Anthropic launches Claude Haiku 5.5, its fastest and cheapest small model, and halves Sonnet 5.5 cache prices

Anthropic on October 7 released Claude Haiku 5.5, which the company describes in its launch post as “the cheapest, fastest, and most capable small model we’ve ever released.”

According to Anthropic, Haiku 5.5 is designed for high-volume, cost-sensitive tasks such as summaries, compactions, database queries and classification requests. It is meant to pair with Opus 5.5 and Sonnet 5.5 as a subagent on coding work, and, as the company’s fastest model to date at standard speed, to suit speed-sensitive uses such as live customer support and browser use. Only Anthropic’s Opus models in Fast Mode run faster.

Pricing. Anthropic says Haiku 5.5 costs around 75% less to run than Haiku 4.5 on average. It is priced 90% lower for requests of up to 100,000 tokens, which made up about 90% of Haiku 4.5 traffic, and 50% lower for longer requests. Input costs $0.10 per million tokens ($0.50 above 100,000 tokens) and output $0.50 per million ($2.50 above 100,000). Haiku 4.5 had cost $1 and $5 respectively, The New Stack noted.

Haiku 5.5 is the first Haiku-class model with an adjustable effort setting, letting users trade off cost against intelligence. In early customer testing cited by Anthropic, HubSpot said the model posted the best score it had seen on its CRM evaluation suite, at 92.8%, while Box said it scored 11 points higher than Haiku 4.5 at about half the latency.

Safety. Anthropic says Haiku 5.5 shows major improvements over Haiku 4.5 across almost all of its alignment evaluations. Its cybersecurity safeguards are more restrictive than Haiku 4.5’s but somewhat less restrictive than those on other recent models: they permit a wider range of defensive tasks but still block penetration testing and other techniques more likely to be used by attackers.

Other changes. Anthropic also halved the price of cache reads on Claude Sonnet 5.5, from $0.20 to $0.10 per million tokens, which it says makes Sonnet 5.5 around 20% cheaper on most agentic work. This week it is rolling out monthly API credits for Max and Team subscribers on the Claude Platform: $100 a month for Max 5x users, $200 for Max 20x users and up to $500 for Team subscribers, pooled across users. Its Python and TypeScript SDKs are gaining beta support for computer use and browser use.

Haiku 5.5 is available now on the Claude Platform as claude-haiku-5-5, as well as on Amazon Web Services, Google Cloud and Microsoft Azure. AWS announced availability on Amazon Bedrock the same day, and The Verge highlighted the model’s speed. According to The New Stack, it is the first new version of Anthropic’s smallest model in nearly a year and the company’s third 5.5 model in a month.