Backpropagation Through Time (BPTT) — The Backpropagation Method for Training Recurrent Neural Networks by Unrolling Them Across Time

Backpropagation Through Time (BPTT) is the backpropagation method used to train recurrent neural networks by unrolling them across the time axis and sending the final error backward to earlier time steps while learning a shared set of parameters. It is the core training procedure that allows an RNN to learn context and temporal dependencies in sequential data.

04/02/2026