Anthropic is launching a new version of the miniature “Haiku” model

Anthropic on Wednesday released the Cloud Haiku 4.5, the latest version of its smallest model. The model is described as offering performance similar to the Sonnet 4 “at a third the cost and more than twice the speed,” according to a company blog post.

Humanitarian sites offer a set of new benchmark results to support these performance claims. In the company’s testing, Haiku scored 73% on the SWE-Bench test and 41% on the command-line-focused Terminal-Bench — lower than Sonnet 4.5, but on par with Sonnet 4, GPT-5, and Gemini 2.5 in every case. Tests show similar results for criteria for tool use, computer use, and visual thinking.

The new version of Haiku will become the default for all Anthropic’s free plans, and the company believes it will be particularly attractive to free versions of AI products, as it can provide significant capabilities while reducing server loads. The lightweight nature of the model also means that it is easier to deploy multiple Haiku clients in parallel or in conjunction with a more sophisticated model.

In a statement to the press, Mike Krieger, COO of Anthropic, said Haiku will make new publishing modes possible in production for the first time. “It opens up entirely new categories of what’s possible with AI in production environments — where Sonnet handles complex planning and Haiku-powered sub-agents execute quickly,” Krieger said. “We’re giving people a complete agent toolkit where each model has the right mix of intelligence, speed and cost for different parts of the business.”

The most compelling applications will likely come in software development tools, where Claude Code is already commonly used and latency is often a deciding factor. In remarks provided by Anthropic, Zencoder CEO Andrew Velev described the new version of Haiku as “opening up a whole new set of use cases.”

Haiku 4.5 comes after a series of high-profile launches for Anthropic: just two weeks away Sonnet 4.5 launch Two months later Opus 4.1 launchboth of which were hailed as state-of-the-art upon release. Previous version of Haiku Released in October 2024.