Anthropic and pretraining

Claude models

Pretraining data cutoff dates

See the fog app for an interactive view of models’ epistemic horizons.

(table)

Methods

• Decontamination

Methods

• Modular Pretraining (GRAM)

Data filtering

• Classifier-based data filtering¹
• Canary strings

External links

• https://www.google.com/search?q=%22continued+pretraining%22+site%3Aanthropic.com

Discussion

• Anthropic’s focus on hyperstition (Simon Lermen, May 11, 2026)