The Tobii Gaze SDK and Tobii EyeX SDK may have similar names, but there are many differences that are good to know about when deciding which of them to use when developing your application or game.

Let’s start with the Gaze SDK, which provides low-level APIs for accessing eye tracking data. Being low-level means that it is easy to port to different operating systems and gives you full control of how to mount the eye tracker and how to process and use the data. But this also means that you need to do a lot of configuration, calibration and data processing by yourself. Moreover, if you want to run your application in an environment where other applications also are using the eye tracker, there might be interference and conflicts between the applications. In general we only recommend the Tobii Gaze SDK if you have control of the entire system, for example in an embedded or single-application environment. The Gaze SDK is available for Windows, Linux, and Android.

If you instead use the EyeX SDK, you make use of the EyeX Engine API which makes it easier to get started and create applications that make use of high-level interaction events in addition to the low-level data from the eye tracker. The EyeX Engine takes care of calibration, screen setup and can map user input triggers to events that are related to the object the user is looking at. In an environment where many applications want to use the eye tracker to drive the user interface, the EyeX Engine helps to mediate between the applications and create a user experience that is consistent across the operating system. The downside with the EyeX SDK is that is, until these services are built into the operating system, requires a running background process. Since many of the features are dependent on services exposed by the operating system, it also makes the EyeX SDK hard to port to different operating systems. Right now it is only available for Windows.

The licensing terms is another area where the two alternatives differ: the EyeX SDK licensing terms are much more permissive. (Note that these are the “default” licensing terms given to everyone. It’s of course also possible to contact us directly if you want to discuss other licensing terms.)

In short, you could describe the two SDK alternatives like this:

  • Tobii Gaze SDK: Access library for Tobii eye trackers.
  • Tobii EyeX SDK: OS extension for interaction using Tobii eye trackers.

Hardware Support for Gaze software SDK:
Windows – Tobii EyeX
Linux & Android: Tobii REX