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A new NASA app is now available that helps researchers evaluate their workloads, on the go.

NASA’s Ames Research Center in California’s Silicon Valley, released on¬†Wednesday February 15, the Official NASA Task Load Index (TLX) app, a new free to download iOS application in the Apple App Store, for use on iPhones and iPads.

The NASA TLX iOS app is available for immediate use by any person or organization (worldwide). It is not necessary to obtain permission from NASA to use the TLX iOS app.

NASA TLX on the iPad and iPhone

Since the 1980’s, the gold-standard subjective workload assessment tool was pencil and paper questionnaires to conduct assessments of workload scores on Mental Demands, Physical Demands,¬†Temporal Demands, Own Performance, Effort, and Frustration. The legacy version, available only on Windows NT/XP desktop computers, is in the top 5 software downloads for the agency, and the top software download for Ames Research Center with an average of 1-3 download requests per week.

"The Official NASA TLX app addresses a significant backlog of pent up demand from researchers looking for a workload measurement solution that integrates with their modern computer/research environments," said Dr. Brian Gore, Deputy Element Scientist for the Human Factors and Behavioral Performance (HFBP) Element in the Human Research Program (HRP) and TLX project lead at Ames. "Now, users will be able to use their mobile devices (iPhone, iPad, and iPod touch) to collect subjective assessments of workload in a given operational context on a very easy-to-use platform."

Click to download the Official NASA TLX iOS App from the Apple App Store

NASA TLX iOS App User Guide (PDF Format - 1.4MB)

TLX iOS App Overview Header

NASA_TLX_App_Preview_720p from Phil So on Vimeo.

Empowering researchers to quickly set up, capture and analyze workload measurement results

Being able to administer and record NASA TLX evaluations using a software app makes it easier than ever for researchers to set up, capture, and analyze NASA TLX results over the original pencil and paper version. Additionally, the app features the following benefits for researchers:

- flexibility in configuring studies and specifying participant population size
- automatic tracking of results, organized by research study
- ability to administer and record NASA TLX results without requiring network connectivity

Mobile App Background

We took a human-centered design approach when developing the NASA TLX app. Observing how the paper and pencil version of NASA TLX was used in research studies led us to carefully consider how to best preserve the original version while implementing features to best support the needs of researchers in a mobile environment.

NASA TLX mapping process from paper and pencil tool to the mobile app.


NASA TLX has been designed to ensure the privacy of research participant data. NASA TLX results are anonymized and no personally identifiable information (PII) is sent to any of the data servers used by NASA TLX.

Location Flexibility

The Official NASA TLX app can be used anywhere, even without a network connection, so researchers can have participants complete a NASA TLX evaluation in the field, outside the confines of a desktop office environment. NASA TLX results are calculated on the device, and, once a network connection is available, these data are securely uploaded to servers for analysis. This frees researchers from being burdened by the task of tracking individual paper forms or calculating workload scores manually.

Simple Study Setup

You can set up studies quickly and reduce typing on the Official NASA TLX app by scanning a pre-generated QR code from within the app, which automatically populates the study name, subject ID, and trial number in the app.

System Requirements and Availability

The NASA TLX app is supported on iPhone, iPad, and iPod touch running iOS 9 or later.
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Curator: Phil So
NASA Official: Brian Gore
Last Updated: October 5, 2023