Anthropic launches Claude Haiku 5.5, its fastest model to date
What's the story
Anthropic has launched its latest artificial intelligence (AI) model, the Claude Haiku 5.5. The new version comes nearly a year after the last update to the Haiku model. Currently, Anthropic offers several models under the Claude brand, including Haiku (the smallest and cheapest), Sonnet (medium-sized and priced), and Opus (the largest and most expensive).
Model upgrade
New model designed for high-volume, cost-sensitive tasks
The launch of Claude Haiku 5.5 marks an upgrade from version 4.5 to 5.5, making it the third such upgrade in the last month after Opus and Sonnet.
Anthropic says that the new model is designed for high-volume, cost-sensitive tasks and can handle quick and repetitive workloads like summaries, compactions, database queries, and classification requests with ease.
Cost efficiency
Haiku 5.5 costs around 75% less to run
Anthropic claims that Claude Haiku 5.5 costs around 75% less to run than its predecessor, making it an affordable option for users.
The model also works well as a subagent on coding work with Opus 5.5 and Sonnet 5.5, thanks to its speed capabilities.
This makes it particularly suitable for speed-sensitive tasks like live customer support and browser use.
Model performance
Model comes with new effort setting to optimize for cost/intelligence
Anthropic says that Haiku 5.5 shows a major improvement over both Haiku 4.5 and OpenAI's GPT-6 Luna in terms of performance.
The new model also comes with an effort setting, which gives users the option to optimize for cost or intelligence.
This is likely the first Claude model to offer such a feature, giving it an edge over its predecessors.
Enhanced security
Haiku 5.5 shows fewer misaligned behaviors than predecessor
Haiku 5.5 shows major improvements in alignment evaluations compared to its predecessor, with fewer instances of misaligned behavior and a lower willingness to cooperate with misuse.
The model comes with stricter cybersecurity safeguards than Haiku 4.5, allowing a wider range of defensive tasks than Sonnet 5.5 while still blocking penetration testing techniques more likely to be used by attackers.
Model access
Claude Haiku 5.5 available on all major cloud platforms
Claude Haiku 5.5 is available on all platforms, including Amazon Web Services (AWS), Microsoft Azure, and Google Cloud.
The model is said to be good value for tasks with prompts of up to 100,000 tokens, which make up around 90% of requests to its predecessor.
Anthropic has also halved the price of Sonnet 5.5's cache reads by half, making it run around 20% cheaper on most agentic work.
Twitter Post
Official announcement
Introducing Claude Haiku 5.5: the cheapest, fastest, and most capable small model we’ve ever released.
— Claude (@claudeai) October 7, 2026
On average, it costs around 75% less to run than Claude Haiku 4.5. pic.twitter.com/jm06cZJfkV