Anthropic launches Claude Haiku 4.5, a smaller, cheaper AI model

Anthropic on Wednesday announced Claude Haiku 4.5, a small artificial intelligence model available as a lower-cost offering to all of the company’s users.

The model is fast and can outperform other larger models that were considered cutting edge just a few months ago, Anthropic said.

Claude Haiku 4.5 is more proficient in using computers than, for example, Claude Sonnet 4, a mid-size model launched by the company in May. It performs similarly to Claude Sonnet 4 and OpenAI’s newest model, GPT-5, in terms of coding, according to SWE-bench Verified, a set of tests that measures the software coding capabilities of an AI system.

“It punches way above its weight,” Mike Krieger, Anthropic’s chief product officer, told CNBC in an interview.

Claude Haiku 4.5 is available to free Anthropic users, and it is now the cheapest model available to paying users.

Anthropic is an AI startup developing a family of large language models called Claude. The company assigns new numbers to models as they advance through generations, but the smallest model in the family is usually called Haiku, the mid-size model is called Sonnet, and the largest model is Opus.

After OpenAI burst onto the scene with the launch of its ChatGPT chatbot in 2022, Anthropic launched a rival product, Claude, the following year. It is powered by the Anthropic family of templates and users can choose between free and paid tiers.

The launch of Claude Haiku 4.5 comes just weeks after the company announced Claude Sonnet 4.5 in September and Claude Opus 4.1 in August. Anthropic is working to release another model, likely an updated version of Opus, by the end of this year or early next year, Krieger said.

For paying users, Haiku models typically cost about a third of the cost of Anthropic’s Sonnet models, while Sonnet models are a fifth of the cost of its Opus models, Krieger said. Free Anthropic users can still choose to use Claude Sonnet 4.5, but they will benefit from more capacity with Claude Haiku 4.5 because it is smaller, he added.

Claude Sonnet 4.5 remains Anthropic’s highest-performing model, but the company said Claude Haiku 4.5 is ideal for users looking for fast, accurate responses.

“Even for my own use, even though it’s not as smart as Sonnet, I started using it by default on Claude, especially in the mobile app, because it’s just a lot quicker to get a response,” Krieger said.

The two models can also work together. Anthropic said Claude Sonnet 4.5 can create multi-step plans to solve complex problems, and Claude Haiku 4.5 can, for example, complete subtasks within those plans.

Running the models in parallel could be particularly useful for companies that want to use AI to tackle longer-term projects, Krieger said.

“You could ask Haiku to monitor financial data feeds – and because it’s a smaller, cheaper and faster model, it can do that with higher volume – and then pass its initial information to Sonnet to do further analysis,” he said.

Anthropic, which was No. 4 on CNBC’s 2025 Disruptor 50 list and is valued at $183 billion, serves more than 300,000 enterprise customers. Its annual revenue is approaching $7 billion this month, according to an Anthropic spokesperson.

The company has strived to keep pace with competitors like Google and OpenAI, whose valuation reached $500 billion. Following the launch of GPT-5 in August, OpenAI signed several multibillion-dollar infrastructure deals and released a short-form video application called Sora.

The hectic pace of the industry doesn’t give Anthropic much time to feel comfortable after a launch. While the company was carrying out training on Claude Sonnet 4.5, it had already started work on Claude Haiku 4.5.

“We’re really firing on all cylinders,” Krieger said.

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