Anthropic's Claude Sonnet 5.5 Outperforms Newly Released GPT-6 Sol; OpenAI's Astra Remains Top Choice for Hardest Tasks

Anthropic has released Claude Sonnet 5.5 on September 28, a mid-tier AI model that outperforms OpenAI's newly released GPT-6 Sol across all benchmark categories, while OpenAI's flagship GPT-6 Astra continues to dominate on the most demanding reasoning and computer-use tasks. Both Sonnet 5.5 and GPT-6 Sol were released within days of each other at identical pricing—$2 per million input tokens and $10 per million output tokens—positioning them as direct competitors in the cost-conscious segment of the AI market.