Explore the Doppler Effect Simulator
Move a sound source and an observer and hear how the pitch changes with speed. Free, no signup, runs in your browser.
- Free to use
- No signup
- Nothing to install
- Runs in your browser
Illustration. Open the tool for the real thing.
See it in action
The Doppler Effect Simulator with sample data entered and the result showing.
What is the Doppler Effect Simulator?
Move a sound source and an observer and hear how the pitch changes with speed. It runs in your browser, so a change to a setting or a drag on an object shows up at once.
The Doppler effect is used in police speed radar, weather radar, medical ultrasound and to measure the expansion of the universe.
3 steps to your result
Open the tool and follow along. Nothing to install.
What you get
A source moving toward you squeezes the waves together, so you hear a higher pitch.
Moving away stretches the waves, so the pitch is lower.
At the speed of sound the wavefronts pile up into a shock wave (Mach cone).
Increase the source speed and watch the fronts bunch up ahead of it.
Drag the observer in front of and behind the source.
Push the speed above Mach 1 to make the cone.
Used for
Pick one to see how it fits.
Physics learners
Physics students in middle school, high school and first-year university, teachers who want a quick demonstration for the projector, and anyone revising for exams.
Try it freeTeachers
For teachers: project the Doppler Effect Simulator on the board, let students predict the result, then run it together and test this: Drag the observer in front of and behind the source. For students: change one thing at a time and write down what changes.
Try it freeHow it compares
A plain look at this tool next to the usual alternative.
| This simulation | Textbook diagram | |
|---|---|---|
| Interactive | Drag, tap and change settings | Fixed picture |
| Install | Nothing to install | Not needed |
| Cost | Free to use | Depends on the book |
Questions people ask
What is the Doppler effect?
The change in observed frequency when the source or the observer is moving. Approaching raises the pitch, receding lowers it.
What is a sonic boom?
When a source moves faster than sound, the wavefronts overlap into a cone-shaped shock wave. An observer hears a sudden, very loud boom when it passes.
Is the Doppler Effect Simulator free to use?
Yes. The Doppler Effect Simulator is free, needs no signup or download and runs in your web browser. It is part of the Physics group of AZRS simulations.
Does the Doppler Effect Simulator work on a phone or tablet?
Yes. The Doppler Effect Simulator takes touch input as well as mouse input, so you can use its 2 adjustable settings with a finger. A larger screen makes the controls and graphs easier to read.
How do I use the Doppler Effect Simulator?
1. In the Doppler Effect Simulator, use the controls to change Source speed, Sound frequency. The simulation reacts instantly. 2. In the Doppler Effect Simulator, pick an option such as Still, Car, Almost Mach 1, Supersonic jet to switch modes or load an example. 3. In the Doppler Effect Simulator, press "Hear observer A", "Pause" to start, reset or change what is happening. 4. Start with this experiment: Increase the source speed and watch the fronts bunch up ahead of it. Drag any glowing handle, object or slider with your mouse or finger and the Doppler Effect Simulator responds in real time. 5. Change one setting at a time and watch which readout moves, then compare it with this idea: A source moving toward you squeezes the waves together, so you hear a higher pitch.
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Try the Doppler Effect Simulator now
Move a sound source and an observer and hear how the pitch changes with speed. Free to use.
Try it free