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Anthropic Transparency Report

Secondary report Stanford University Center for Research on Foundation Models (CRFM)
Accessed: 2026-05-07
Original source ↗

Summary

An evaluation of Anthropic's transparency regarding the development of Claude 4, scoring the company on data acquisition, compute usage, and model architecture disclosures.

Key quotes

Claude Opus 4 and Claude Sonnet 4 were trained on a proprietary mix of publicly available information on the Internet as of March 2025, as well as non-public data from third parties

This report is part of the Foundation Model Transparency Index (FMTI) 2025. it assesses Anthropic’s disclosures across 35 indicators, noting a high reliance on proprietary claims to withhold specific data and compute details.