The L1 Loss Gradient, Explained From Scratch

Last Updated on April 10, 2026 by Editorial Team Author(s): Utkarsh Mittal Originally published on Towards AI. A complete, step-by-step walkthrough of how gradient descent works with absolute-value loss — with diagrams you can actually follow. If you’ve ever read a deep learning tutorial and hit a derivative that seems to appear from nowhere, this article is for you. We’re going to break down one of the simplest — yet most instructive — gradient calculations in machine learning: the gradient of