After Anthropic released Opus 5.5, the dedicated configuration identifier for Claude Sonnet 5.5, “claude-sonnet-5-5”, has appeared in the official backend and is now undergoing a small-scale gray release through the Claude Code channel. Internal beta developers report that this new model outperforms GPT-6 Sol in pure frontend UI animation generation and everyday coding scenarios, while its advanced coding and agentic capabilities are already approaching those of GPT-6 Astra. It is priced at $2 per million input tokens, $10 per million output tokens, and only $0.20 per million tokens for cached reads.

Behind this is Anthropic’s competitive move aimed at OpenAI’s annual developer conference: technically matching the performance of top flagship models with lower inference costs, directly capturing users in cost-effective coding and development scenarios. This step almost squeezes out competitors at the same price point.