Claude Haiku 4.5 (Vertex AI (Anthropic))

Claude Haiku 4.5 sits at the small end of Anthropic's Claude family and is positioned as a low-latency option for interactive workloads such as chat assistants, customer service agents, pair programming, and rapid prototyping inside Claude Code. Anthropic describes it as delivering coding performance comparable to Claude Sonnet 4 while running at one-third the cost and more than twice the speed, and as surpassing Sonnet 4 on certain tasks, including computer use, which Anthropic highlights on a SWE-bench Verified comparison in its release materials. The intended deployment pattern is near-frontier quality paired with greater cost efficiency, and Anthropic explicitly suggests composing Haiku 4.5 with larger Claude siblings so a stronger model can plan or delegate while Haiku 4.5 handles quick, responsive turns.

In practice, Claude Haiku 4.5 is best understood as a speed-and-cost-tuned variant rather than a frontier research model: its strengths are responsiveness and economics on real-time tasks, multi-agent coding projects, and lightweight customer-facing assistants, where the combination of high intelligence and fast generation matters more than chasing top-of-leaderboard scores. Anthropic frames it as a complement to its flagship Claude Sonnet 4.5, letting teams reserve heavier reasoning for complex steps and route routine turns through Haiku 4.5 to keep latency and spend down. This makes the model a practical default for product teams that need dependable Claude behavior on a budget and want the option to escalate to a larger sibling when a request demands deeper reasoning.