Anthropic launched Claude Haiku 4.5 today. It is the most compact variant of this generation of LLMs from Anthropic and promises to deliver performance close to that of GPT-5. Claude Sonnet 4.5 remains the better-performing model by a considerable margin, but Haiku's benchmark scores are not too far off from the larger LLM. Claude Haiku 4.5 "gives users a new option for when they want near-frontier performance with much greater cost efficiency."