Anthropic releases Claude Haiku 5.5, its smallest and lowest-cost model

Anthropic/Claude models

Anthropic released Claude Haiku 5.5 on 7 October 2026. Anthropic describes it as the smallest and lowest-cost model it has released, built for high-volume work where cost matters. It follows Sonnet 5.5 and Opus 5.5 in the 5.5 family.

• Released 7 October 2026, as the smallest model in the Claude 5.5 family
• Built for high-volume work where cost matters most
• Anthropic's own announcement is the primary source; this summary takes only the release date and positioning from the report