Chronos-Bolt (Base)

Chronos-Bolt Base is the larger, high-accuracy checkpoint in Amazon's Chronos-Bolt family, at 205M parameters. The official model card positions it as more accurate than the original Chronos-Large while remaining dramatically faster, making it the quality tier of the Bolt line and well suited to longer-horizon forecasting.

That combination comes from the shared Bolt design: a patch-based T5 encoder-decoder that produces direct multi-step quantile forecasts over patchified history instead of autoregressive token-by-token rollout. Predicting the whole horizon at once is what keeps it fast despite the larger parameter count. It is pretrained on nearly 100B time-series observations drawn from large public corpora and synthetic pretraining data, as documented by the official Chronos-Bolt model cards.

On TSFM.ai, choose Base when you want a stronger quality ceiling than the smaller Bolt checkpoints without moving to the older autoregressive Chronos-T5 stack. Drop to Chronos-Bolt Small, Mini, or Tiny when latency and cost per series outweigh peak accuracy, or move to Chronos-2 when you need covariates or multivariate cross-learning rather than fast univariate forecasting.