WorldCache: Accelerating World Models for Free via Heterogeneous Token Caching

TL;DR

WorldCache is a novel caching framework that accelerates diffusion-based world models by predicting and selectively skipping tokens based on their predictability and drift, achieving significant speedups with minimal quality loss.

Contribution

We introduce WorldCache, a caching method tailored for diffusion world models, incorporating curvature-guided token prediction and adaptive skipping to enhance efficiency.

Findings

Up to 3.7× speedup in inference time

Maintains 98% of rollout quality

Effective in resource-constrained scenarios

Abstract

Diffusion-based world models have shown strong potential for unified world simulation, but the iterative denoising remains too costly for interactive use and long-horizon rollouts. While feature caching can accelerate inference without training, we find that policies designed for single-modal diffusion transfer poorly to world models due to two world-model-specific obstacles: \emph{token heterogeneity} from multi-modal coupling and spatial variation, and \emph{non-uniform temporal dynamics} where a small set of hard tokens drives error growth, making uniform skipping either unstable or overly conservative. We propose \textbf{WorldCache}, a caching framework tailored to diffusion world models. We introduce \textit{Curvature-guided Heterogeneous Token Prediction}, which uses a physics-grounded curvature score to estimate token predictability and applies a Hermite-guided damped predictor for chaotic tokens with abrupt direction changes. We also design \textit{Chaotic-prioritized Adaptive Skipping}, which accumulates a curvature-normalized, dimensionless drift signal and recomputes only when bottleneck tokens begin to drift. Experiments on diffusion world models show that WorldCache delivers up to \textbf{3.7$\times$} end-to-end speedups while maintaining \textbf{98\%} rollout quality, demonstrating the vast advantages and practicality of WorldCache in resource-constrained scenarios. Our code is released in https://github.com/FofGofx/WorldCache.