Hidden State

Evolution

See how the picture changed, day by day. The Today view shows where things stand now.

Sep 24Sep 28

A clearer
picture
over time.

Showing Mon, Sep 28, 2026

Anthropic’s mid-tier Sonnet now approaches Opus on one independent model index, at high token use.

Frontier

Previously: OpenAI released GPT-6 Sol and Luna, and Anthropic released Claude Opus 5.5, on September 22; no independent comparison identifies an overall leader.

Now: Anthropic’s Sonnet 5.5 ranks just behind Opus 5.5 on Artificial Analysis’s Intelligence Index at maximum effort, but uses more tokens; no overall leader is established.

Shifting and Settled unchanged