Tobii Pro X3-120 - Discontinued

Screen-based eye tracker capturing gaze data at 120 Hz. This unobtrusive, robust research system is perfect for studies outside of the lab. It is designed for exhaustive, detailed fixation-based research.


Fully-portable, powerful for detailed research

The Tobii Pro X3-120 provides exceptional flexibility and accommodates a wide array of human behavior studies. The ultra-slim, light design makes for a compact solution, ideal for studies in authentic research environments. The Pro X3-120 is capable of tracking almost anyone, and the discrete form factor promotes unobtrusive data collection.

The screen-based system shows exactly where people are looking and, with a sampling rate of 120 Hz, it is designed for detailed research into the timing and duration of fixations.

A person in front of a PC with Tobii Pro X3-120 mounted on it.

Versatile for a broad spectrum of studies

The Pro X3-120 can be used with a variety of screens – laptops, PC monitors, tablets, or TVs.

The system can be mounted on screens up to 25" in size. We offer accessories in order to make research with mobile devices easier. The Pro X3-120's high-quality tracking of large gaze angles (up to 36°) allows you to also study large projections.

There are additional accessories to accommodate studies of real-world stimuli, such as physical objects or people.

Easy to use

Simple setup, configuration, and automation promote efficient eye tracking studies.

  • Attaches easily with supplied mounting solutions for various screens
  • Works in a controlled environment using the supplied external processing unit or connects directly into your PC (using a USB 3.0 cable)
  • Simple configuration for Windows 7, 8.1 and 10.
  • Supports Mac OS X and Linux using the external processing unit
  • Calibrates subjects quickly and automatically

“Eye tracking is invaluable in our research to gain deep insights into information acquisition and preference formation in marketing communication and consumer decision-making processes. The new Tobii Pro X3-120 tracks more people than any other system we’ve seen to date. With this extremely robust and highly-mobile solution, we can study more consumers more efficiently and get more data of high quality. This is a major step forward.”

Rik Pieters, Professor of Marketing, School of Economics and Management at Tilburg University, the Netherlands

Captures natural behavior

Participants can be tracked while moving their head positioned at a natural distance from the screen, and the device is hardly noticed. This creates a distraction-free test environment, promoting natural human behavior.

  • Tolerates a variety of head movements
  • Collects highly-accurate data at close distances, such as a laptop, to longer distances, such as an ATM
  • Blends perfectly into the research environment with its ultra-slim, discreet design
  • Stable and reliable eye tracking calibrations eliminate the need for recalibration

Accurate and robust tracking

The system's very high accuracy and vast tracking capability in real-life conditions ensure high-quality data, while allowing you to work with a wide cross-section of your population.

  • Delivers exceptionally accurate gaze-position data within the entire tracking box
  • Extremely robust tracking capabilitie, regardless of ethnicity or corrective lenses
  • Detects eyes instantly with minimum data loss during blinks or if subjects look away
  • Tolerance for head movements and varied lighting condition
  • Alternates between bright and dark pupil eye tracking in a predefined, systematic way

"The Tobii Pro X3-120 enables new possibilities for eye tracking in educational settings due to it's small size and large tolerance to head movements."

Gustaf Öqvist Seimyr, PhD, Senior Researcher, Optolexia

"For us, it’s almost impossible to run tests in a lab. I want to see the user in their natural environment. With screen-based eye tracking, I’m not bound to a specific area or location, but can perform tests wherever I want."

Tor Hauksson, Interaction Designer, Cloud Nine, Sweden


Eye tracker unit

The eye tracker unit measures only 324 mm (12.7'') in length and weighs 118 g (4.2 oz.). It attaches onto screens up to 25" (16:9) with supplied adhesive mounting brackets for monitors, laptops, and tablets.

Mounting solutions for the study of mobile devices, as well as brackets for larger projections or real-world objects (up to a 36° gaze angle), are offered as accessories. With provided adapters, the Pro X3-120 can use the same mounting brackets that come with other screen-based eye trackers from Tobii Pro.

External processing unit

Gaze data calculations are performed by firmware on an external processing unit (using USB 3.0, LAN, and a power connector). This gives you a controlled environment for running your tests with dedicated eye tracking processing, and the ability to use Mac or Linux, as well as computers with lower performance. The external processing unit also enables multiple connections to the Pro X3-120, for example in E-Prime two-computer setups.

Alternatively, calculations can be done by a host processed on your PC (using USB 3.0).


Eye tracking specifications

Gaze sampling frequency 120 Hz
Accuracy 0.4°
Precision 0.24°
Freedom of head movement

Width x height: 50 cm x 40 cm (19.7″ x 15.7″) @ 80 cm operating distance: 50 – 90 cm (19.6″ – 35.4″)

Latency Total system latency: < 11 ms
Gaze recovery time

For blinks: immediate
After lost tracking <100 ms

Recommended screen size Up to 25ʺ (16:9)
Tracking technique Binocular, dark and bright pupil tracking combination. One camera system.
Data output (for each eye) Timestamp
Eye position
Gaze point
Pupil diameter
Validity code

* Tobii Pro uses an extensive test method to measure and report performance and quality of data. Please download the data quality test report for more detailed information.

Eye tracker unit

Size 324 x 20 x 17 mm (12.7 x 0.8 x 0.7″)
Weight 118 g (4.2 oz)
Eye tracking processing On local windows PC or External Processing Unit (accessory)
Connectors USB 3.0, LAN with External Processing Unit (accessory)
Mounting alternatives Adhesive mounting brackets for monitors, laptops and tablets. Desk stand accessory package for tripods and desks.

Software compatability

Tobii Pro Lab
Tobii Pro Studio 3.2.2 or later
Tobii Pro Analytics SDK 3.0.98 or later
Other applications built on the Tobii Pro Analytics SDK 3.0.98 or later
Attention Tool, iMotions
E-Prime Extensions for Tobii Pro 3.2, Psychology Software Tools (PST)
i2 Visualizer Implicit System, Eyesquare
Observer XT , Noldus


Our eye trackers combine excellent accuracy and precision with an extremely high tolerance for large head movements and a variety of environments. Read more


We have developed a test method to make it possible to compare different eye tracking systems. Repeat the tests by using the test specifications and judge the quality of the products yourself. Read more

How do Tobii Eye Trackers work?

In this section we will describe how an eye tracker works. Read more

Learn & Support

Related Products

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Mobile Device Stand
Mounting solution for mobile device testing using Tobii Pro X2-30, X2-60 or X3-120 eye tracker. Works with phones, tablets and other similarly sized devices. Read more

Related Services

Tobii Pro help you get started with online training. This two-hour session will help you to install and learn how to operate your eye tracking system. Read more
Tobii Pro offers onsite installation of your eye tracking system. This one-day training provides a basic understanding of the hardware and the software. Read more

Fields of Use

Psychology and Neuroscience

Eye tracking is used in different fields of psychology and neuroscience to understand how and why eye movements are made and how we gather information with our eyes. Read more