Screen-based eye tracker capturing gaze data at 120 Hz. This ultra-slim, powerful research system is perfect for studies outside of the lab, and a new generation of eye tracking technology makes it possible to track more people than ever. It is designed for exhaustive, detailed fixation-based research.





Fully-mobile, powerful for detailed research

The Tobii Pro X3-120 is our latest screen-based eye tracker and has a sampling rate of 120 Hz. It features our latest eye tracking technology advancements.

The system 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 more people than ever before, and the discrete form factor promotes unobtrusive data collection.

The 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. The Pro X3-120 is perfect for both qualitative and quantitative research, e.g. calculation of different eye tracking metrics.

The Tobii X3-120 Eye Tracker is available for purchase or rental.


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 and 8.1
  • Supports Mac OS X and Linux using the external processing unit
  • Calibrates subjects quickly and automatically

Captures natural behaviour

Subjects can be tracked while moving their head freely 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 exceptionally-high accuracy and unparalleled tracking capability in real-life conditions ensure high-quality data while allowing you to work with a wide cross-section of your population.

  • Created with the latest technology advancements from Tobii Pro 
  • Delivers exceptionally accurate gaze-position data within the entire tracking box
  • Tracks more people than ever before, regardless of ethnicity or corrective lenses
  • Detects eyes instantly with minimum data loss during blinks or if subjects look away
  • Maintains accuracy and tracking robustness during subjects’ head movements and in ambient light
  • Alternates between bright and dark pupil eye tracking in a predefined, systematic way



System Components



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 2.0, 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).

Technical Specifications

Technical specification

Gaze sampling frequency 120 Hz
Trackability 97%
Tracking robustness 92%
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
Data output (for each eye) Timestamp
Eye position
Gaze point
Pupil diameter
Validity code

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 (with BC 1.2), 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 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
i2 Visualizer Implicit System, Eyesquare
Observer XT , Noldus

For definitions and more detailed specifications, please refer to the Pro X3-120 accuracy and precision test report and to the Pro X3-120 product description.