Claude Opus 5 scored 30% on Arc AGI 3, roughly three times the next best model, and achieved a perfect 42 out of 42 on IMO 2026 without tool use, according to independent benchmarks. Anthropic describ…
Anthropic's Claude Opus 5 is priced at $5 per million input tokens and $25 per million output tokens, identical to Opus 4.8, but benchmark data shows reasoning effort peaks at medium for coding tasks,…
A 5-day project sprint during ARENA 8.0 found that prompt rephrasing can measurably impact alignment-relevant properties even on frontier models, though data were noisy and inconsistent across evals, …
OpenAI's GPT-4 led the Epoch Capabilities Index for about a year, but since Claude 3 Opus took the top spot in February 2024, the lead has changed hands 17 times with a median stay of just seven weeks…
Anthropic's Claude Fable 5 scored 161 on the Epoch Capabilities Index, surpassing OpenAI's GPT-5.5 Pro at 159, with dominant performances in math and software engineering benchmarks. The model achieve…