Demo Instructions:
For the Input (blue) or Filter (purple), draw signals with your mouse or choose presets from the dropdown menus.
The "R" color bar on the right shows the correlation strength.
The bottom graph shows the filtered Output (red) which is (like) the convolution of the Input and Filter.*

Choose Input signal: Choose Filter signal: R

Autoscale (If Output goes off-screen, press "Autoscale")

Suggested Exercises:

Set or draw Input & Filter (nearly) the same, observe R.
Set Input to Noisy Sine, Filter to LPF or HPF
Play around and see what you can learn!

*Technically it's the cross-correlation, which is the convolution up to a minus sign.