The 2025 Foundation Model Transparency Index

TL;DR

The 2025 Foundation Model Transparency Index assesses and quantifies the transparency practices of major foundation model developers, revealing a decline in transparency scores and highlighting areas needing policy intervention.

Contribution

This paper introduces a new version of the Foundation Model Transparency Index with expanded indicators and evaluates the transparency of key companies, revealing a decline in overall transparency scores from 2024 to 2025.

Findings

Transparency scores decreased from 58 to 40 between 2024 and 2025.

IBM scored the highest with 95, while xAI and Midjourney scored the lowest at 14.

Most companies are opaque about training data, compute, and post-deployment impact.

Abstract

Foundation model developers are among the world's most important companies. As these companies become increasingly consequential, how do their transparency practices evolve? The 2025 Foundation Model Transparency Index is the third edition of an annual effort to characterize and quantify the transparency of foundation model developers. The 2025 FMTI introduces new indicators related to data acquisition, usage data, and monitoring and evaluates companies like Alibaba, DeepSeek, and xAI for the first time. The 2024 FMTI reported that transparency was improving, but the 2025 FMTI finds this progress has deteriorated: the average score out of 100 fell from 58 in 2024 to 40 in 2025. Companies are most opaque about their training data and training compute as well as the post-deployment usage and impact of their flagship models. In spite of this general trend, IBM stands out as a positive outlier, scoring 95, in contrast to the lowest scorers, xAI and Midjourney, at just 14. The five members of the Frontier Model Forum we score end up in the middle of the Index: we posit that these companies avoid reputational harms from low scores but lack incentives to be transparency leaders. As policymakers around the world increasingly mandate certain types of transparency, this work reveals the current state of transparency for foundation model developers, how it may change given newly enacted policy, and where more aggressive policy interventions are necessary to address critical information deficits.