Yesterday, Anthropic introduced its cheapest, fastest and most capable small model: Claude Haiku 5.5. This model is designed for high-volume and cost-sensitive tasks, and it reliably handles quick and repetitive workloads.
Introducing Claude Haiku 5.5: the cheapest, fastest, and most capable small model we’ve ever released.
On average, it costs around 75% less to run than Claude Haiku 4.5. pic.twitter.com/jm06cZJfkV
— Claude (@claudeai) October 7, 2026
Claude Haiku 5.5
During evaluation, this latest model performed better than Haiku 4.5 and GPT-6 Luna models in Knowledge work, computer use, multidisciplinary reasoning, agentic coding and visual reasoning.
It is the first Haiku-class model that comes with an adjustable effort setting. This means users can decide whether to optimise for cost or intelligence. Haiku 5.5 is especially good value when used for tasks with prompts up to 100,000 tokens, which make up around 90% of requests to the previous Haiku models.
According to the company, Claude Haiku 5.5 shows major improvements across almost all alignment evaluations compared with Haiku 4.5. It showed fewer instances of misaligned behaviour and a lower willingness to cooperate with misuse.
Haiku 5.5’s cybersecurity safeguards are more restrictive than Haiku 4.5’s, but somewhat less restrictive than those applied to other recent models. In cybersecurity, they permit a wider range of defensive tasks than safeguards for Sonnet 5.5, but they still block penetration testing and other techniques more likely to be used by attackers.
Haiku 5.5’s biology safeguards are the same as for Sonnet 5, Sonnet 5.5 and Opus 5. They allow research biology questions but restrict access to requests that could likely cause harm.
Availability
Claude Haiku 5.5 is available now on all platforms, including Amazon Web Services, Google Cloud, and Microsoft Azure. On the Claude Platform, developers can get started with claude-haiku-5.5.
Price per 1 million tokens
Haiku 5.5 prompts up to/over 100K
- Cache reads: $0.01/ $0.05
- Cache writes: $0.125/ $0.625
- Input tokens: $0.10/ $0.50
- Output tokens: $0.50/$2.50
