PhET Interactive Simulations


PhET provides fun, free, interactive, research-based science and mathematics simulations. We extensively test and evaluate each simulation to ensure educational effectiveness. These tests include student interviews and observation of simulation use in classrooms. The simulations are written in Java, Flash or HTML5, and can be run online or downloaded to your computer. All simulations are open source. Multiple sponsors support the PhET project, enabling these resources to be free to all students and teachers.

To help students engage in science and mathematics through inquiry, PhET simulations are developed using the following design principles:

  • Encourage scientific inquiry
  • Provide interactivity
  • Make the invisible visible
  • Show visual mental models
  • Include multiple representations (e.g., object motion, graphs, numbers, etc.)
  • Use real-world connections
  • Give users implicit guidance (e.g., by limiting controls) in productive exploration
  • Create a simulation that can be flexibly used in many educational situations

Several tools in the simulations provide an interactive experience:

  • Click and drag to interact with simulation features
  • Use sliders to increase and decrease parameters
  • Choose between options with radio buttons
  • Make measurements in your experiments with various instruments – rulers, stop-watches, voltmeters, and thermometers.

As users interact with these tools, they get immediate feedback about the effect of the changes they made. This allows them to investigate cause-and-effect relationships and answer scientific questions through exploration of the simulation.


Plan Price Details
PhET Interactive Simulations Free Free use of all interactive simulations.


Math and Science teacher
July 4, 2015

Great tool for students to explore and learn new concepts

February 23, 2012

Agree. Some of the simulations even lend themselves well to a simulated experiment in which a student can track (usually by hand or on a separate spreadsheet) how a dependent variable is effected by an independent variable.

February 22, 2012

Some simulations are higher quality than others, but overall PhET simulations are a fantastic way for students to explore scientific concepts. These can be used in an open-ended, exploratory way (Play around with the "skateboard simulation" and tell me what you learned) or in a more focused, teacher-directed way.

One small caveat, some simulations don't work well on netbooks with low-resolution screens (1024 x 600).