Prodigy: An Expeditiously Adaptive Parameter-Free Learner
Konstantin Mishchenko, Aaron Defazio
TL;DR
The paper tackles the problem of tuning learning rates in adaptive optimizers by introducing Prodigy, a parameter-free learner that estimates the distance to the solution using AdaGrad-like step sizes. Prodigy modifies D-Adaptation to yield faster non-asymptotic convergence, establishes a lower bound framework for exponentially bounded algorithms, and derives Adam-like step-size variants to extend applicability. Theoretical results show improved rates with a sqrt(log(D/d0)) factor, while extensive experiments across logistic regression, CIFAR-10, transformers, LSTM, and other large models demonstrate consistent performance gains over D-Adaptation and close alignment with hand-tuned Adam. The approach is practical and has already achieved wide adoption in real-world training pipelines, including Hugging Face Diffusers and LoRA-based workflows.
Abstract
We consider the problem of estimating the learning rate in adaptive methods, such as AdaGrad and Adam. We propose Prodigy, an algorithm that provably estimates the distance to the solution $D$, which is needed to set the learning rate optimally. At its core, Prodigy is a modification of the D-Adaptation method for learning-rate-free learning. It improves upon the convergence rate of D-Adaptation by a factor of $O(\sqrt{\log(D/d_0)})$, where $d_0$ is the initial estimate of $D$. We test Prodigy on 12 common logistic-regression benchmark datasets, VGG11 and ResNet-50 training on CIFAR10, ViT training on Imagenet, LSTM training on IWSLT14, DLRM training on Criteo dataset, VarNet on Knee MRI dataset, as well as RoBERTa and GPT transformer training on BookWiki. Our experimental results show that our approach consistently outperforms D-Adaptation and reaches test accuracy values close to that of hand-tuned Adam.
