Wave Interference Simulator
Two wave sources create constructive and destructive interference patterns.
Pick Two sources or Slits. Drag the water drippers (or the barrier) and change wavelength, separation, slit width and phase. Bright and dark bands appear where waves add or cancel. Drag the little probe to read the wave height, and switch between water, sound and light colours.
About the Wave Interference Simulator
Free wave interference simulation. Move two wave sources, change frequency and see constructive and destructive interference patterns like a real ripple tank. Built for physics, the wave interference simulator runs instantly in your browser: change a setting or drag an object and the result updates at once, so you learn by trying things out rather than only reading about them.
Two wave sources create constructive and destructive interference patterns. Use it to explore physics ideas at your own pace, then check what you found against the key ideas further down this page.
How to use the Wave Interference Simulator
- Use the controls to change Medium, Wavelength, Source / slit separation, Slit width, Phase difference, and more. The simulation reacts instantly.
- Pick an option such as Two sources, Slits, Water, Sound to switch modes or load an example.
- Press "Pause / play" to start, reset or change what is happening.
- Where you see a glowing handle, object, weight or atom, drag it with your mouse or finger. Everything responds in real time.
- Watch the readouts and graphs update as you experiment, and compare what you see with the key ideas below.
Things to try
- Set the phase difference to 180° and watch the pattern flip.
- Increase the source separation and count the lines.
- Switch to one source and compare.
- Change the wavelength and see how the fringes move.
Key ideas you can learn
- Where crests meet crests the waves add up: constructive interference.
- Where crests meet troughs they cancel: destructive interference.
- Higher frequency means shorter wavelength and more interference lines.
Where this is used in the real world
Noise-cancelling headphones, radio antenna arrays, ripple tanks and concert-hall design all rely on wave interference. Fishermen and engineers also use it to understand harbour waves.
Who is this simulation for?
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. It works well for flipped classrooms because students can explore before the lesson.
For teachers: project it on the board, let students predict what will happen, then run it together. For students: change one thing at a time and write down what changes.
Frequently asked questions
What is constructive interference?
It happens when two waves are in phase and add together to make a larger wave. In the simulator these are the bright bands.
What is destructive interference?
It happens when waves are out of phase and cancel. In the simulator these are the dark bands where the water stays still.
Is the Wave Interference Simulator free to use?
Yes. It is completely free, with no signup, no download and no ads inside the simulation. It runs in your web browser.
Does the Wave Interference Simulator work on a phone or tablet?
Yes. It uses touch as well as the mouse, so you can drag objects with your finger. A larger screen makes the controls easier to see.