# NASA TLX

> Digital tool for measuring subjective workload using a multi-dimensional rating procedure. (iPhone/iPad app by NASA.)

- Source: https://appshunter.io/ios/app/nasa-tlx/id1168110608 (this page in markdown: same URL + `.md`)
- Developer: [NASA](https://appshunter.io/developer/355542146)
- Category: Productivity, Utilities
- Price: Free
- Rating: 3.50/5 from 11 App Store ratings · 7 written reviews indexed
- Age rating: 4+
- Requires: iOS 10.0 · 17 MB
- Languages: American English
- Released: 2017-02-15
- Data updated: 2026-08-16
- Monetization: free
- User reviews in markdown: https://appshunter.io/ios/app/nasa-tlx/id1168110608/reviews.md

## What is NASA TLX?

The Official NASA Task Load Index (TLX) App, widely regarded as the gold standard for measuring subjective workload across a wide range of industries, enables researchers to easily perform assessments on operators working with various human-machine interface systems.

By incorporating a multi-dimensional rating procedure, the NASA TLX derives an overall workload score based on a weighted average of ratings on six sub scales:

∙ Mental Demand
∙ Physical Demand
∙ Temporal Demand
∙ Performance
∙ Effort
∙ Frustration

Originally developed as a paper and pencil questionnaire by NASA Ames Research Center’s (ARC) Sandra Hart in the 1980s, the NASA TLX is the benchmark against which the efficacy of other measures, theories, or models are judged. The NASA TLX has been successfully used around the world to assess workload in various environments such as aircraft cockpits; command, control, and communication (C3) workstations; supervisory and process control; and simulations and laboratory tests.

The NASA TLX app for iOS dramatically increases the outreach and accessibility for the research and development community, and enables mobile and contextual assessments (e.g., in an airplane cockpit during/after flight, rather than at a desktop computer in a lab). It offers several key features that benefits both researchers and participants:

Privacy
The NASA TLX has been designed to ensure the privacy of research participant data. The NASA TLX anonymizes all results and does not send any personal identifiable information (PII) to any data servers.

Location Flexibility
The 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. The NASA TLX results are calculated on the device, and, once a network connection is available, collected data can be securely uploaded to servers for analysis. This frees researchers from being burdened by the task of tracking individual paper forms.

Simple Study Setup
Researchers can set up studies quickly and reduce typing on the 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.

## Key features

- Subjective workload measurement
- Six sub-scale rating procedure
- Anonymized data collection
- Offline assessment capability
- QR code study setup
- Location flexibility

## Recent user reviews (7 of 7)

All indexed reviews: https://appshunter.io/ios/app/nasa-tlx/id1168110608/reviews.md

### 1/5 — Keeps Crashing

*2025-12-04*

When I click „Start“ or „Settings“ the app crashes on my iPhone 15 with iOS 26.1.

### 3/5 — Useful but Flawed

*2024-12-12*

Works well for intended use although consistently crashes after reviewing results, and sorts files in no particular order.

### 1/5 — Application will not open

*2024-06-09*

This app does not work proberly!

### 1/5 — Glitchy

*2024-05-01*

App crashes every time I hit “get started”

### 1/5 — Slow

*2023-03-24*

Getting invalid results from an app that is not responding to taps. Users are frustrated and randomly tapping and not completing the survey.

### 1/5 — When trying to share data app freezes

*2021-03-01*

Whenever I try to export data to either my email or  a file in my phone the app freezes. Also, there is no way of selecting multiple files to export

### 5/5 — Great app helps our research

*2020-03-01*

This is a truly great app to help us assess the workload in a easier and faster way. Just one complaint: would you please rearrange the results history so that I could find my results quicker. The current arrangement seems to be randomized.

## Frequently asked questions about NASA TLX

### What is NASA TLX used for?

NASA TLX is used to measure subjective workload across a wide range of industries. It helps researchers assess the mental, physical, temporal demands, performance, effort, and frustration experienced by operators working with human-machine interface systems.

### How does NASA TLX ensure user privacy?

NASA TLX anonymizes all results and does not send any personally identifiable information (PII) to data servers. This ensures that research participant data remains private and secure.

### Can NASA TLX be used offline?

Yes, NASA TLX can be used anywhere, even without a network connection. This allows researchers to conduct evaluations in the field, and data can be securely uploaded once a network connection is available.

### How quickly can researchers set up studies with NASA TLX?

Researchers can set up studies quickly by scanning a pre-generated QR code within the app. This automatically populates the study name, subject ID, and trial number, reducing typing effort.

### What platforms is NASA TLX available on?

NASA TLX is available for iOS devices, including iPhone, iPad, and iPod. It is designed to increase outreach and accessibility for the research and development community.

### What is the update frequency for NASA TLX?

The latest version of NASA TLX is 1.0.3, which was last updated on September 18, 2018. While not frequently updated, its core functionality remains stable for its intended research purpose.

### What is the age rating for NASA TLX?

NASA TLX has an age rating of 4+. This indicates it is suitable for users aged 4 and above, making it accessible for a broad range of participants in research studies.

### Does NASA TLX have ads?

No, NASA TLX does not contain advertisements. As a free application developed by NASA, it focuses on providing a research tool without commercial interruptions.

## Version history (last 4 releases)

### 1.0.3 — 2018-09-18

- Requires iOS 10.0 or greater
- Added the ability to launch the NASA TLX app from other NASA research apps
- Minor iPad layout issue fixes

### 1.0.2 — 2017-07-18

Added in the ability to access the documents folder for NASA TLX from Apple iTunes. This allows researchers to transfer large sets of collected data from the NASA TLX app without having to use the single file sharing option. Simply connect the iOS devices used to collect data on to a Mac or Windows computer, launch iTunes, navigate to the app section for the iOS device in iTunes, and find the app, and select the documents folder. You should now be able to transfer the collected research data from the app to your computer.

### 1.0.1 — 2017-05-17

- Fixes a problem for some iPad users trying to share research data using the built in sharing mechanism.
- Fixes an issue where the subjective scale bar on iPads might move beyond the end of the indicated scale.
- Adds a version number display to the About TLX page.

### 1.0.0 — 2017-02-15

No release notes.

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## Related topics

[nasa tlx](https://appshunter.io/ios/topics/nasa-tlx)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-16.*