Claude Haiku 5.5

Claude Haiku 5.5 is a fast model for focused coding tasks and quick, repetitive work. In its official announcement , Anthropic describes it as its fastest small model yet, with improvements over Haiku 4.5 in coding, visual reasoning, and computer use.

Choose Haiku in Ziva

Open the model picker, select Advanced, then choose Claude Haiku 5.5. Haiku 4.5 is retired in Ziva; choose 5.5 when continuing an existing chat that used it.

Haiku is a good fit for a targeted bug fix, a small code change, or a summary of how a script works. For complex changes spanning several systems, Anthropic recommends its larger Sonnet and Opus models instead.

Adjust reasoning effort

Haiku 5.5 is the first Haiku model with adjustable effort. In Ziva, choose a reasoning level from Low through Max; the default is High.

Use lower effort for straightforward requests, or increase it when a task needs more reasoning. Higher effort trades speed and cost for deeper reasoning, but does not make Haiku a substitute for a larger model on every task.