C2: Backpropagation Walkthrough

Step through the Chain Rule to see how error gradients flow backward through the network.



Ready. Click "Run Forward Pass" to begin.
Local Gradients
σ(z)σ(1-σ)
y = w·x∂y/∂w = x
y = Σxᵢ∂y/∂xᵢ = 1
L = ½(t-y)²∂L/∂y = y-t
Network State
Current Calculation
∂L/∂w = ...
...
Waiting to start...
Forward Signal (Activation)
Backward Gradient (Error)
Bias Terms
Weights