Claude Sonnet 4, an advanced AI model Anthropic introduced in May. Recently, Anthropic launched Claude Sonnet 4.5, its latest premier AI offering. Claude Haiku 4.5 will be available to Claude subscribers on the Free plan.
According to a blog post from Anthropic, Claude Haiku 4.5 is over two times quicker than Sonnet 4 in delivering similar coding performance, with costs reduced to one-third of those of Sonnet 4. Benchmark data shared by Anthropic indicates that Claude Haiku 4.5 outperformed ChatGPT (GPT-5) and Gemini 2.5 Pro, in addition to Sonnet 4, in software engineering evaluations. Claude Haiku 4.5 also achieved impressive results in various benchmark tests, including agentic tool use, computer usage, visual reasoning, and more, as shown below.
AnthropicRegarding safety, Anthropic states that Claude Haiku 4.5 demonstrated a “statistically significantly lower overall rate of misaligned behaviors” compared to Sonnet 4.5 and Opus 4.1.” Consequently, Claude Haiku 4.5 is deemed Anthropic’s safest.
