Claude Haiku 4.5 is Anthropic’s small, fast AI model for low-latency applications, high-volume processing, coding, computer use, and sub-agent tasks. Anthropic released it on October 15, 2025, and it is available through the Claude API as claude-haiku-4-5-20251001.
What is Claude Haiku 4.5?
It is a hybrid reasoning model in Anthropic’s fast Haiku tier. It accepts text, images, and PDFs, supports a 200,000-token context window, and can produce up to 64,000 output tokens.
What makes it different?
Haiku focuses on speed and efficiency. It is suited to real-time assistants, customer support, interactive coding, sub-agents, and applications processing many requests. It also supports extended thinking, tool use, vision, prompt caching, and batch processing.
How does it compare with Sonnet 5 and Opus 5?
Haiku 4.5 is the fastest and least expensive model of the three, but it has a smaller context window and lower capability on the most demanding tasks. Sonnet 5 offers a stronger balance of speed and intelligence, while Opus 5 targets complex, long-running work.
How much does Claude Haiku 4.5 cost?
Standard pricing is $1 per million input tokens and $5 per million output tokens. Cache hits and refreshes cost $0.10 per million tokens, while cache writes have separate rates. The Batch API provides a 50% discount on input and output processing.
What are its strengths?
Anthropic reports a 73.3% score on SWE-bench Verified, an evaluation based on real-world software engineering tasks. The company also positions Haiku 4.5 for parallel execution, sub-agents, and latency-sensitive workloads.
What are its limitations?
Its 200,000-token context window is substantially smaller than the one-million-token context supported by Sonnet 5 and Opus 5. Its reliable knowledge cutoff is February 2025, with training data through July 2025, so current events require external sources or tools.
Although its coding performance is strong for its size, it should not be assumed to match larger Claude tiers on every task. Results vary with tools, scaffolding, prompting, and test conditions.
In short
Claude Haiku 4.5 is a practical choice when speed, cost, and request volume matter more than maximum capability. It fits real-time workflows, sub-agents, and interactive coding, with a smaller context window and an older knowledge cutoff than newer premium models.