Agreement for PhET’s historical collection of HTML Simulations
For PhET Regular HTML Simulation File versions published prior to March 29, 2026
University of Colorado Boulder
WARNING: You are viewing licensing information linked from an outdated and no longer maintained simulation version. We highly recommend using the latest version accessed from the Simulations page.
Agreement
This PhET Software Agreement (“Agreement”) pertains to the historical collection of PhET Regular HTML Simulation Files (“Historical PhET Simulations”) developed by the PhET Interactive Simulations Project at the University of Colorado Boulder (“PhET”) and released prior to March 29, 2026. Historical PhET Simulations were published under the Creative Commons Attribution 4.0 License (CC BY 4.0).
Limitations
This Agreement and the information on this page does not pertain to:
The Regular HTML Simulation Files (the “PhET Simulations”) published after March 29, 2026,
The Interoperable HTML Simulation Files (the “PhET-iO Simulations”),
The Java or Flash Simulation Files (the “Legacy Simulations”).
For information about these simulations, please visit Licensing.
What does the CC BY 4.0 License mean?
Historical PhET Simulations may be freely used and/or redistributed by third parties (e.g., students, educators, school districts, museums, publishers, vendors, etc.) for non-commercial or commercial purposes.
How can I tell if the simulation I’m using is a Historical PhET Simulation?
When viewing a simulation, click on the PhET menu, then click on the About menu option. This will load the simulation’s About Dialog which provides the version and publication date. Simulations with a publication date prior to 2026-03-29 are Historical PhET Simulations.
Using Historical PhET Simulations in Teaching and Learning
Any students or educators (K-12, university, continuing education, public or private) can use the simulations for free for any non-commercial purposes, including classroom use, homework, student projects, etc. You must appropriately attribute the simulations (see Attribution Requirements). You do not need to seek any further permissions from us.
Using Historical PhET Simulations in Research
Education research guides the design and classroom use of PhET simulations. Not only does the PhET team engage in education research directly, but we love to see PhET simulations being used by researchers worldwide to advance knowledge about teaching, learning, and assessment.
Researchers are encouraged to use PhET HTML5 simulations from https://phet.colorado.edu in their work. No further permission is necessary to use the simulations in research provided two steps are followed:
Provide proper attribution (see Attribution Requirements) when a simulation or any derivative work appears in education materials, presentations, journal articles, websites, or other channels you may use to distribute your work.
For each published article, please complete the PhET Use in Research form to share information about your publication with us.
Researchers interested in customizing simulations or collecting back-end data for use in learning engineering or learning analytics research may be interested in PhET’s interoperable (PhET-iO) simulations. Learn more about PhET-iO.
Attribution Requirements
All Historical PhET Simulations are open educational resources and provided under the Creative Commons Attribution 4.0 License (CC BY 4.0). The following attribution is required when sharing or redistributing a Historical PhET Simulation:
Simulation by PhET Interactive Simulations, University of Colorado Boulder, licensed under CC BY 4.0 (https://phet.colorado.edu).
Additional Attribution Guidelines:
Attribution must appear as close as possible to the point of use and be human-readable
Translations of the attribution text are permitted, other modifications are not permitted
Use Of the PhET Name and Logo
When using the PhET simulations in accordance with the CC BY license, the following use of the PhET brand is required:
In the simulation: The PhET logo must remain visible, unobstructed, and unaltered. It may not be concealed or replaced.
In the attribution text: “PhET Interactive Simulations, University of Colorado Boulder” must be included in full, as well as the URL (https://phet.colorado.edu).
In written references (e.g. research publications or media articles): The first reference should be written as “the PhET Interactive Simulations project at the University of Colorado Boulder.” Subsequent references may be abbreviated to “PhET” or “PhET Project.”
PhET is a trademark owned by the Regents of the University of Colorado, a body corporate, registered in the U.S. and other countries. Any use of the PhET brand or likeness—including the name, logo, icons, or simulations—for promotional, marketing, or advertising purposes requires a separate license agreement. Learn more about Partnerships.
Privacy Policy
The University of Colorado and the PhET Interactive Simulations Project support the protection of individual privacy and ensuring the confidentiality of information provided by its employees, students, visitors, and resource users. See the PhET Privacy Policy.
Support PhET’s Work
PhET Interactive Simulations at the University of Colorado Boulder is a non-profit organization that reaches hundreds of millions of learners globally. Please support PhET with a tax-deductible donation today!
Contact Us
Please send comments, questions, or concerns regarding this software agreement to [email protected].