A neural network's loss landscape is rarely a smooth bowl — it's rugged, with ridges and shallow valleys. The learning rate controls how big a step the optimizer takes at each iteration across that landscape. Too high, and the ball bounces wildly across ridges without settling; too low, and it crawls so slowly it barely moves. This simulation rolls a ball down a 3D loss surface using real gradient descent, where the step size at each moment is set by the learning-rate schedule you choose — visualized live on the floating curve above the surface.
Cosine annealing with warm restarts (SGDR) was introduced by Loshchilov & Hutter in 2016 and remains one of the most widely used schedules in modern deep learning, including in training large transformer models.
A ball performs live gradient descent across a rugged 3D loss surface, its step size at every moment set by the learning-rate schedule you choose, while a floating curve plots the schedule and the resulting loss over the run.
How the shape of a learning-rate schedule — constant, step decay, cosine annealing, warmup, or exponential decay — changes the path an optimizer takes: whether it overshoots, oscillates, or settles smoothly into a minimum.
Pick a schedule, base learning rate, total steps, and warmup length. Watch the ball descend the landscape in real time and compare the purple LR curve against the teal loss curve above the surface.
Cosine annealing with warm restarts (SGDR), introduced by Loshchilov & Hutter in 2016, is one of the most widely used schedules in modern deep learning, including large transformer training runs.