Backpropagation

The chain rule, one layer at a time
2-4-4-1
Or use the /+ under any layer on the canvas, and the + in the gaps between them. Weights survive the resize.
0.500
1
One sample — the numbers you see are the update.
2.0 /s
Phases per second.
positive weight
negative weight
forward signal  a
backward gradient  δ
Ready
Press play to run a training step.
 
 
iteration0
epoch0.00
loss (dataset)
accuracy
parameters
cross-entropy vs. iteration
what the network has learned
Chain rule for
 
Click a weight to trace its chain rule  ·  /+ under a layer to resize  ·  Space play/pause  ·  S step  ·  R reset