same license on other computers (such as while helping a colleague at her desk) by using the web activation.

The left side of the license manager is dedicated to the hardware activation. The right side is dedicated to the web activation. A single instance of DiffPlug can have both a hardware and a web activation simultaneously. This allows you to use your licenses (as a web activation) while working on a colleague’s computer who has already activated some licenses in his hardware activation.

The top of each activation’s pane lists the:

  • id number
  • date it was created
  • DiffPlug account which created it
  • version of DiffPlug which was licensed

Below this is the “health” of each activation. The hardware activation displays the various serial numbers it is bound to, and presents a warning if any of the licensed hardware has changed. The web activation displays the time of the last and next checkins, as well as the time at which the activation will be automatically cancelled if the connection is lost.

Activating, Modifying, and Deactivating

  • To create a new activation, click the Activate button.
  • To change an existing activation, click the Modify button.
    • This is useful not only for changing licenses, but also to upgrade an activation to a newer version of DiffPlug.
  • To unbind all licenses from an activation, click the Deactivate button.

Activate and Modify

When creating or modifying an activation, you will be prompted for your username and password (which can be supplied by the KeyRing). Once you have entered these, click Login to get a list of licenses which are available for activation.

activate dialog before login

Next, place checkmarks next to the licenses which you would like to bind to this activation. You can click the Refresh button to recheck which licenses are available, in case new licenses have been added since you last logged in. Once you have checked all of the licenses you want, click the Activate button.

activate dialog after login


If you want to unbind all of the licenses currently bound to a given activation, click the Deactivate button. After entering your credentials and hitting Deactivate, these licenses will be available in your account for use elsewhere.

deactivate dialog

Using the web interface

You can access a full history of your licenses and activations using DiffPlug’s web interface. The Licenses page shows all of your licenses and the Activations page shows all of your activations. These are also accessible from the Licensing dropdown menu on DiffPlug’s homepage.

web menus

To take a specific example, the screenshots above are for activation id 156. If we click the blue hyperlinked 156, it will take us to, where we can see the activation in the web interface. Note that this particular URL won’t work for you, because you aren’t [email protected]

activation web interface

At the bottom of this page, we can see a table of the licenses which are bound to this activation. If we click the blue hyperlinked 140, it will take us to, where we can see this license in the web interface. Again, this URL will only work for [email protected]

license web interface

The web interface lets you

  • examine your activation history
  • view the purchasing history of a license, including all purchase orders related to it
  • change the administrator and end user of a license for a corporate IT environment

For more information on how administrators and end users work in DiffPlug, check out the licensing for teams page.