Anthropic’s Fable 5 spent three days as the most capable AI model ever released to the public. It topped the Chatbot Arena leaderboard, crushed OpenAI’s GPT 5. 5 on coding benchmarks by double-digit margins, and gave paying subscribers access to Mythos-class reasoning for the first time.
Source: [TNW](https://thenextweb.com/news/anthropic-fable-5-vs-openai-gpt-5-5-benchmark-comparison)