kapynAI / Models

Claude Sonnet 5.5

Claude Sonnet 5.5 is Anthropic's new faster and cheaper mid-tier model. It delivers better benchmark performance than its predecessor at a lower cost while powering the free tier on claude.ai. However, early testing reveals that its extended thinking mode can occasionally over-think complex image generation tasks and exhaust its token budget.

Simon Willison·Sep 28, 2026

Opening Kapyn…