Claude models top Agent Arena’s Code, Work and Chat rankings as of October 5, 2026

Agent Arena says its October 5, 2026, rankings put Claude Fable 5.1 (Max) first in Code and Work and Claude Sonnet 5.5 (Max) first in Chat. GPT 6 Astra (Max) ranks in the top four across all three categories, while Gemini 4 Argon (High) ranks fifth in Chat, 14th in Code and 12th in Work. Agent Arena says the rankings draw on live traces of agents tackling tasks submitted by people.